JP2002300540A - Image signal processing device, image signal processing method, image display device using the same, program for executing each image signal processing method, and computer-readable medium storing the program - Google Patents

Abstract

(57) Abstract: The resolution of an image based on a second image signal (HD signal) obtained by converting a first image signal (SD signal) can be arbitrarily adjusted. It is possible to prevent a portion having an inappropriate resolution from occurring in an image. An arithmetic circuit 127 generates HD pixel data based on an estimation formula using coefficient data wi corresponding to a value of a parameter Q indicating resolution. Coefficient memory 1
At 31, coefficient data of each class corresponding to two discrete values m and m + 1 located near the value of the parameter Q is loaded from the information memory bank 132. Coefficient selection circuit 133
In which of the plurality of feature amount regions having different degrees of inappropriate resolution the feature amount around the position of interest constituting the HD signal to be created, and which of the values of the parameter Q from m to m + 1 SEL is generated based on whether the selection signal SEL is present. Thus, the coefficient memory 131
The coefficient data to be used is selected from the two coefficient data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an image signal processing apparatus, an image signal processing method, an image display apparatus using the same, and an information providing medium which are preferably applied when converting a video signal of a system into a high definition video signal. Specifically, when converting the first image signal into the second image signal, a feature amount related to a high-frequency component amount around the target position in the second image signal is detected, and a parameter indicating the resolution of the image is detected. By generating the pixel data of the target position in the second image signal by also referring to the other detected feature amounts, it is possible to prevent the occurrence of a portion having an inappropriate resolution in the image based on the second image signal. And an image signal processing device.

[0002]

2. Description of the Related Art Conventionally, for example, SD (S
tandard Definition) signal is H
Format conversion for converting to a D (High Definition) signal has been proposed. The 525i signal has 525 lines.
The book means an interlaced image signal, and 1050i
The signal means an interlaced image signal having 1050 lines.

FIG. 13 shows the pixel positional relationship between the 525i signal and the 1050i signal. Here, a large dot is a pixel of the 525i signal, and a small dot is 1050i.
It is a pixel of the signal. The pixel positions of the odd fields are indicated by solid lines, and the pixel positions of the even fields are indicated by broken lines. When converting a 525i signal to a 1050i signal,
In each of the odd and even fields, 525i
It is necessary to obtain four pixels of the 1050i signal corresponding to one pixel of the signal.

Conventionally, in order to perform the format conversion as described above, 1050i is calculated from pixel data of a 525i signal.
When obtaining the pixel data of the signal, the coefficient data of the estimation formula corresponding to the phase of each pixel of the 1050i signal with respect to the pixel of the 525i signal is stored in the memory, and the pixel data of the 1050i signal is obtained by the estimation formula using the coefficient data. It has been proposed to seek data.

[0005]

As described above, when the pixel data of the 1050i signal is obtained by the estimation formula, the resolution of the image based on the 1050i signal is fixed, which is the same as the conventional adjustment of contrast and sharpness. In addition, the desired resolution cannot be obtained according to the image content and the like.

Accordingly, the present invention enables a user to arbitrarily adjust the resolution of an image to a desired value.
It is an object of the present invention to provide an image signal processing device or the like that prevents occurrence of a portion having an inappropriate resolution in an image.

[0007]

An image signal processing apparatus according to the present invention is an image signal processing apparatus for converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data. A first data selection unit that selects a plurality of first pixel data located around a target position in the second image signal based on the first image signal; and a first data selection unit. Selected multiple first
A feature amount detection unit that detects a feature amount related to a high-frequency component amount around the target position based on the pixel data of (a), and a resolution parameter output unit that outputs a parameter indicating a resolution of an image based on a second image signal. Pixel data generating means for generating pixel data of the position of interest in the second image signal in accordance with the characteristic amount detected by the characteristic amount detecting means and the parameter output from the resolution parameter output means. .

For example, the pixel data generating means includes: coefficient data candidate generating means for generating coefficient data candidates of an estimation expression for a plurality of representative resolutions corresponding to the parameters output from the resolution parameter output means; Resolution specifying means for specifying one of a plurality of representative resolutions based on the characteristic amount detected by the means and the parameter output from the resolution parameter output means; and a coefficient generated by the coefficient data candidate generating means. A coefficient data selecting unit for selecting coefficient data corresponding to the resolution specified by the resolution specifying unit from the data candidates; and a plurality of coefficient data units located around the position of interest in the second image signal based on the first image signal. Data selecting means for selecting the second pixel data, and a plurality of second pixels selected by the second data selecting means. By using the coefficient data selected by the data and coefficient data selection means, and has a calculating means for calculating the pixel data of the target position based on the estimation equation.

An image signal processing method according to the present invention is an image signal processing method for converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data. A first step of selecting a plurality of first pixel data located around a target position in a second image signal based on one image signal; and a plurality of first pixel data selected in the first step A second step of detecting a feature amount related to a high-frequency component amount around the target position based on the pixel data, and a third step of outputting a parameter indicating a resolution of an image based on a second image signal; The feature amount detected in the second step and the third
The fourth step of generating pixel data of the target position in the second image signal in accordance with the parameters output in the step
And the following steps.

Further, the image display device according to the present invention comprises an image signal input means for inputting a first image signal comprising a plurality of pixel data, and a plurality of first image signals input from the image signal input means. Image signal processing means for converting and outputting a second image signal composed of pixel data of the following, image display means for displaying an image based on the second image signal output from the image signal processing means on an image display element, Resolution parameter output means for outputting a parameter indicating the resolution of the image based on the second image signal. An image signal processing unit configured to select a plurality of first pixel data located around a target position in the second image signal based on the first image signal;
A feature amount detection unit that detects a feature amount related to a high-frequency component amount around the target position based on the plurality of first pixel data selected by the first data selection unit; and a feature amount detection unit. And pixel data generating means for generating pixel data of a position of interest in the second image signal in accordance with the characteristic amount detected in the step (1) and the parameter output from the resolution parameter output means.

A program according to the present invention causes a computer to execute the above-described image signal processing method. A computer-readable medium according to the present invention stores the above-mentioned program.

In the present invention, a plurality of first pixel data located around a target position in the second image signal is extracted based on the first image signal, and based on the plurality of first pixel data, , A feature amount related to the high-frequency component amount around the target position is detected. This feature amount is obtained, for example, using the sum of absolute values of adjacent pixels in the plurality of first pixel data and the dynamic range in the plurality of first pixel data.

The resolution parameter output means outputs a parameter indicating the resolution of the image based on the second information signal. From the resolution parameter output means, a parameter indicating the resolution is generated by, for example, a key input operation or a knob rotation operation.

Then, pixel data of a target position in the second image signal is generated in accordance with the above-described feature amount and parameter. For example, pixel data is generated as follows.

That is, candidate coefficient data of an estimation formula is generated for a plurality of representative resolutions corresponding to the parameters. For example, if the value of the parameter is between discrete first and second values, the coefficients of two estimation formulas to obtain the resolutions corresponding to those first and second values Data is generated as coefficient data candidates.

Then, based on the characteristic amount and the parameter,
One of a plurality of representative resolutions is specified. For example, resolution selection information in a plurality of feature amount areas corresponding to the respective values of the parameters is stored in the storage unit, and the resolution is specified using this.
For example, when the resolution corresponding to the second value described above is higher than the resolution corresponding to the first value, the smaller the feature amount, the higher the probability of being specified as the second resolution even if the parameter value is small. .

Then, the coefficient data corresponding to the specified resolution is selected from the coefficient data candidates. Using the coefficient data selected in this way and a plurality of second pixel data located around the target position in the second image signal selected based on the first image signal, based on the estimation formula Thus, pixel data at the position of interest in the second image signal is calculated.

As described above, when converting the first information signal into the second information signal, the pixel at the position of interest in the second image signal is used by using the coefficient data corresponding to the value of the parameter indicating the resolution of the image. The data is calculated, and the user can arbitrarily adjust the resolution of the image to a desired value by changing the value of the parameter. Further, one coefficient data is selected and used from a plurality of coefficient data candidates corresponding to the parameter values, based on a feature amount related to a high-frequency component amount around the position of interest in the second image signal. It is possible to prevent a portion having an inappropriate resolution from occurring in an image based on the second image signal.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a television receiver 100 as an embodiment. The television receiver 100 obtains an SD signal called a 525i signal from a broadcast signal, converts the 525i signal into an HD signal called a 1050i signal, and displays an image based on the 1050i signal.

The television receiver 100 includes a microcomputer, and includes a system controller 101 for controlling the operation of the entire system and a remote control signal receiving circuit 102 for receiving a remote control signal. The remote control signal receiving circuit 102 is connected to the system controller 101, receives a remote control signal RM output according to a user operation from the remote control transmitter 200, and supplies an operation signal corresponding to the signal RM to the system controller 101. It is configured to be.

The television receiver 100 is supplied with a receiving antenna 105 and a broadcast signal (RF modulated signal) captured by the receiving antenna 105, and performs channel selection processing, intermediate frequency amplification processing, detection processing, and the like. A tuner 106 for obtaining an SD signal (525i signal) and a buffer memory 109 for temporarily storing the SD signal output from the tuner 106 are provided.

The television receiver 100 includes an image signal processing unit 110 for converting an SD signal (525i signal) temporarily stored in the buffer memory 109 into an HD signal (1050i signal), Display unit 1 for displaying an image based on the HD signal output from 110
11, an OSD (On Screen Display) circuit 112 for generating a display signal SCH for displaying characters, figures, and the like on the screen of the display unit 111, and the display signal SCH A synthesizing unit 113 for synthesizing with the HD signal output from 110 and supplying the HD signal to the display unit 111. The display unit 111 is, for example, a CRT (cathode-ray tube) display or an LCD (liquid crystal display)
And the like.

The operation of the television receiver 100 shown in FIG. 1 will be described. The SD signal (52
5i) is supplied to the buffer memory 109 and is temporarily stored. Then, the SD signal temporarily stored in the buffer memory 109 is supplied to the image signal processing unit 110 and is converted into an HD signal (1050i signal).
That is, in the image signal processing unit 110, pixel data (hereinafter, referred to as “HD pixel data”) that forms the HD signal is obtained from pixel data that forms the SD signal (hereinafter, referred to as “SD pixel data”). This image signal processing unit 11
0 is supplied to the display unit 111, and the H signal is displayed on the screen of the display unit 111.
An image based on the D signal is displayed.

Further, the user can adjust the resolution of an image displayed on the screen of the display unit 111 by operating the remote control transmitter 200. For example, by pressing the up key and the down key, or rotating a knob such as a jog dial in the resolution selection mode, the image signal processing unit 1 is sent from the system controller 101.
It is possible to change the value of the parameter Q that indicates the resolution and that is supplied to the.

In the image signal processing section 110, as will be described later, HD pixel data is calculated by an estimation equation. As the coefficient data of the estimation equation, data corresponding to the value of the parameter Q described above is used. Thereby, the resolution of the image based on the HD signal output from the image signal processing unit 110 corresponds to the value of the parameter Q.

When the value of the parameter Q is changed by the user's operation of the remote control transmitter 200, the parameter Q is displayed on the screen of the display unit 111.
Is displayed. Although not shown here, this display is performed using numerical values or bar graphs. The user can change the value of the parameter Q with reference to this display.

When the value of the parameter Q is displayed on the screen as described above, the system controller 101 supplies display data to the OSD circuit 112. The OSD circuit 112 generates a display signal SCH based on the display data, and supplies the display signal SCH to the display unit 111 via the synthesizer 113.

Next, the details of the image signal processing section 110 will be described. The image signal processing unit 110 includes a buffer memory 1
09 from the SD signal (525i signal) stored in
There are first to third tap selection circuits 121 to 123 for selectively extracting and outputting data of a plurality of SD pixels located around the target pixel related to the HD signal (1050i signal).

The first tap selection circuit 121 selectively extracts data of SD pixels (referred to as "prediction taps") used for prediction. Second tap selection circuit 1
Reference numeral 22 is for selectively extracting data of SD pixels (referred to as “space class taps”) used for class classification corresponding to the level distribution pattern of the SD pixel data. The third tap selection circuit 123 selectively extracts data of SD pixels (referred to as “motion class taps”) used for class classification corresponding to motion. When a space class is determined using SD pixel data belonging to a plurality of fields, the space class also includes motion information.

Further, the image signal processing section 110 detects a level distribution pattern of space class tap data (SD pixel data) selectively extracted by the second tap selection circuit 122, and based on this level distribution pattern. It has a space class detection circuit 124 that detects a space class and outputs the class information.

In the space class detection circuit 124, for example,
An operation for compressing each SD pixel data from 8-bit data to 2-bit data is performed. Then, from the space class detection circuit 124, compressed data corresponding to each SD pixel data is output as space class information. In the present embodiment, ADRC (Adaptive Dyn
Data compression is performed by amic range coding. As information compression means, other than ADRC, DP
CM (prediction coding), VQ (vector quantization), or the like may be used.

Originally, ADRC is a VTR (Video Tape R)
ecorder) is an adaptive requantization method developed for high-performance coding. However, since local patterns at the signal level can be efficiently expressed with a short word length, it is suitable for use in the data compression described above. Things. When using ADRC, the maximum value of the space class tap data (SD pixel data) is MAX, the minimum value is MIN, and the dynamic range of the space class tap data is DR (= MAX-MIN +
1) Assuming that the number of requantization bits is P, for each SD pixel data ki as data of a space class tap,
By the operation of the expression (1), a requantized code qi as compressed data is obtained as space class information. However, in Expression (1), [] means truncation processing. As the data of the space class tap, Na S
When there is D pixel data, i = 1 to Na. qi = [(ki-MIN + 0.5). 2 ^P / DR] (1)

The image signal processing unit 110 detects a motion class mainly representing the degree of motion from the data (SD pixel data) of the motion class tap selectively extracted by the third tap selection circuit 123. And a motion class detection circuit 125 for outputting the class information.

In the motion class detection circuit 125, the third
, A difference between frames is calculated from the motion class tap data (SD pixel data) mi and ni selectively extracted by the tap selection circuit 123, and threshold processing is performed on the average value of the absolute values of the differences. Then, a motion class, which is an index of the motion, is detected. That is, in the motion class detection circuit 125, the average value AV of the absolute value of the difference is calculated by Expression (2). Third tap selection circuit 123
For example, as class tap data, six SD pixel data m1 to m6 and six SD pixel data
When the pixel data n1 to n6 are extracted, Nb in Expression (2) is 6.

[0035]

(Equation 1)

Then, in the motion class detection circuit 125,
The average value AV calculated as described above is compared with one or a plurality of threshold values, and class information MV of the motion class is obtained.
Is obtained. For example, three thresholds th1, th2,
th3 (th1 <th2 <th3) is prepared, and when detecting four motion classes, MV when AV ≦ th1
= 0, th1 <AV ≦ th2, MV = 1, th2
MV = 2 when <AV ≦ th3, and MV = 3 when th3 <AV.

The image signal processing section 110 also includes a re-quantization code qi as the class information of the space class output from the space class detection circuit 124 and the class information MV of the motion class output from the motion class detection circuit 125. And a class synthesizing circuit 126 for obtaining a class code CL indicating a class to which the pixel data (pixel data at the target position) of the HD signal (1050i signal) to be created belongs.

In the class synthesizing circuit 126, the calculation of the class code CL is performed by the equation (3). In addition,
In Equation (3), Na indicates the number of data (SD pixel data) of the space class tap, and P indicates the number of requantization bits in ADRC.

[0039]

(Equation 2)

The image signal processing section 110 has a coefficient memory 131. The coefficient memory 131 stores coefficient data of an estimation formula used in the estimation prediction operation circuit 127 described later. This coefficient data is SD
The signal (525i signal) is converted to the HD signal (1050i signal)
This is information used when converting to. This coefficient memory 1
The class code CL output from the class synthesizing circuit 126 and the coefficient selection signal SEL output from a coefficient selection circuit 133 described later are supplied to 31 as read address information. The coefficient data wi corresponding to the class code CL and the coefficient selection signal SEL is read from the coefficient memory 131, and supplied to the estimated prediction operation circuit 127.

The image signal processing section 110 has an information memory bank 132. In the present embodiment, the parameter Q can be changed between 0 and 8. The information memory bank 132 has 0, 1,.
.. The coefficient data of each class at nine resolutions corresponding to the discrete values of 8 are stored in advance. here,
It is assumed that the resolution increases as the value of the parameter Q increases. A method of generating coefficient data corresponding to the nine resolutions will be described later.

As described above, the 525i signal is set to 1
When converting to a 050i signal, it is necessary to obtain four pixels of the 1050i signal corresponding to one pixel of the 525i signal in each of the odd and even fields. for that reason,
A certain class of coefficient data at a certain resolution is odd,
It consists of coefficient data corresponding to four pixels in a 2 × 2 unit pixel block constituting the 1050i signal in each of the even fields. The four pixels in the 2 × 2 unit pixel block have different phase relationships from each other corresponding to the pixels of the 525i signal. A method of generating coefficient data corresponding to the plurality of resolutions will be described later.

As described above, the user operates the operation unit of the remote control transmitter 200 to press the up key and the down key, or to rotate the knob such as the jog dial or the like. The value of the parameter Q supplied to 110 can be changed. The parameter Q is supplied to the information memory bank 132, and two discrete values m, m + 1 (m = 0, 1,...) Located near the value of the parameter Q are supplied from the information memory bank 132 to the coefficient memory 131. The coefficient data corresponding to (7) is loaded.

That is, when 0 ≦ Q ≦ 1, Q =
When the coefficient data corresponding to 0 and 1 satisfies 1 <Q ≦ 2, the coefficient data corresponding to Q = 1 and 2 and when 2 <Q ≦ 3 the coefficient data corresponding to Q = 2 and 3. Where 3 <Q ≦
When it is 4, the coefficient data corresponding to Q = 3, 4 is 4
When <Q ≦ 5, coefficient data corresponding to Q = 4,5 is satisfied. When 5 <Q ≦ 6, coefficient data corresponding to Q = 5,6 is satisfied. When 6 <Q ≦ 7. When the coefficient data corresponding to Q = 6, 7 is 7 <Q ≦ 8, the coefficient data corresponding to Q = 7, 8 is loaded from the information memory bank 132 to the coefficient memory 131.

The image signal processing section 110 has a coefficient selection circuit 133 for generating a coefficient selection signal SEL. The coefficient selection signal SEL is supplied as read address information to the coefficient memory 131 as described above, and is transmitted from the information memory bank 132 to the coefficient memory 13.
It is used to select one coefficient data from the coefficient data corresponding to the two discrete values of the parameter Q loaded and stored in 1.

FIG. 2 shows the configuration of the coefficient selection circuit 133. The coefficient selection circuit 133 includes the feature amount detection unit 14
1, a feature amount memory 142, a feature amount area determination unit 143, an area detection unit 144, and a coefficient selection signal generation unit 145.

The feature amount detection unit 141 is provided in the buffer memory 1
09 is temporarily stored in the SD signal (5
25i) is to detect the characteristic amount CH for each SD pixel constituting the 25i signal). In the present embodiment, the feature amount CH corresponding to a certain SD pixel (pixel of interest) is a value obtained by taking the square root of the product of the dynamic range DR and the activity ACT in a block of a predetermined size around the SD pixel ( ＤＲ (DR × ACT) The block size is
For example, 5 × 5.

As shown in FIG. 3, the dynamic range DR is data x _{i−2, j + 2 to} x _{i + 2 of} 25 SD pixels included in a 5 × 5 block centered on the target pixel. _{, j-2} , when the maximum value is MAX and the minimum value is MIN,
It is defined by equation (4). In FIG. 3, the coordinates of the pixel of interest are (i, j). DR = MAX-MIN (4)

In the activity ACT, as shown in FIG. 4, the coordinates of the target pixel are set to (i, j), and 25 SDs included in a 5 × 5 block centered on the target pixel are set.
When pixel data is x _{i−2, j + 2} to x _{i + 2, j−2} ,
It is defined by equation (5). Here, i ₁ = i−2,.
·, I + 1, i ₂ = i-2, ..., i + 2, j ₁ = j-
2,..., J + 2, j ₂ = j−2,.

[0050]

(Equation 3)

FIG. 5 shows a model of a part detected by the dynamic range DR and the activity ACT. When the dynamic range DR is used, the outline of the image is detected as indicated by the bold line on the upper right in FIG. On the other hand, when the activity ACT is used, a high-frequency area surrounded by a low-frequency area of the image is detected as indicated by a bold line at the lower right in FIG. As described above, the feature amount CH
Since this is defined by √ (DR × ACT), this feature amount CH
Is used, both the outline of the image and the high-frequency region surrounded by the low-frequency region of the image are detected.

As described above, the 525i signal is
When converting to an i signal, in each of the odd and even fields, 10
The four pixels of the 50i signal are obtained as estimation pixels using an estimation formula. Therefore, detecting the characteristic amount CH corresponding to each pixel constituting the SD signal (525i signal) by the characteristic amount detection unit 141 means that the HD signal (1050i
That is, the feature amount CH related to the high-frequency component amount around each of the four pixels (pixel of interest) constituting the signal) is detected.

The feature amount detection unit 141 is provided in the buffer memory 1
For example, the detection process of the feature amount CH for the SD signal of a certain field stored in 09 is performed in a vertical blanking period. The feature amount memory 142 stores a feature amount CH corresponding to each SD pixel for one field detected by the feature amount detection unit 141 during a certain vertical blanking period.

The feature amount area determination unit 143 uses the feature amounts CH stored in the feature amount memory 142 and corresponding to all the SD pixels in a certain field to determine the range from the minimum value to the maximum value of the feature amount CH. Is divided into four regions to determine four feature amount regions. Feature amount area determination unit 143
Performs this feature amount area determination processing during the vertical blanking period. In this case, four feature amount regions are determined such that the number of feature amounts CH included in each feature amount region corresponding to all SD pixels is substantially equal.

FIG. 6 shows a characteristic amount CH corresponding to all SD pixels.
3 shows a histogram model of FIG. CHmin indicates the minimum value of the characteristic amount CH, and CHmax indicates the maximum value of the characteristic amount CH. Ra, Rb, Rc, and Rd are four feature amount regions, and Na, Nb, Nc, and Nd indicate the number included in each feature amount region among feature amounts CH corresponding to all SD pixels. In this case, the feature amount regions Ra, Rb, Rc, and Rd are determined so that the numbers Na, Nb, Nc, and Nd are substantially equal.

Here, the feature amount regions Ra, Rb, Rc, R
Consider the significance of d. Ra, Rb, Rc, Rd
In the case of generating HD pixel data from SD pixel data using coefficient data for obtaining the same resolution over the entire screen since the feature amount CH is large and the high-frequency component amount is large in the order of Where the feature amount CH is detected, the resolution tends to be inappropriate. A, b,
c and d indicate locations in the screen where the feature CH is detected in the feature regions of Ra, Rb, Rc, and Rd, respectively. Assuming that the degree of inappropriate resolution (the degree of failure) at each of these locations is pa, pb, pc, pd, pa <
pb <pc <pd.

The area detecting section 144 includes a feature amount detecting section 141.
In the vertical effective scanning period, the feature amount CH corresponding to each SD pixel detected in a certain vertical blanking period and stored in the feature amount memory 142 is sequentially extracted.
The feature amount CH corresponding to the pixel is determined by the feature amount regions Ra, Rb, Rc, and R determined by the feature amount region determination unit 143 described above.
d), and the detection information DET
Is output.

The coefficient selection signal generator 145 generates the coefficient selection signal SEL from the detection information DET from the area detector 144 and the value of the parameter Q supplied from the system controller 101.

The coefficient selection signal generating section 145 performs the above-described feature amount areas Ra, Rb, R corresponding to each value of the parameter Q.
It has a ROM (read only memory) 146 as storage means for storing the resolution selection information RES for c and Rd.

FIG. 8 schematically illustrates the resolution selection information RES stored in the ROM 146. In this figure, in a range (first range) in which “a” is described, when the feature amount CH is included in the feature amount region Ra, RES is set.
= 1, and the feature amount CH is equal to the feature amount regions Rb, Rc, and Rd.
Means that RES = 0 when “a,
b ”(the second range), the feature amount CH
Is included in the feature amount regions Ra and Rb, RES = 1, and when the feature amount CH is included in the feature amount regions Rc and Rd, RES = 0, and “a, b, c” is described. RES = 1 when the feature amount CH is included in the feature amount regions Ra, Rb, and Rc in the range (third range),
When the feature amount CH is included in the feature amount region Rd, RES = 0
In the range (a fourth range) in which “a, b, c, d” is described, the feature amount CH is equal to the feature amount region R.
a, Rb, Rc, and Rd
It means that S = 1.

In this figure, i <Q ≦ (i +
0.25) corresponds to the first range, and (i + 0.25) <
Q ≦ (i + 0.5) corresponds to the second range, and (i + 0.
5) <Q ≦ (i + 0.75) corresponds to the third range,
(I + 0.75) <Q ≦ (i + 1) corresponds to the fourth range. Here, i = 0, 1,..., 7. In addition,
When Q = 0, the feature amount CH is equal to the feature amount regions Ra and R
RES = 0 even when included in any of b, Rc, and Rd
It is.

The coefficient selection signal generator 145 extracts from the ROM 146 the detection information DET from the area detector 144 and the resolution selection information RES corresponding to the value of the parameter Q supplied from the system controller 101. Is output as a coefficient selection signal SEL. For example, if the value of the parameter Q is 0.4 and the detection information D
When ET indicates that the feature value CH is included in the feature value area Ra, SEL = 1 is extracted from the ROM 146, and 1 is output as the coefficient selection signal SEL.

The coefficient selection signal SEL output from the coefficient selection signal generator 145 is also an output of the coefficient selection circuit 133. As described above, the coefficient selection signal SEL output from the coefficient selection circuit 133 is supplied to the coefficient memory 131 as read address information as described above. The coefficient memory 131 (see FIG. 1) corresponds to two discrete values m, m + 1 (m = 0, 1,..., 7) located near the value of the parameter Q from the information memory bank 132 as described above. When SEL = 0, the coefficient data corresponding to the discrete value m is to be read, and when SEL = 1, the coefficient data corresponding to the discrete value m + 1 is to be read.

Returning to FIG. 1, the image signal processing unit 11
0 is the pixel data of the HD signal to be created from the prediction tap data (SD pixel data) xi selectively extracted by the first tap selection circuit 121 and the coefficient data wi read from the coefficient memory 131 (attention). An estimated prediction calculation circuit 127 for calculating the pixel data (y) at the position is provided.

As described above, when converting an SD signal (525i signal) to an HD signal (1050i signal),
Since it is necessary to obtain four pixels of the HD signal for one pixel of the SD signal, the estimation prediction operation circuit 127
For each 2 × 2 unit pixel block constituting the D signal, the HD
Pixel data is generated.

In other words, the estimation prediction operation circuit 127 has the prediction tap data xi corresponding to the data of four pixels in the unit pixel block (pixel data at the position of interest) from the first tap selection circuit 121 and the coefficient memory The coefficient data wi corresponding to the four pixels constituting the unit pixel block is supplied from 131, and the four pixels constituting the unit pixel block are supplied.
The pixel data y _{1 to} y ₄ are individually calculated by the estimation formula of Expression (6).

[0067]

(Equation 4)

[0068] Also, the image signal processing unit 110, a 4 pixel data y ₁ ~y ₄ of constituting the unit pixel block are sequentially output from the estimation predictive calculating circuit 127, and line sequence 10
Post-processing circuit 128 that outputs in the format of a 50i signal
have.

Next, the operation of the image signal processing section 110 will be described. From the SD signal (525i signal) stored in the buffer memory 109, the second tap selection circuit 122
Then, data (SD pixel data) of a space class tap located around four pixels (pixels at a position of interest) in a unit pixel block constituting an HD signal (1050i signal) to be created is selectively extracted. The data (SD pixel data) of the space class tap selectively extracted by the second tap selection circuit 122 is supplied to the space class detection circuit 124. In this space class detection circuit 124, each SD pixel data as the data of the space class tap is subjected to ADRC processing, and is regenerated as class information of a space class (mainly a class classification for representing a waveform in space). The quantization code qi is obtained (see equation (1)).

Further, based on the SD signal (525i signal) stored in the buffer memory 109, the third tap selection circuit 123 generates an HD signal (1050i signal) to be created.
Of motion class taps (SD) located around four pixels (pixels of the position of interest) in the unit pixel block constituting
Pixel data) is selectively extracted. The data (SD pixel data) of the motion class tap selectively extracted by the third tap selection circuit 123 is supplied to the motion class detection circuit 125. The motion class detection circuit 125 obtains class information MV of a motion class (mainly a class classification for representing a degree of motion) from each SD pixel data as motion class tap data.

The class information MV and the above-mentioned requantized code qi are supplied to the class synthesizing circuit 126. The class synthesizing circuit 126 generates an HD signal (1050) to be created from the class information MV and the requantization code qi.
For each unit pixel block constituting the (i signal), a class code CL indicating the class to which the data of the four pixels in the unit pixel block (pixel data at the position of interest) belongs is obtained (see equation (3)). And this class code CL is
It is supplied to the coefficient memory 131 as read address information.

Further, the coefficient selection circuit 13 is obtained from the SD signal (525i signal) stored in the buffer memory 109.
In 3, a coefficient selection signal SEL corresponding to four pixels (pixels of a position of interest) in the unit pixel block is generated for each unit pixel block constituting the HD signal (1050i signal) to be created.

That is, as shown in FIG. 2, the SD signal (525i signal) stored in the buffer memory 109 is supplied to the feature amount detection unit 141 of the coefficient selection circuit 133, and this feature amount detection unit 141 A feature amount CH = √ (DR × ACT) is detected for each SD pixel constituting the SD signal. Then, the feature amount CH corresponding to one field of the SD signal detected in a certain vertical blanking period is stored in the feature amount memory 142 by the feature amount detection unit 141.

As described above, the 525i signal is
When converting to an i signal, in each of the odd and even fields, 10
The four pixels of the 50i signal are obtained as estimation pixels using an estimation formula. Therefore, detecting the characteristic amount CH corresponding to each pixel constituting the SD signal (525i signal) by the characteristic amount detection unit 141 means that the HD signal (1050i
That is, the feature amount CH corresponding to each of the four pixels (pixel of interest) constituting the signal is detected.

Further, in the feature amount area determining unit 143,
The feature amount CH corresponding to the SD signal for one field stored in the feature amount memory 142 during a certain vertical blanking period
Is used to divide the range from the minimum value CHmin to the maximum value CHmax of the feature amount CH corresponding to all SD pixels into four regions to determine four feature amount regions Ra, Rb, Rc, and Rd (FIG. 6). In this case, the ranges of the four feature amount regions Ra, Rb, Rc, and Rd are determined so that the number of feature amounts CH included in each feature amount region corresponding to all SD pixels is substantially equal.

Then, the SD signals for one field stored in the feature memory 142 during a certain vertical blanking period are sequentially extracted in the subsequent vertical effective scanning period and supplied to the area detection unit 144, and the signals corresponding to each SD pixel are obtained. Feature quantity CH
Is included in any of the feature amount regions Ra, Rb, Rc, and Rd described above. This detection information DET is supplied to the coefficient selection signal generator 145.

The parameter Q is further supplied from the system controller 101 to the coefficient selection signal generator 145. ROM of the coefficient selection signal generator 145
As described above, the resolution selection information RES in the feature amount regions Ra, Rb, Rc, and Rd corresponding to each value of the parameter Q is stored in 146. In the coefficient selection signal generator 145, the detection information DE from the area detector 144 is output.
T and resolution selection information RES corresponding to the value of the parameter Q supplied from the system controller 101 are stored in the ROM.
146.

Then, the extracted coefficient selection information R
ES is the output of the coefficient selection signal generation unit 145, and thus the coefficient selection circuit 133. Therefore, the coefficient selection circuit 13
3, the coefficient selection signal SE corresponding to four pixels (pixels at the target position) in each unit pixel block constituting the HD signal (1050i signal) to be created.
L will be output. This coefficient selection signal SEL
Is supplied to the coefficient memory 131 as read address information.

The coefficient memory 131 stores, from the information memory bank 132, each class of two discrete values m, m + 1 (m = 0, 1,..., 7) located near the value of the parameter Q. The coefficient data has been loaded. Such an operation of loading the coefficient data is performed, for example, when the value of the parameter Q is changed and the coefficient data to be stored in the coefficient memory 131 needs to be changed.

As described above, the class code CL and the coefficient selection signal CL are supplied as read address information to the coefficient memory 131, so that the coefficient memory 131 corresponds to the class code CL and has the coefficient selection signal SEL.
Is read out and supplied to the estimation prediction operation circuit 127. In this case, when SEL = 0, the coefficient data corresponding to the discrete value m is read, and S
When EL = 1, coefficient data corresponding to the discrete value m + 1 is read.

In the first tap selection circuit 121,
The SD signal (52
5i signal), data (SD pixel data) of prediction taps located around four pixels (pixels of interest) in a unit pixel block constituting an HD signal to be created (1050i signal) are selectively extracted. . The prediction tap data (SD pixel data) xi selectively extracted by the first tap selection circuit 121 is calculated by an estimated prediction operation circuit 127.
Supplied to

In the estimation / prediction calculation circuit 127, the data (SD pixel data) xi of the prediction tap and the coefficient memory 131
And a four pixels coefficient data wi to be more read, the unit pixel 4 pixel data y ₁ ~y ₄ of the block constituting the HD signal to be produced is individually computed ((6) refer). Then, the estimation prediction operation circuit 12
Data y ₁ ~y ₄ of four pixels are sequentially output from 7 is supplied to the post-processing circuit 128. This post-processing circuit 128
The estimation predictive calculating circuit 127 4 data y ₁ ~y ₄ pixels are sequentially output from the line sequential turned into outputs in the format of 1050i signal. That is, the post-processing circuit 128 outputs a 1050i signal as an HD signal.

As described above, the parameter Q supplied from the system controller 101 is stored in the coefficient memory 131.
Two discrete values m, m + 1 (m =
0, 1,..., 7) are loaded from the information memory bank 132. Therefore, when the user operates the remote control transmitter 200 to change the value of the parameter Q, the coefficient memory 131
Are also changed, and the pixel data of the HD signal is generated in the estimation / prediction calculation circuit 127 in accordance with the value of the parameter Q. Therefore, by changing the value of the parameter Q, the user can arbitrarily adjust the resolution of the image based on the HD signal to a desired value as in the conventional adjustment of contrast and sharpness.

The two discrete values m and m + 1 located near the value of the parameter Q stored in the coefficient memory 131
Among the coefficient data of each class corresponding to (m = 0, 1,..., 7), the coefficient data used when the estimation prediction operation circuit 127 actually generates the pixel data of the HD signal is
It is determined based on the coefficient selection signal SEL generated by the coefficient selection circuit 133. That is, what kind of characteristic amount area includes the degree (the degree of failure) in which the characteristic amount CH around the four pixels (the pixel at the position of interest) in the unit pixel block constituting the HD signal to be created has an inappropriate resolution. , And whether the value of the parameter Q is between m and m + 1, it is determined whether to use the coefficient data corresponding to the discrete value m or to use the coefficient data corresponding to the discrete value m + 1. Incidentally, the coefficient data corresponding to the discrete value m + 1 is for obtaining a higher resolution than the coefficient data corresponding to the discrete value m.

For example, as the value of the parameter Q becomes closer to m, the discrete value m is obtained only when the characteristic amount CH is included in a characteristic amount region in which the degree of inappropriate resolution (the degree of failure) is low.
The coefficient data corresponding to +1 is used (see FIG. 8).
As a result, a portion where the feature amount CH is included in the feature amount region having a high degree of inappropriate resolution (failure degree) is
Inappropriate resolution can be prevented, and the image quality of the image based on the HD signal can be improved.

FIG. 9 shows a case where the positions a to d in the screen are in the same state as described with reference to FIG. 7, and when the value of the parameter Q changes from m to m + 1, This indicates whether coefficient data corresponding to m or the discrete value m + 1 is used.

When Q = m, as shown in FIG. 9A, the coefficient data wm corresponding to the discrete value m is used at all points a to d. When m <Q ≦ m + 0.25, as shown in FIG. 9B, the coefficient data wm + 1 corresponding to the discrete value m + 1 is used at the point a, and b to d
Is used, the coefficient data wm corresponding to the discrete value m is used. If m + 0.25 <Q ≦ m + 0.5, as shown in FIG. 9C, coefficient data wm + 1 corresponding to a discrete value m + 1 is used at a and b, and c and d of c and d are used. The coefficient data wm corresponding to the discrete value m is used at each point. m +
When 0.5 <Q ≦ m + 0.75, FIG. 9D
As shown in (1), the coefficient data wm + 1 corresponding to the discrete value m + 1 is used at the points a to c, and the coefficient data wm corresponding to the discrete value m is used at the point d. Further, m + 0.
If 75 <Q ≦ m + 1, as shown in FIG. 9E, the coefficient data wm + 1 corresponding to the discrete value m + 1 is used at all the points a to d.

In the above-described embodiment, the feature amount CH related to the high-frequency component amount around the target pixel is represented by √ (DR × ACT). However, the present invention is not limited to this. Not something. The feature amount CH may be any as long as the degree of inappropriate resolution (degree of failure) can be classified stepwise when an HD signal is obtained using coefficient data for obtaining the same resolution.

In the above-described embodiment, for simplicity, the range from the minimum value CHmin to the maximum value CHmax of the characteristic amount CH is divided into four regions to determine four characteristic amount regions Ra to Rd. 6 (see FIG. 6), and correspondingly, each of the discrete values of the parameter Q is divided into four ranges (see FIG. 8). It is assumed to be 10.

In the above embodiment, all SD
Although the numbers Na, Nb, Nc, and Nd included in each feature amount region among the feature amounts CH corresponding to the pixels are set to be substantially equal, the numbers need not always be equal. Where the number N
By making a, Nb, Nc, and Nd substantially equal, a change in the resolution of the HD image proportional to the change in the value of the parameter Q can be expected.

Next, a method of generating coefficient data corresponding to nine resolutions corresponding to discrete values of 0, 1,..., 8 of the parameter Q stored in the information memory bank 132 will be described. The coefficient data is generated in advance by learning.

First, the learning method will be described.
Coefficient data wi (i = 1 to 1) based on the estimation equation of equation (6)
Here, an example is shown in which n) is obtained by the least square method. As a generalized example, X is input data, W is coefficient data,
Consider the observation equation (7) with Y as the predicted value. In the equation (7), m indicates the number of learning data, and n indicates the number of prediction taps.

[0093]

(Equation 5)

The least squares method is applied to the data collected by the observation equation (7). Based on the observation equation (7), the residual equation (8) is considered.

[0095]

(Equation 6)

From the residual equation of equation (8), the most probable value of each wi is considered to be the case where the condition for minimizing e ² in equation (9) is satisfied. That is, the condition of equation (10) may be considered.

[0097]

(Equation 7)

That is, n conditions based on i in equation (10) are considered, and w ₁ , w ₂ ,..., W _n satisfying these conditions may be calculated. Thus, from the residual equation of equation (8), (1
Equation 1) is obtained. Further, the equation (12) is obtained from the equations (11) and (7).

[0099]

(Equation 8)

Then, from equations (8) and (12),
The normal equation of Expression (13) is obtained.

[0101]

(Equation 9)

The normal equation of the equation (13) is expressed by the number n of unknowns.
Since it is possible to make the same number of equations as
The most probable value of i can be obtained. In this case, simultaneous equations are solved using a sweeping-out method (Gauss-Jordan elimination method) or the like.

FIG. 10 shows a coefficient data generating device 150 for generating coefficient data based on the concept described above. The coefficient data generation device 150 performs an input terminal 151 to which an HD signal (1050i signal) as a teacher signal is input, and performs horizontal and vertical thinning processing on the HD signal to convert an SD signal as a student signal. And an SD signal generating circuit 152 for obtaining the same.

The parameter Q is supplied to the SD signal generation circuit 152 as a control signal. This parameter Q
Is a television receiver 100 shown in FIG.
This corresponds to the parameter Q output from 01. However, here, the value of the parameter Q is 0,
Only nine discrete values of 1,..., 8 are taken.

In the SD signal generation circuit 152, the horizontal and vertical bands of the filter used when generating the SD signal from the HD signal are varied according to the value of the parameter Q. This filter includes, for example, a one-dimensional Gaussian filter that limits a horizontal band and a one-dimensional Gaussian filter that limits a vertical band. This one-dimensional Gaussian filter is expressed by equation (14).

[0106]

(Equation 10)

In this case, a one-dimensional Gaussian filter having a frequency characteristic corresponding to the discrete value of Q can be obtained by changing the value of the standard deviation σ stepwise according to the discrete value of Q. it can. In this case, the horizontal and vertical bands are narrowed as the value of the parameter Q increases. As a result, as the value of the parameter Q increases, coefficient data for obtaining a high-resolution HD signal can be generated.

Further, the coefficient data generating device 150
The SD signal (525i) output from the signal generation circuit 152
Signal), the first to third tap selection circuits 15 for selectively extracting and outputting data of a plurality of SD pixels located around the target position in the HD signal (1050i signal).
3 to 155. These first to third tap selection circuits 153 to 155 correspond to the image signal processing unit 11 described above.
It has the same configuration as the first to third tap selection circuits 121 to 123 of 0.

Further, the coefficient data generation device 150
, A level distribution pattern of the data (SD pixel data) of the space class taps selectively extracted by the tap selection circuit 154, a space class is detected based on this level distribution pattern, and the space class for outputting the class information is output. It has a detection circuit 157. The space class detection circuit 157 has the same configuration as the space class detection circuit 124 of the image signal processing unit 110 described above. From this space class detection circuit 157, a requantization code qi for each SD pixel data as space class tap data is output as class information indicating a space class.

Further, the coefficient data generation device 150
The motion class detection circuit 158 detects a motion class mainly representing the degree of motion from the data (SD pixel data) of the motion class taps selectively extracted by the tap selection circuit 155, and outputs the class information MV. have. The motion class detection circuit 158 has the same configuration as the motion class detection circuit 125 of the image signal processing unit 110 described above. In the motion class detection circuit 158, an inter-frame difference is calculated from the data (SD pixel data) of the motion class tap selectively extracted by the third tap selection circuit 155, and the average of the absolute values of the differences is calculated. Then, a threshold value process is performed to detect a motion class that is a motion index.

Further, the coefficient data generation device 150 includes a re-quantization code qi as the class information of the space class output from the space class detection circuit 157 and the class information MV of the motion class output from the motion class detection circuit 158.
Class code CL indicating the class to which the pixel data of the target position in the HD signal (1050i signal) belongs based on
Has a class synthesis circuit 159 for obtaining The class synthesizing circuit 159 is also used for the image signal processing unit 11 described above.
The configuration is the same as that of the class synthesis circuit 126 of 0.

Further, the coefficient data generating device 150 outputs each HD pixel data y as pixel data of the target position obtained from the HD signal supplied to the input terminal 151 and each H pixel data y.
The data (SD pixel data) xi of the prediction tap selectively extracted by the first tap selection circuit 153 corresponding to each of the D pixel data y, and the output from the class synthesis circuit 159 corresponding to each HD pixel data y. From the class code CL to be used, n coefficient data w
It has a normal equation generator 160 for generating a normal equation (see equation (13)) for obtaining i.

In this case, the learning data described above is generated by a combination of one HD pixel data y and the corresponding n prediction tap pixel data. Therefore, the normal equation generating unit 160 registers a large amount of learning data. A normal equation is generated. Although not shown, a delay circuit for time alignment is arranged before the first tap selection circuit 153, so that the SD pixel data supplied from the first tap selection circuit 153 to the normal equation generation unit 160 is provided. The timing of xi is adjusted.

The coefficient data generating device 150 is supplied with the data of the normal equation generated for each class by the normal equation generating section 160, solves the normal equation generated for each class, and obtains the coefficient data wi of each class. And a coefficient memory 162 for storing the obtained coefficient data wi. In the coefficient data determination unit 161, the normal equation is solved by, for example, a sweeping-out method, and coefficient data wi is obtained.

The operation of the coefficient data generator 150 shown in FIG. 10 will be described. The input terminal 151 is supplied with an HD signal (1050i signal) as a teacher signal.
Horizontal and vertical thinning processing is performed on the D signal by the SD signal generation circuit 152 to generate an SD signal (525i signal) as a student signal. In this case, the parameter Q is supplied to the SD signal generation circuit 152 as a control signal, and a plurality of SD signals in which the horizontal and vertical bands change stepwise according to the discrete values of the parameter Q are sequentially generated. Will be done.

From this SD signal (525i signal), the second
The tap selection circuit 154 selectively extracts data (SD pixel data) of a space class tap located around the target position in the HD signal (1050i signal). The data (SD pixel data) of the space class tap selectively extracted by the second tap selection circuit 154 is supplied to the space class detection circuit 157. In the space class detection circuit 157, each SD pixel data as the data of the space class tap is subjected to the ADRC process, and the SD pixel data is re-created as the class information of the space class (mainly, the class classification for representing the waveform in the space). The quantization code qi is obtained (see equation (1)).

The third tap selection circuit 155 outputs the HD signal from the SD signal generated by the SD signal generation circuit 152.
Data (SD pixel data) of a motion class tap located around the target position in the signal is selectively extracted. The data (SD pixel data) of the motion class tap selectively extracted by the third tap selection circuit 155 is supplied to the motion class detection circuit 158. The motion class detection circuit 158 obtains the class information MV of the motion class (mainly a class classification for representing the degree of motion) from each SD pixel data as the data of the motion class tap.

The class information MV and the above-described requantization code qi are supplied to a class synthesis circuit 159. The class synthesis circuit 159 obtains a class code CL indicating the class to which the pixel data of the target position in the HD signal (1050i signal) belongs from the class information MV and the requantization code qi (see equation (3)). .

Further, the first tap selection circuit 153 outputs the HD signal from the SD signal generated by the SD signal generation circuit 152.
Data (SD pixel data) of a prediction tap located around the target pixel related to the signal is selectively extracted. Then, each HD pixel data y as pixel data of the target position obtained from the HD signal supplied to the input terminal 151,
The prediction tap data (SD pixel data) xi selectively extracted by the first tap selection circuit 121 corresponding to each of the HD pixel data y and each HD pixel data y
The normal equation generation unit 160 generates a normal equation for generating n pieces of coefficient data wi for each class from the class code CL output from the class synthesis circuit 159 corresponding to the above.

Then, the normal equation is solved in the coefficient data determination section 161 to obtain coefficient data wi of each class, and the coefficient data wi is stored in the coefficient memory 162 divided into addresses by class.

As described above, the coefficient data generating device 150 shown in FIG. 10 can generate the coefficient data wi of each class stored in the information memory bank 132 of the image signal processing section 110 of FIG. In this case, the SD signal generation circuit 1
The horizontal and vertical bands of the SD signal generated at 52 can be changed stepwise according to the value of the parameter Q. Therefore, the value of the parameter Q is set to 0, 1,.
, The coefficient data wi of each class corresponding to discrete values of 0, 1,..., 8 of the parameter Q can be generated.

Note that the processing in the image signal processing unit 110 in FIG. 1 can be realized by software, for example, by an image signal processing device 300 as shown in FIG.

First, the image signal processing device 30 shown in FIG.
0 will be described. This image signal processing device 300
A CPU 301 for controlling the operation of the entire apparatus, and the CPU 301
R storing the operation program and coefficient data 301
An OM (read only memory) 302 and a RAM (random access memory) 30 constituting a work area of the CPU 301
And 3. These CPU 301 and ROM 302
And the RAM 303 are connected to the bus 304.

The image signal processing device 300 includes a hard disk drive (HDD) 30 as an external storage device.
5 and a floppy (R) disk drive (FDD) 307 for driving a floppy (R) disk 306. These drives 305 and 307 are connected to the bus 304, respectively.

The image signal processing device 300 has a communication unit 308 that connects to a communication network 400 such as the Internet by wire or wirelessly. The communication unit 308 is connected to the bus 304 via the interface 309.

Further, the image signal processing device 300 includes a user interface unit. This user interface unit receives a remote control signal R from the remote control transmitter 200.
Remote control signal receiving circuit 310 for receiving M, LCD
(Liquid crystal display) 3
11 are provided. The receiving circuit 310 is connected to the bus 304 via the interface 312, and similarly, the display 311 is connected to the bus 304 via the interface 313.
It is connected to the.

Further, the image signal processing device 300 has an input terminal 314 for inputting an SD signal and an output terminal 315 for outputting an HD signal. Input terminal 3
14 is connected to the bus 304 via the interface 316, and similarly, the output terminal 315 is connected to the bus 304 via the interface 317.

Here, instead of storing the processing program and coefficient data in the ROM 302 in advance as described above, for example, the processing program and coefficient data are downloaded from the communication network 400 such as the Internet via the communication unit 308,
It can be stored in the AM 303 and used. In addition, these processing programs and coefficient data are stored on a floppy (R)
The information may be provided on the disk 306.

The SD signal to be processed is supplied to the input terminal 31.
Instead of inputting from the computer 4, the data may be recorded in a hard disk in advance or downloaded from the communication network 400 such as the Internet via the communication unit 308. Further, instead of outputting the processed HD signal to the output terminal 315 or in parallel with the output, the image signal is supplied to the display 311 for image display, further stored in the hard disk, or connected to the Internet or the like via the communication unit 308. You may make it transmit to the communication network 400.

Referring to the flowchart of FIG. 12, FIG.
A processing procedure for obtaining an HD signal from an SD signal in the image signal processing device 300 shown in FIG. 1 will be described. First, in step ST1, the process is started, and in step ST2, SD
Pixel data is input in units of fields. When the SD pixel data is input from the input terminal 314, the SD pixel data is temporarily stored in the RAM 303. If the SD pixel data is recorded on the hard disk, the S
The D pixel data is read out and temporarily stored in the RAM 303. Then, in step ST3, it is determined whether or not the processing of all the fields of the input SD pixel data has been completed. If the process has been completed, the process ends in step ST4. On the other hand, if the processing has not been completed, the process proceeds to step ST5.

In step ST5, the value of the parameter Q input by the user operating the remote control transmitter 200 is read from the RAM 303, for example. Then, step ST6
Then, the coefficient data of each class corresponding to two discrete values m, m + 1 (m = 0, 1,..., 7) located near the value of the read parameter Q is read and temporarily stored in the RAM 303. I do.

Next, in step ST7, in step ST2
The feature amount CH (√ (DR × ACT)) of each SD pixel is obtained from the SD pixel data for one field input in
Further, four characteristic amount regions Ra to Rd are determined using the characteristic amount CH of each SD pixel (see FIG. 6). In addition, each SD
The pixel feature amount CH is stored in the RAM 303 for further use in a later step.

Next, in step ST8, step ST2
The pixel data of the class tap and the prediction tap are obtained from the SD pixel data input in step (1) corresponding to each HD pixel data to be generated (target pixel data). Then, in step ST9, it is determined whether or not the process of obtaining HD pixel data has been completed in the entire area of the input SD pixel data. If the processing is not completed, step ST1
Go to 0.

In this step ST10, the S corresponding to each HD pixel data to be generated (pixel data at the position of interest).
The feature amount CH of the D pixel is equal to the four feature amount regions Ra to Ra described above.
It is detected which of Rd is included. Then, in step ST11, a coefficient selection signal SEL indicating which of the discrete values m and m + 1 is to be used for the coefficient data is generated from the detection information DET and the value of the parameter Q.

Next, in step ST12, step ST12 is executed.
A class code CL is generated from the SD pixel data of the class tap acquired in step 8. Then, in step 13, the coefficient data corresponding to the discrete value indicated by the coefficient selection signal SEL generated in step ST11,
Using the coefficient data of the class indicated by the class code CL generated in T12 and the SD pixel data of the prediction tap, the HD pixel data corresponding to the value of the parameter Q is calculated by the estimation formula (see formula (6)). After that, the process returns to step ST8 to repeat the same processing as described above.

If the process has been completed in step ST9, the process returns to step ST2 and shifts to the input process of the SD pixel data of the next field.

As described above, by processing according to the flowchart shown in FIG. 12, the input SD pixel data constituting the SD signal is processed, and the H pixel constituting the HD signal is processed.
D pixel data can be obtained. As described above, the HD signal obtained by such processing is output to the output terminal 315, supplied to the display 311 to display an image based on the HD signal, and further supplied to the hard disk drive 305 to be supplied to the hard disk drive 305. Or be recorded.

In the above-described embodiment, an example in which a linear linear equation is used as an estimation equation for generating an HD signal has been described. However, the present invention is not limited to this. May be used.

Further, in the above-described embodiment, an example in which the SD signal (525i signal) is converted to the HD signal (1050i signal) has been described. However, the present invention is not limited to this. Of course, the present invention can be similarly applied to other cases where the first image signal is converted into the second image signal.

[0140]

According to the present invention, when the first information signal is converted into the second information signal, the second information signal is converted to the second information signal by using the coefficient data corresponding to the parameter value indicating the resolution of the image. The pixel data at the target position is calculated, and the user can arbitrarily adjust the resolution of the image to a desired value by changing the value of the parameter. Further, according to the present invention, one coefficient data is selected from a plurality of coefficient data candidates corresponding to the parameter values and used by using a feature amount related to a high frequency component amount around the target position in the second image signal. Therefore, it is possible to prevent occurrence of a portion having an inappropriate resolution in an image based on the second image signal, and to improve image quality.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a television receiver as an embodiment.

FIG. 2 is a block diagram illustrating a configuration of a coefficient selection circuit.

FIG. 3 is a diagram provided for describing a dynamic range DR constituting a feature amount.

FIG. 4 is a diagram provided for explaining an activity ACT constituting a feature amount;

FIG. 5 is a diagram showing a model of a detection part of a dynamic range and an activity.

FIG. 6 is a diagram showing a histogram model of a feature amount corresponding to all SD pixels in one field.

FIG. 7 is a diagram illustrating an example of a location in each feature amount area and a degree of failure in a screen.

FIG. 8 is a diagram schematically illustrating resolution selection information in a ROM included in a coefficient selection signal generation unit.

FIG. 9 is a diagram for explaining a change in coefficient data used in each location on the screen with respect to a change in a value of a parameter Q indicating a resolution.

FIG. 10 is a block diagram illustrating a configuration of a coefficient data generation device.

FIG. 11 is a block diagram illustrating a configuration example of an image signal processing device realized by software.

FIG. 12 is a flowchart illustrating a procedure of image signal processing.

FIG. 13 is a diagram for explaining a pixel positional relationship between a 525i signal and a 1050i signal.

[Explanation of symbols]

100: television receiver, 101: system controller, 102: remote control signal receiving circuit, 105
... Reception antenna, 106 ... Tuner, 109
..Buffer memory, 110... Image signal processing unit, 1
11: display unit, 121: first tap selection circuit, 122: second tap selection circuit, 123
... third tap selection circuit, 124 ... space class detection circuit, 125 ... motion class detection circuit, 126
..Class synthesis circuits, 127 ... Estimation prediction calculation circuits,
128: post-processing circuit, 131: coefficient memory, 1
32: Information memory bank, 133: Coefficient selection circuit, 141: Feature amount detection unit, 142: Feature amount memory, 143: Feature amount area determination unit, 144: Area detection unit , 145... Coefficient selection signal generator, 150.
..Coefficient data generator 151, input terminal 15,
2 ... SD signal generation circuit, 153 ... first tap selection circuit, 154 ... second tap selection circuit, 155
... third tap selection circuit, 157 ... space class detection circuit, 158 ... motion class detection circuit, 159
..Class synthesis circuit, 160... Normal equation generator
161: coefficient data determination unit, 162: coefficient memory, 200: remote control transmitter, 300: image signal processing device, 301: CPU, 302: RO
M, 303: RAM, 304: Bus, 305
..Hard disk drive, 307 ... Floppy (R) disk drive, 308 ... Communication unit, 30
9, 312, 313, 316, 317 interface 310 remote control signal receiving circuit 311
・ Display, 314 ・ ・ ・ Input terminal, 315 ・ ・ ・
Output terminal, 400 ... communication network

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsumasa Obana 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Shinsuke Shintani 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo No. Sony Corporation F term (reference) 5C063 BA06 BA08 DA20 DB06 (54) [Title of the Invention] An image signal processing apparatus, an image signal processing method, an image display apparatus using the same, and each image signal processing method are described. Program to be executed and computer-readable medium recording the program

Claims (23)

[Claims] 1. An image signal processing device for converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data, wherein A first data selection unit that selects a plurality of first pixel data located around the target position in the second image signal; and a plurality of first pixel data selected by the first data selection unit. A feature amount detecting unit that detects a feature amount related to a high-frequency component amount around the target position; a resolution parameter output unit that outputs a parameter indicating a resolution of an image based on the second image signal; An image for generating pixel data of a target position in the second image signal according to the feature amount detected by the detection unit and the parameter output from the resolution parameter output unit. Image signal processing apparatus characterized by comprising a data generating means. 2. The coefficient data generating means for generating coefficient data candidates of an estimation formula for a plurality of representative resolutions corresponding to the parameters output from the resolution parameter output means, Resolution specifying means for specifying one of the plurality of representative resolutions based on the characteristic amount detected by the characteristic amount detecting means and the parameter output from the resolution parameter output means; Coefficient data selecting means for selecting coefficient data corresponding to the resolution specified by the resolution specifying means from coefficient data candidates generated by the means; and the second image signal based on the first image signal. A second data selection means for selecting a plurality of second pixel data located around the target position in the second data selection; Calculating means for calculating the pixel data at the target position based on the estimation formula, using the plurality of second pixel data selected by the means and the coefficient data selected by the coefficient data selecting means. The image signal processing device according to claim 1, wherein 3. The method according to claim 2, wherein the second image signal is generated based on the first image signal.
A third data selecting means for selecting a plurality of third pixel data located around the position of interest in the image signal of the above, based on the plurality of third pixel data selected by the third data selecting means Class coefficient detecting means for detecting a class to which the pixel data at the position of interest belongs, the coefficient data candidate generating means generating the coefficient data candidate for each class, and the coefficient data selecting means, 3. The coefficient data corresponding to the resolution specified by the resolution specifying means and the class detected by the class detecting means is selected from the coefficient data candidates generated by the data candidate generating means. 5. The image signal processing device according to claim 1. 4. The resolution specifying unit includes a feature amount detected by the feature amount detection unit among a plurality of feature amount regions determined based on the feature amount detected over the entire screen. Detecting means for detecting a feature amount area; storage means for storing resolution selection information in the plurality of feature amount areas corresponding to each value of the parameter; and parameters output from the resolution parameter output means from the storage means. And extracting means for retrieving the resolution selection information corresponding to the value and the feature amount area detected by the detection means, and specifying the one resolution based on the resolution selection information. The image signal processing device according to any one of the preceding claims. 5. The method according to claim 1, wherein the feature amount detecting unit uses the sum of absolute values of adjacent pixels in the plurality of first pixel data and a dynamic range in the plurality of first pixel data to calculate the high frequency. 2. The image signal processing apparatus according to claim 1, wherein a characteristic amount related to the component amount is obtained. 6. The image signal processing apparatus according to claim 1, wherein the resolution parameter output means generates a parameter indicating the resolution by a key input operation. 7. The image signal processing apparatus according to claim 1, wherein the resolution parameter output means generates a parameter indicating the resolution by rotating a knob. 8. An image signal input means for inputting a first image signal composed of a plurality of pixel data, and a second image signal composed of a plurality of pixel data, the first image signal being input from the image signal input means. Image signal processing means for converting the image signal into an image signal and outputting the image signal; image display means for displaying an image based on the second image signal output from the image signal processing means on an image display element; Resolution parameter output means for outputting a parameter indicating a resolution of an image, wherein the image signal processing means comprises: a plurality of second image signals located around a target position in the second image signal based on the first image signal; A first data selection unit for selecting one pixel data; and a plurality of first pixel data selected by the first data selection unit, the first and second pixel data in the vicinity of the target position. A feature value detecting means for detecting a feature value related to the frequency component value; and a second image signal corresponding to the feature value detected by the feature value detecting device and the parameter output from the resolution parameter output means. And a pixel data generating means for generating pixel data at a target position in the image display device. 9. The coefficient data candidate generating means for generating coefficient data candidates of an estimation formula for a plurality of representative resolutions corresponding to the parameters output from the resolution parameter output means, Resolution specifying means for specifying one of the plurality of representative resolutions based on the characteristic amount detected by the characteristic amount detecting means and the parameter output from the resolution parameter output means; Coefficient data selecting means for selecting coefficient data corresponding to the resolution specified by the resolution specifying means from coefficient data candidates generated by the means; and the second image signal based on the first image signal. A second data selection unit for selecting a plurality of second pixel data located around the target position in the second data selection; Calculating means for calculating the pixel data at the target position based on the estimation formula, using the plurality of second pixel data selected by the means and the coefficient data selected by the coefficient data selecting means. The image display device according to claim 8, wherein: 10. A third data selecting means for selecting a plurality of third pixel data located around a target position in the second image signal based on the first image signal, and Class detecting means for detecting a class to which the pixel data of the target position belongs based on the plurality of third pixel data selected by the data selecting means, wherein the coefficient data candidate generating means The coefficient data candidate is generated, and the coefficient data selection means is selected from among the coefficient data candidates generated by the coefficient data candidate generation means, and is detected by the resolution specified by the resolution specifying means and the class detection means. The image display device according to claim 9, wherein coefficient data corresponding to the class is selected. 11. The resolution specifying unit includes a feature amount detected by the feature amount detection unit among a plurality of feature amount regions determined based on the feature amount detected over the entire screen. Detecting means for detecting a feature amount area; storage means for storing resolution selection information in the plurality of feature amount areas corresponding to each value of the parameter; and parameters output from the resolution parameter output means from the storage means. And a specifying means for extracting the resolution selection information corresponding to the value of the characteristic amount and the feature amount area detected by the detection means, and specifying the one resolution based on the resolution selection information. The image display device as described in the above. 12. The method according to claim 11, wherein the characteristic amount detecting unit uses the sum of absolute values of adjacent pixels in the plurality of first pixel data and a dynamic range in the plurality of first pixel data to calculate the high frequency. 9. The image display device according to claim 8, wherein a characteristic amount related to the component amount is obtained. 13. The image display device according to claim 8, wherein the resolution parameter output means generates a parameter indicating the resolution by a key input operation. 14. The image display device according to claim 8, wherein the resolution parameter output means generates a parameter indicating the resolution by rotating a knob. 15. An image signal processing method for converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data, the method comprising: A first step of selecting a plurality of first pixel data located around the position of interest in the second image signal; and a step of selecting the plurality of first pixel data selected in the first step. A second step of detecting a feature amount related to a high-frequency component amount around the position; a third step of outputting a parameter indicating a resolution of an image based on the second image signal; and a detection step of the second step A fourth step of generating pixel data of a position of interest in the second image signal in accordance with the extracted feature amount and the parameter output in the third step.
And an image signal processing method. 16. The fourth step includes: generating candidate coefficient data of an estimation expression for a plurality of representative resolutions corresponding to the parameters output in the third step; and the second step Specifying one of the plurality of representative resolutions based on the feature amount detected in the above and the parameter output in the third step; and, from the generated coefficient data candidates, Selecting coefficient data corresponding to the specified resolution; and selecting a plurality of second pixel data located around a target position in the second image signal based on the first image signal. And calculating the pixel data at the target position based on the estimation formula using the selected plurality of second pixel data and the selected coefficient data. Image signal processing method according to claim 15, characterized in that a step. 17. A fifth step of selecting a plurality of third pixel data located around a position of interest in the second image signal based on the first image signal; And a sixth step of detecting a class to which the pixel data of the target position belongs based on the selected plurality of third pixel data. In the step of generating the coefficient data candidates, 17. The method according to claim 16, wherein the step of generating coefficient data candidates and selecting the coefficient data selects coefficient data corresponding to the specified resolution and the class detected in the sixth step. Image signal processing method. 18. The step of specifying the resolution includes a feature amount detected in the second step from a plurality of feature amount regions determined based on the feature amount detected over the entire screen. From the memory storing resolution selection information in the plurality of feature amount areas corresponding to each value of the parameter and the value of the parameter output in the third step and the detected feature. The resolution selection information corresponding to the quantity area is extracted, and thereafter, one of the plurality of representative resolutions is specified based on the extracted resolution selection information. Image signal processing method. 19. The method according to claim 19, wherein the second step uses the sum of absolute values of adjacent pixels in the plurality of first pixel data and the dynamic range in the plurality of first pixel data to calculate the high frequency. 16. The image signal processing method according to claim 15, wherein a characteristic amount related to the component amount is obtained. 20. The image signal processing method according to claim 15, wherein in the third step, a parameter indicating the resolution is generated by a key input operation. 21. The image signal processing method according to claim 15, wherein in the third step, a parameter indicating the resolution is generated by rotating a knob. 22. A method for converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data, comprising the steps of: A first step of selecting a plurality of first pixel data located in the vicinity of the target position; and a high frequency in the vicinity of the target position based on the plurality of first pixel data selected in the first step. A second step of detecting a feature amount related to the component amount, a third step of outputting a parameter indicating a resolution of an image based on the second image signal, and a feature amount detected in the second step. A fourth step of generating pixel data of a target position in the second image signal in accordance with the parameter output in the third step.
And a computer-readable medium storing a program for causing a computer to execute the image signal processing method having the steps of: 23. A method for converting a first image signal composed of a plurality of pixel data into a second image signal composed of a plurality of pixel data, comprising the steps of: A first step of selecting a plurality of first pixel data located in the vicinity of the target position; and a high frequency in the vicinity of the target position based on the plurality of first pixel data selected in the first step. A second step of detecting a feature amount related to the component amount, a third step of outputting a parameter indicating a resolution of an image based on the second image signal, and a feature amount detected in the second step. A fourth step of generating pixel data of a pixel of interest in the second image signal in accordance with the parameter output in the third step.
For causing a computer to execute the image signal processing method having the steps of: