JPH099050A - Picture processor - Google Patents

Abstract

PURPOSE: To precisely judge a picture type by deciding the picture type of a judgement area which is set from first judgement feature quantity of a judgement area which is set from first judgement feature feature quantity by means of a second calculation means. CONSTITUTION: A synchronizing signal is inputting to a counter reset circuit 160 from SSG11, and the judgement area is set in a prescribed area in a screen. A change quantity detection circuit 110 obtains the change quantity S1 and the average value S2 of picture element data in a change quantity detection area from input picture data S0. In a picture judgement circuit 15, counter circuits 121b and 122b execute a count operation and output count values N1 and N2 based on the frequency information of the change quantity S1 when the judgement outputs S4 and S5 of judgement circuits 121a and 122a are H and S7 is H. In the circuit 15, the edge part of the picture in the change quantity detection area is detected and frequency information of picture element data constituting an edge is obtained as the number N3 of the area whose average value S2 is larger than a threshold S3. CPU14 judges the picture type by using the count values N1, N2 and N3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus for determining what kind of image the input or generated image data belongs to.

[0002]

2. Description of the Related Art Generally, images are roughly classified into the following: Images with high contrast such as document images and line drawings. It can be classified into an image having gradation such as a natural image.

When such an image is subjected to processing such as binarization and compression, a processing method suitable for each image type, that is, for each image type. Therefore, it is necessary to determine this image type in advance.

Conventionally, such a method for determining the type of image has been performed by paying attention to the spatial variation of pixel data.

A conventional determination example will be described below with reference to FIGS. 26 and 27.

FIG. 26 and FIG. 27 are diagrams showing the frequency of the amount of change in pixel data. The horizontal axis represents the amount of change in pixel data, and the amount of change increases toward the right in the figures. Shows. The vertical axis shows the frequency.

For example, in a document image, as shown in FIG. 26, there is a tendency that there are many pixels with a large amount of change in pixel data. On the other hand, as shown in FIG. 27, in a natural image, the amount of change in pixel data tends to take various values.

[0008]

However, in the above-described conventional determination method, there is a risk of making an erroneous determination depending on the image. An example of an image that may cause this erroneous determination will be shown below.

1. Document image with low contrast For example, a document image in which characters are written on a colored background, or conversely, a document image with colored characters. Although such an image is a document image, there are few pixels in which the amount of change in pixel data is large.

[0010] 2. High-contrast picture images For example, posters and animated images are available. Although such an image is a natural image, few pixels have a small amount of change in pixel data.

Therefore, the above-mentioned image may be erroneously judged when judged by the conventional method. As a result,
For example, there is a problem that the processing method such as the binarization processing and the compression processing is wrong.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image processing apparatus capable of accurately determining the type of image as described above, that is, the image type.

[0013]

In order to achieve the above object, the first image processing apparatus according to the present invention has a determination area for setting a determination area for determining the type of an image in a predetermined area on the screen. Setting means and the change amount detection area set in the screen while moving the change amount detection area to detect the change amount of the pixel data so as to cover the corresponding portion on the determination area. A change amount detection unit that sequentially obtains a change amount of pixel data, and a first determination feature amount that is obtained based on frequency information within the determination region for each change amount detected by the change amount detection unit. Computing means,
Based on the edge portion detection means for detecting the edge portion of the image in the change amount detection area, and the frequency information in the determination area for the pixel data of the pixel group forming the edge portion detected by the edge portion detection means. At least the setting is made from the second calculation means for obtaining the second judgment feature quantity, the first judgment feature quantity by the first calculation means, and the second judgment feature quantity by the second calculation means. And an image type determining means for determining the type of image in the determination area.

In order to achieve the above object, a second image processing apparatus according to the present invention is the first image processing apparatus, wherein the first image processing apparatus is suitable for compressing natural image data. The second suitable for compressing character image data
Data compression means, and adaptively selects the first or second data compression means in accordance with the output of the image type determination means, and performs data compression processing of at least the set determination area. Means are provided.

To achieve the above object, a third image processing apparatus according to the present invention is the second image processing apparatus, wherein the first data compression means and / or the second data compression means is an image processing apparatus. It is characterized in that the binarization process of is performed.

In order to achieve the above object, a fourth image processing apparatus according to the present invention is the same as the first image processing apparatus, wherein the change amount detecting means has a change amount detection area and a size of the determination area. However, it is characterized in that it is set so as to be included in the screen regardless of the above.

To achieve the above object, a fifth image processing apparatus according to the present invention is characterized in that, in the first image processing apparatus, the judgment area setting means variably sets the judgment area. And

To achieve the above object, a sixth image processing apparatus according to the present invention is the first image processing apparatus according to the first image processing apparatus, wherein the determination area setting means can set a plurality of determination areas. It is characterized by being a thing.

To achieve the above object, a seventh image processing apparatus according to the present invention is the sixth image processing apparatus, wherein in the sixth image processing apparatus, the first and second determinations are made in correspondence with the plurality of determination areas set. It is characterized in that it further comprises means for weighting the frequency information for calculating the characteristic amount.

To achieve the above object, an eighth image processing apparatus according to the present invention is the same as the first image processing apparatus, wherein the change amount detecting means changes the change amount of the change amount detection area by the change amount. It is characterized by comprising means for normalizing with average pixel data in the quantity detection region.

To achieve the above object, a ninth image processing apparatus according to the present invention is the first image processing apparatus according to the first image processing apparatus, wherein the change amount detecting means has m ×
A rectangular area of n (m, n is an arbitrary natural number) pixels is used, and the change amount of the pixel data is detected using the pixel data of at least a corner portion of the change amount detection area. Characterize.

To achieve the above object, a tenth image processing apparatus according to the present invention is the first image processing apparatus, wherein the first arithmetic means is the pixel data obtained by the change amount detecting means. Change amount is determined by two different conditions, the number of change amount detection regions to which pixel data satisfying the condition is counted for each condition, and the ratio of each count value is set as the first determination feature amount. It is characterized by being made.

To achieve the above object, an eleventh image processing device according to the present invention is the tenth image processing device, wherein the first computing means is the pixel data obtained by the change amount detecting means. It is characterized in that the number of change amount detection areas to which the pixel data whose change amount is less than a predetermined value belongs is excluded from the count value.

To achieve the above object, a twelfth image processing device according to the present invention is the same as the tenth image processing device, wherein the edge portion detecting means is the pixel data obtained by the change amount detecting means. It is characterized in that the edge portion is detected under either one of two different conditions for judging the amount of change.

To achieve the above object, a thirteenth image processing apparatus according to the present invention is the first image processing apparatus according to the first image processing apparatus, wherein the second computing means has a predetermined average pixel data within a change amount detection area. It is characterized in that the ratio of the number of change amount detection areas larger or smaller than the value of and the number of change amount detection areas including the edge portion is set as the second determination feature amount. .

In order to achieve the above-mentioned object, a fourteenth image processing apparatus according to the present invention is the first image processing apparatus described above, which includes at least means for generating image data of the set judgment area, It is characterized by comprising means for performing a focusing operation or an exposure control operation prior to the determination of the type.

To achieve the above object, a fifteenth image processing apparatus according to the present invention is the same as the first image processing apparatus, but includes at least means for generating image data of the set judgment area, and the exposure condition is satisfied. It is characterized in that means is provided for varying the conditions for obtaining the first and second determination feature quantities according to the above.

In order to achieve the above-mentioned object, a sixteenth image processing apparatus according to the present invention is the first image processing apparatus of the above-mentioned first image processing apparatus, which includes at least a means for generating image data of the set judgment area. Is provided, and means for determining the type of the image by taking the data into consideration is provided.

To achieve the above object, a seventeenth image processing apparatus according to the present invention is the image processing apparatus according to the sixteenth image processing apparatus, wherein the means for determining the type of the image is data of a pixel in a light shielding state. Is obtained by detecting the differential change amount in the period of N fields (N is an arbitrary natural number) and obtaining the maximum differential change amount level in this N field period, which is used when determining the image type. It is characterized in that it is configured as follows.

To achieve the above object, an eighteenth image processing device according to the present invention is the sixteenth image processing device, wherein the means for generating the image data is composed of an amplification type image pickup device. It is characterized in that it is provided with means for allowing the image after removing the fixed pattern noise generated by using the amplification type image pickup element to be used for the determination of the type of the image.

To achieve the above object, a nineteenth image processing device according to the present invention is the sixteenth image processing device, wherein the means for generating the image data is composed of an amplification type image pickup device. It is characterized in that a means is provided for making the differential change amount of the fixed pattern noise corresponding to the pixel of (3) available for the determination of the type of the image.

In order to achieve the above-mentioned object, a twentieth image processing apparatus according to the present invention is an image processing apparatus for determining the type of an image taken in from an optical system, when the image is optically shielded. It is characterized in that it comprises a light-shielding state signal component obtaining means for obtaining an image signal component, and means for determining the type of image in consideration of the signal component from the light-shielding state signal component obtaining means.

To achieve the above object, a twenty-first image processing apparatus according to the present invention is the twentieth image processing apparatus, wherein the light-shielding state signal component acquisition means is a differential change amount detection means for a period of n fields. It is characterized in that the maximum differential change amount in the n-field period is acquired and is used when determining the image type.

To achieve the above object, a twenty-second image processing apparatus according to the present invention is the image processing apparatus according to the twentieth aspect, wherein the optical system includes an amplification type solid-state image pickup element, and the amplification type solid-state image pickup element is provided. It is characterized in that it is provided with a means for judging the type of the image after removing the fixed pattern noise generated by the use.

To achieve the above object, a twenty-third image processing apparatus according to the present invention is the twentieth image processing apparatus, wherein the optical system includes an amplification type solid-state image pickup device, and each of the fixed pattern noises is different from each other. It is characterized in that a fixed pattern noise edge corresponding to a pixel is used when determining the type of an image.

[0036]

In the first image processing apparatus according to the present invention, the judgment area setting means sets a judgment area for judging the image type in a predetermined area in the screen. Further, the change amount is detected by moving the change amount detection area, which is set in the screen by the change amount detecting means and is a target for detecting the change amount of the pixel data, so as to cover the corresponding portion on the determination area. The amount of change in pixel data in the detection area is sequentially obtained. Then, the first determination feature amount is obtained by the first calculation device based on the frequency information in the determination region for each change amount detected by the change amount detection device. Further, the edge portion detection means detects the edge portion of the image in the change amount detection area, and the frequency information in the determination area for the pixel data of the pixel group forming the edge portion detected by the edge portion detection means is used. Based on this, the second determination feature amount is obtained by the second calculation means. Then, the image type determining unit determines at least the image type of the set determination region from the first determination feature amount by the first computing unit and the second determination feature amount by the second computing unit. decide.

According to a second image processing apparatus of the present invention, in the first image processing apparatus, the first or second data compression means is adaptively selected according to the output of the image type determination means. , At least the data compression processing of the set determination area is performed.

A third image processing apparatus according to the present invention is the same as the second image processing apparatus, wherein the first data compression means and / or the second data compression means performs image binarization processing.

According to a fourth image processing apparatus of the present invention, in the first image processing apparatus, the change amount detecting means is
The change amount detection area is set to be included in the screen regardless of the size of the determination area.

According to a fifth image processing apparatus of the present invention, in the first image processing apparatus, the judgment area setting means variably sets the judgment area.

According to a sixth image processing apparatus of the present invention, in the first image processing apparatus, the judgment area setting means can set a plurality of judgment areas.

A seventh image processing apparatus according to the present invention is, in the sixth image processing apparatus, for calculating the first and second determination feature amounts corresponding to the plurality of determination areas set. The frequency information is weighted.

An eighth image processing apparatus according to the present invention is the same as the first image processing apparatus, wherein the change amount detecting means is
The change amount of the change amount detection area is normalized by the average pixel data in the change amount detection area.

According to a ninth image processing apparatus of the present invention, in the first image processing apparatus, the change amount detecting means is
The change amount detection area is m × n (m and n are arbitrary natural numbers)
The amount of change in pixel data is detected using the pixel data in at least the corners of the change amount detection region as a rectangular region of pixels.

A tenth image processing apparatus according to the present invention is the first image processing apparatus according to the first image processing apparatus, wherein the first computing means has two conditions that differ in the variation amount of the pixel data obtained by the variation amount detecting means. The number of change amount detection regions to which the pixel data satisfying the condition belongs is counted for each condition, and the ratio of each count value is set as the first determination feature amount.

An eleventh image processing apparatus according to the present invention is the tenth image processing apparatus, wherein the first computing means sets the variation amount of the pixel data obtained by the variation amount detecting means to a predetermined value. The number of change amount detection regions to which the pixel data that does not belong is excluded from the count value.

A twelfth image processing device according to the present invention is the same as the tenth image processing device, wherein the edge portion detecting means determines two different amounts of pixel data obtained by the change amount detecting means. The edge portion is detected according to either one of the conditions.

A thirteenth image processing apparatus according to the present invention is the first image processing apparatus according to the first image processing apparatus, wherein the second arithmetic means has average pixel data within a change amount detection area larger or smaller than a predetermined value. The ratio of the number of change amount detection areas and the number of change amount detection areas including the edge portion is set as the second determination feature amount.

A fourteenth image processing apparatus according to the present invention is the same as the first image processing apparatus described above, including at least means for generating image data of the set judgment area, and focusing prior to the determination of the image type. Take action or exposure control action.

A fifteenth image processing apparatus according to the present invention is the first image processing apparatus of the first aspect, further including at least means for generating image data of the set judgment area, and the first and first image processing apparatuses according to exposure conditions. The condition for obtaining the determination feature amount of 2 is changed.

A sixteenth image processing apparatus according to the present invention is the same as the first image processing apparatus, but includes at least means for generating image data of the set judgment area, and obtains data of pixels in a light-shielded state. The image type is determined in consideration of this data.

In a seventeenth image processing apparatus according to the present invention, in the sixteenth image processing apparatus, the means for determining the type of the image is N fields (for obtaining data of pixels in a light-shielded state). N is an arbitrary natural number) The differential change amount in the period is detected to obtain the maximum differential change amount level in this N field period,
Used when determining the image type.

An eighteenth image processing apparatus according to the present invention is the same as the sixteenth image processing apparatus, wherein the image after removing the fixed pattern noise generated by using the amplification type image pickup device is used for determining the image type. Offer.

The nineteenth image processing apparatus according to the present invention is, in the sixteenth image processing apparatus, provided with the differential change amount of the fixed pattern noise corresponding to each pixel for determining the image type.

In the twentieth image processing apparatus according to the present invention, the light-shielded state signal component acquisition means obtains an image signal component in an optically light-shielded state, and the signal component from the light-shielded state signal component acquisition means is considered. Determine the type of image.

A twenty-first image processing apparatus according to the present invention is the twentieth image processing apparatus, wherein the light-shielding state signal component acquiring means includes a differential change amount detecting means for an n-field period, and in the n-field period. The maximum differential change amount is acquired and used when determining the image type.

A twenty-second image processing apparatus according to the present invention is the image processing apparatus according to the twentieth image processing apparatus, wherein the fixed pattern noise generated by using the amplification type solid-state imaging device is removed from the image. Determine the type.

The twenty-third image processing apparatus according to the present invention uses the fixed pattern noise edge corresponding to each pixel from the above fixed pattern noise in the above twentieth image processing apparatus when determining the type of the image.

[0059]

Embodiments of the present invention will be described below with reference to the drawings.

First, an embodiment corresponding to claims 1 to 3 and claims 8 to 15 will be described.

FIG. 1 is a block diagram showing the schematic arrangement of an image processing apparatus according to the first embodiment of the present invention.

This image processing apparatus comprises a photographing optical system 1 having an optical lens and a diaphragm. Various control signals are input to the photographing optical system 1 from a CPU 14 described later and controlled. Further, behind the photographing optical system 1, an image pickup section including a shutter 1a as a mechanical light shielding means and an image pickup element such as a CCD 2 is provided. Then, a subject image is formed on the image pickup device such as the CCD 2 using the optical lens, the diaphragm, and the shutter 1a. The configuration of the image processing apparatus according to the present embodiment other than that described above will be described below along the flow of signals.

The image signal based on the subject photoelectrically converted by the CCD 2 is input to the process circuit 3, and the process circuit 3 performs various processes on the image signal. On the other hand, a signal for controlling the driving of the CCD 2 is given to the CCD 2 from a timing generator 10 (shown as TG in the figure). Further, a timing pulse for performing CDS (Double Correlation Sampling) or clamp processing is input from the timing generator 10 to the process circuit 3.

Further, a control signal for defining an electronic shutter speed is sent from the CPU 14 to the timing generator 10.

The image signal processed by the process circuit 3 is input to the A / D converter 4 (indicated as A / DC in the figure), and the A / D converter 4 converts the analog signal into a digital multi-gradation image. It is converted into a data signal S0.

The image data signal S0 output from the A / D converter 4 is input to the main memory 5, and the image determining circuit 15 for determining the image type and the control for exposure and focusing during photographing are performed. It is input to the exposure / focus control unit 13 (indicated as AE / AF in the figure) for performing.

The image determination circuit 15 corresponds to claim 1. Details will be described later.

The image data S0 input to the main memory 5 is converted into non-interlaced image data by the memory controller 12 and input to the simple binarization circuit 6 and the pseudo halftone processing circuit 7.

The simple binarization circuit 6 and the pseudo halftone processing circuit 7 correspond to claims 2 and 3.

The signal binarized in the simple binarization circuit 6 and the pseudo halftone processing circuit 7 is input to the switch 8 and selectively output from the switch 8 according to the image type determination result described later. It That is, when the input image is determined to be a natural image, the binarized signal is selected in the pseudo halftone processing circuit 7, and when the input image is determined to be a document image, the simple 2 The binarization circuit 6 selects and outputs the binarized signal. further,
When outputting to a storage device such as a memory, the compression circuit 9 compresses the data amount of the signal output from the switch 8. Further, when outputting to a display device such as a printer, the compression circuit 9 does not perform the compression operation and outputs the signal output from the switch 8 as it is.

For the signal binarized in the compression circuit 9, a compression method such as MH coding or MR coding adopted in a facsimile or the like can be used. Further, with respect to the signal which has been subjected to the pseudo halftone processing, the amount of data may rather increase when the above-mentioned encoding is performed. Therefore, whether or not the above-mentioned encoding is performed is arbitrarily selected and performed.

Further, in the present embodiment, since the multi-gradation data input by the binarization processing is converted into 1-bit data, the pseudo halftone processing circuit 7 and the character are used as the data compression means for the natural image. The simple binarization circuit 6 may be used as data compression means for each image.

Next, the automatic exposure control operation (AE) and the automatic focusing control operation (AF) in this embodiment will be described.

In the AE / AF block 13 shown in FIG. 1, the image data S0 output from the A / D converter 4 is divided into a plurality of areas as shown in FIG. 13, and the average pixel data is calculated for each area. The average value and contrast value are calculated. The CPU 14 controls the aperture of the photographing optical system 1, the electronic shutter speed of the timing generator 10 and the amplification degree of the process circuit 3 so that the average value of the pixel data obtained by the AE / AF block 13 becomes a predetermined value. To perform AE. Further, the CPU 14 performs AF by controlling the position of the focus adjustment lens of the photographing optical system 1 so that the average value of the contrast values obtained by the AE / AF block 13 becomes maximum.

The image processing apparatus of this embodiment, as shown in FIG. 1, is a sync signal generation circuit (S) for generating a predetermined sync signal.
SG) 11, and a timing generator 10 and a main memory 5 for driving the CCD 2 according to a predetermined synchronizing signal generated in the SSG 11.
The memory controller 12 for controlling the memory is operated.

Further, similarly, the image determination circuit 15 determines the A based on the synchronization signal output from the SSG 11.
The image determination operation is performed in synchronization with the image data signal S0 which is the output signal from the / D converter 4. Further, the CPU 14 outputs the image determination result of the image determination circuit 15 and inputs a control signal used for the determination.

FIG. 3 is a block diagram showing the configuration of the image determination circuit and its peripheral portions, the SSG and the CPU, in the first embodiment.

That is, the HD signal, the FLD signal, and the VD signal are input from the SSG 11 to the image determination circuit 15, and these synchronization signals are received by the counter reset circuit 160 as the determination area setting means. Has become. The counter reset circuit 160 will be described later in detail. The counter reset circuit 160 corresponds to the determination area setting means according to claim 1.

Here, the HD signal is a horizontal synchronizing signal which is used in a television or the like and which indicates the driving timing in the horizontal direction, and the FLD signal is whether the interlaced screen of the television is an even screen or an odd screen. Is a signal indicating. Further, the VD signal is a vertical synchronization signal representing one screen used in television and the like.

In the image determination circuit 15, the image data S0 output from the A / D converter 4 is first input to the change amount detection circuit 110. In the change amount detection circuit 110, the change amount S1 and the average value S2 of the pixel data in the change amount detection area are obtained. In this embodiment, as shown in FIG.
The region of × 3 is used as the change amount detection region, and the change amount S1 of the pixel E in the change amount detection region is set as the pixels A to C corresponding to the four corners of the change amount detection region. Then, the difference between the maximum brightness data and the minimum brightness data is obtained. Further, as the average value S2, the average value of the pixels A, C, G, and I corresponding to the four corners of the change amount detection area among the pixels A to I is obtained. By doing so, an arithmetic circuit for obtaining the change amount S1 and the average value S2 can be realized with a simple configuration, and as shown in FIG. 6, the image data S0 input as an interlace signal and the delay circuit 140 are delayed by one line time. Necessary pixel data can be obtained from the image data S0. Therefore, the circuit can be downsized and the calculation time can be shortened.

FIG. 5 shows the configuration of the circuit for obtaining the change amount S1 and the average value S2 in this embodiment. The circuit indicated by T in FIG. 5 is a delay circuit having a function of delaying input image data by one pixel time. Therefore, the alphabet attached to the output of each delay circuit in FIG. 5 corresponds to the pixels A to I shown in FIG.

First, a method of calculating the variation S1 will be described. The data of the pixel C and the pixel I is input to the size determination circuit 150. The magnitude determination circuit 150 includes a comparator and two selectors. For example, when pixel C <pixel I, the output of the comparator is “L”, and the pixel I is output from the MAX selector.
The pixel C is output from the min selector. See also MAX
The data obtained by delaying the outputs of the selector and the min selector by 2 pixels respectively and the data not delayed are input to the size determination circuit 151 and the size determination circuit 152 having the same configuration as the size determination circuit 150, respectively. MAX selector, mi
The data obtained by delaying each output of the n-selector by two pixels is the large data or the small data of the pixel A and the pixel G. Therefore, the output signal of the MAX selector of the size determination circuit 151 becomes the maximum luminance data in the pixels A, C, G, I, and the output signal of the min selector of the size determination circuit 152 is in the pixels A, C, G, I. Is the minimum brightness data. Finally, the change amount S1 can be calculated by obtaining the difference between the output signal of the MAX selector of the magnitude determination circuit 151 and the output signal of the min selector of the magnitude determination circuit 152.

Next, a method of calculating the average value S2 will be described.
As can be seen from the alphabet attached to the output of each delay circuit in FIG. 5, the average value S2 can be calculated by obtaining the sum of the pixels A, C, G and I and dividing by the number of pixels 4.

In the image judging circuit 15, the change amount detecting circuit 1
It is necessary to obtain the frequency information in the determination area of the change amount S1 of the pixel data in the change amount detection area obtained in 10. In this embodiment, first, the variation amount S1 of the pixel data in the variation amount detection area is normalized by the average value S2 of the pixel data.
Then, the frequency information in the determination area of the amount of change in the normalized pixel data is used to detect the amount of change in which the amount of change in the normalized pixel data is greater than two threshold values K1 and K2 (where K1 ≦ K2). It is obtained by counting the number of regions in each determination region.

In the present embodiment, the decision circuits 121a,
When the average value S2 of the pixel data is multiplied by a threshold value Ki (i = 1, 2) and the variation amount S1 of the pixel data is compared as shown in FIG. 8 as 122a, S1 ≧ S2 × Ki is satisfied. A signal of "H" is output to. Further, by adding the lower limit values b1 and b2 (b1 ≦ b2) to the determination condition, erroneous detection due to noise can be prevented.

Next, the counter circuits 121b and 122b are provided with the determination circuits 121a and 122a, respectively, as shown in FIG.
When the determination outputs S4 and S5 of "1" are "H" and S7 is "H", the counting operation is performed. Here, S7 is a signal representing the determination area, and a signal of "H" is input in the determination area. The CLEAR signal is a signal for controlling the operation of the counter circuit and operates the counter circuit only when the image determination circuit 15 is operating.

Further, the counter circuits 121b and 122
The values N1 and N2 counted in b are temporarily stored in the register 121.
c, 122c. The count values N1 and N2 are
The CPU 14 can read the data as appropriate.

The lower limit values b1 and b2 may be varied according to the amplification degree of the process circuit 3. Generally, noise included in a signal output from an image pickup device such as a CCD depends on charges accumulated in a photoelectric conversion unit. Therefore, the lower limit values b1 and b2 may be fixed values for a subject whose light quantity can be controlled to a substantially constant amount by controlling the aperture of the photographing optical system 1 or electronic shutter control by the timing generator 10, but increase the amplification degree of the process circuit 3 for a dark subject. The noise amount increases, and the lower limit values b1 and b2 are increased accordingly.

Further, the image judgment circuit 15 needs to detect the edge part of the image in the change amount detection area and to obtain the frequency information in the judgment area of the pixel data of the pixel group forming the edge part.

In this embodiment, first, the change amount detection area having the change amount of pixel data such that the output of the determination circuit 121a becomes "H" is set as the edge portion of the image. Further, the average value S2 of the pixel data in the change amount detection area is used as the pixel data of the pixel group forming the edge portion. Further, the frequency information in the determination area of the pixel data of the pixel group forming the edge portion is used to determine the number of change amount detection areas in which the average value S2 of the pixel data in the change amount detection area is larger than the threshold value S3. It is obtained by counting over. That is, the number N3 of change amount detection areas in which the average value S2 of the pixel data in the change amount detection areas determined to be the edge portion of the image is larger than the threshold value S3 is obtained.

As shown in FIG. 10, the average value circuit 130
Means that the image data S0 is input to the adder circuit only while the signal S7 representing the judgment region is “H”, the output of the adder circuit is connected to the other input of the adder circuit through the delay circuit T, and It is divided by the number M of change amount detection areas. By doing so, the average value of the pixel data in the determination area is output as the threshold value S3.

Further, the average value S of the pixel data in the change amount detection area output from the change amount detection circuit 110 is output.
2, the comparison circuit 123a performs a comparison operation with the output signal S3 of the average value circuit 130, and when the average value S2 ≧ S3, “H” is output. Further, by taking the AND of the output signal S4 of the determination circuit 121a and the output signal of the comparison circuit 123a, the average value S2 of the pixel data in the change amount detection area determined to be the edge portion of the image is larger than the threshold value S3. A signal S6 indicating the change amount detection area is obtained.

Next, the counter circuit 123b performs a counting operation when the signal S6 is "H" and S7 is "H" as shown in FIG. Here, S7 is a signal representing the determination area, and a signal of "H" is input in the determination area.
The CLEAR signal is a signal for controlling the operation of the counter circuit and operates the counter circuit only when the image determination circuit 15 is operating.

Further, the value N3 counted by the counter circuit 123b is once transferred to the register 123c.
The count value N3 can be read by the CPU 14 as appropriate.

Next, the operations of the comparison circuit 123a and the determination circuit 121a will be briefly described with reference to FIG.

In FIG. 25, the signal shown by the solid line represents the input signal S0, and the horizontal axis represents the passage of time or the place on the screen. On the other hand, the vertical axis represents the brightness of the image, with the upper one being bright and the lower one being dark.

On the other hand, the change amount detecting circuit 110
The average value signal S2 obtained in step S1 changes as shown by the dotted line in FIG.

Further, regarding the change amount signal S1 obtained by the change amount detection circuit 110, a waveform as shown by the solid line below is output.

When this is judged by the judging circuit 121a, a judgment result that the peak portion shown in FIG. 25 includes an edge is obtained. Therefore, the average value signal S2 shown by the broken line for that portion is obtained, This is compared with the average value signal S3.

Since the average value signal S3 is the average value of the image data in the judgment area, it shows a value slightly lower than the bright peak portion as shown by the solid line in FIG.

Therefore, as the output of the signal S6, the value of the average value signal S2 at the point of interest is lower than that of the average value signal S3, so that the output of the signal S6 is always at the "L" level. It is suitable for detecting black characters on a white plate.

On the contrary, when the input data shown by the solid line has a peak in the opposite direction, the value of the average value signal S2 becomes larger than the average value signal S3. In this case, therefore, the signal S6 is " The H level is reached, and the counter circuit 123b performs a counting operation, which is suitable for detecting, for example, white characters on a blackboard.

Next, the operation of the image type determining circuit will be described.

This image type determining circuit is formed inside the CPU 14 in the present embodiment, and the registers 121c and 122 are used as data used for determination.
c, 123c output count values N1, N2, N
3 is used.

11 and 12 are explanatory views showing an example of the determination method in the image type determination circuit. Note that FIG.
1, the horizontal axis represents the value obtained by dividing N3 by N1, and the vertical axis represents the value obtained by dividing N2 by N1.

As described in the conventional example, FIG. 26 shows the frequency distribution of the variation amount of pixel data, and generally, in a document image, the frequency of pixels having a large variation amount of pixel data is high. In addition, as shown in FIG. 27, in the natural image, there is a tendency that the amount of change in pixel data is small but the frequency is high.

Therefore, the result of counting by setting a relatively high threshold level for each,
As a result of counting by setting a relatively low threshold level, that is, N2 and N1 are obtained, for an image type in which pixels with a large amount of change have a high frequency such as a document image, N2 divided by N1 is a large value. 27, and conversely, for a natural image as shown in FIG.
Those divided by tend to show relatively small values.

Therefore, on the vertical axis in FIG. 11, the closer the value is to “1”, the higher the possibility of being a document image, and the closer to “0”, the higher the possibility of being a natural image. In addition, about the horizontal axis, as shown in FIG.
When you look at the brightness values of the pixels in the part that contains the edges, you can see the frequency distribution for all brightness values for natural images, while for a document image on a white background, the distribution is biased toward the darker side. On the contrary, in the case of a black document image, the luminance distribution tends to be higher.

Therefore, when viewed with reference to the average value S3 of the entire screen in the determination area, the average value of the luminance of the pixels including the edge is larger or smaller than the average value of the entire screen in the natural image. Have a substantially uniform distribution, whereas a white document has a small value, that is, a large distribution in the lower part, and a black document image tends to have a value close to 1, that is, a large value. With.

Therefore, in FIG. 11, the portion near the horizontal axis "0" is likely to be a white background document, and the one near "1" is likely to be a black background document image. Also, if it is in the center, it is highly likely that it is a natural image.

Therefore, the two judgment feature quantities are calculated as shown in FIG.
Plotted on a two-dimensional graph as shown in 1, and finally determined depending on which of the three types of areas, that is, a white background document, a black background document, and a natural image belongs to. It is carried out.

The counter values N1 and N2, N
Regarding the operation of division by 3, in this embodiment, CP
It is done in the circuit of U14.

Similarly, as shown in FIG. 12, by providing a convex area, the shape can be modified so that a simpler determination can be performed.

Next, the timing of the above image type determination in the image processing apparatus of this embodiment will be described with reference to FIG.

First, in the first field, the average value circuit 130 in the image determination circuit 15 calculates S3. Next, in the second field, the image determination circuit 15
The count values N1, N2, N3 are obtained at. Next, in the third field, the CPU 14 determines the image type. Then, in the fourth field, the signal S9 indicating the image type is output to the switch 8 and the compression circuit 9.

The main memory 5 stores the image data S0 in the second and third fields as shown in FIG.
Is written. Then, in the fourth and subsequent fields, the image data written in the second and third fields are read out, and at the same time, the simple binarization circuit 6 and the pseudo halftone circuit 7 perform binary conversion based on the determination result of the image type. Then, the compression circuit 9 performs compression processing according to the output medium.

The count reset circuit 160 uses the SSG1
Based on the synchronization signals (HD, VD, FLD) output from 1, the signal S7 indicating the determination area and the signal CLEAR for resetting the counter are generated.

In FIG. 4, the outer frame shows an effective screen imaged by the image sensor CCD2. The change amount detection area with respect to the effective screen is a square small area shaded in FIG. The change amount detection area is scanned while moving the effective screen area from left to right and from top to bottom one pixel at a time, in accordance with the output of the image data S0, as indicated by Z in FIG. In this example, 3 ×
The change amount detection area of No. 3 is set so as not to extend from the valid screen. Therefore, the locus of each representative value in the 3 × 3 change amount detection region is formed in a region smaller by 1 pixel on the left and 1 line and 1 line on the upper and lower sides with respect to the effective screen, so that the determination region is as shown in FIG. Set as shown in.

In the image processing apparatus according to the present embodiment, VBLK is a signal representing a vertical effective pixel, and HBLK is a signal representing a horizontal effective screen FLD, VD, H.
It is generated using the D signal. On the other hand, in order to define the determination area, in the present embodiment, the signal VAE indicating the area inside by at least one line in the vertical direction is generated with respect to the signal VBLK indicating the effective screen in the vertical direction, and the signal VAE in the horizontal direction is generated. With respect to the signal HBLK indicating the effective screen, a signal HAE indicating an area inside by at least one pixel in the left-right direction is generated. Further, the signal S7 indicating the determination region is generated by taking the logical product of the signal VAE and the signal HAE.

FIG. 13 shows a state in which a white plate is photographed within the effective screen. The white plate, which is the main subject, is located in the center of the effective screen, but the white plate is present in the peripheral part of the effective screen. Images other than are included. Therefore, the image type determination accuracy can be improved by setting the image type determination region in accordance with the position on the white plate which is the main subject. Therefore, it is possible to variably set the determination region according to the position of the main subject by using the brightness information and the contrast information for each AE / AF detection region extracted by the AE / AF block 13.

Next, the operation of the exposure / focus control section 13 will be described with reference to FIGS.

FIG. 13 shows a state in which a white plate is taken in the screen, and the outer frame shows the entire area being photographed, while the area is divided into minute areas partitioned by a grid. Brightness information is taken in the area.

In general, the main subject is often located in the center of the screen, and thus the white plate, which is the main subject with respect to the effective screen, is located in the approximate center.

On the other hand, looking at the luminance distribution cut at the portion including the white plate in the horizontal direction, it is as shown in FIG. 14 (a). Therefore, in such a case, by setting the determination area in a portion excluding the 1st row and 1st column of the outer frame obtained by dividing the effective pixel into a plurality of pieces, accurate luminance information of the area including the main subject can be obtained, Accurate exposure and focus control will be performed accordingly.

Next, an embodiment corresponding to claims 4 to 7 will be described.

FIG. 15 is a block circuit showing the main part of the image processing apparatus of the second embodiment of the present invention.
FIG. 6 is an explanatory diagram showing areas of the photographing screen in the second embodiment.

The image processing apparatus of the second embodiment has almost the same structure and operation as those of the first embodiment, but is characterized in that a plurality of judgment areas are provided. Therefore, here, only the differences will be referred to, and the description of the same parts will be omitted.

It is generally known that when a photographer takes a picture, he or she naturally pays attention to the vicinity of the central portion when looking through the viewfinder. That is, the subject that the photographer wants to take is
You can think of it as being near the center of the screen.

The present embodiment has been made paying attention to this point, and it is dealt with by providing a plurality of judgment areas as shown in FIG. Although three determination areas are provided in this embodiment, any number may be provided. Further, in the present embodiment, the shape of the determination region is set to be a substantially rectangular shape, but the shape is not limited to this and may be any shape.

As described above, in this embodiment, as shown in FIG. 16, judgment area 1 (hatched portion in the drawing), judgment area 2 (hatched portion in the drawing), judgment area 3 (black portion in the drawing). Three judgment areas (line portion) are provided. In this embodiment, the edge determination amount is weighted closer to the center. That is, weighting is performed so that determination area 1 ≦ determination area 2 ≦ determination area 3 is satisfied.

Note that this weighting is not limited to an integer, and may be a decimal. However, here, for simplicity of explanation, only the case where the weighting coefficient is an integral multiple will be described.

Next, the structure of the main part of the second embodiment will be described.

FIG. 15 is a block diagram showing the main structure of the image processing apparatus of the second embodiment. The other structure is similar to that of the first embodiment, and therefore the description thereof is omitted here.

As shown in the figure, the image processing apparatus of the second embodiment includes a counter reset circuit 160 'corresponding to the counter reset circuit 160 of the first embodiment and a part of the counter circuits 121b, 122b, 123b. Counter circuit 121D corresponding to

The counter reset circuit 160 'has an H level.
A counter 161, a V counter 162, and a judgment area decoder 163 are connected and configured as shown. The H counter 161 and the V counter 162 are respectively shown in FIG.
6 is a counter indicating addresses in the H direction and the V direction, and the determination area decoder 163 indicates which area is currently based on the values of the two counters of the H counter 161 and the V counter 162. Is a circuit for determining. That is, the judgment area decoder 163 decodes each of the judgment areas 1, 2 and 3 and outputs the result through three output signal lines.

The counter circuit 121D is constructed by connecting an adder 164 and a weight setting section 165 as shown in the figure. The adder 164 counts the pixels determined to be edges, and the output of the adder is usually sufficient, but in the present embodiment, it is provided via the weight amount setting unit 165 for weighting. There is. Specifically, the weight amount is set for each of the determination areas,
For example, the determination area 3 has three edge amounts, the determination area 2 has two edges, and the determination area 1 has one edge value. . The edge amount corresponding to the determination area may be set arbitrarily.

Since these output results are calculated for each field, the output data of the adder 164 is reset by a signal synchronized with V blanking so that the same processing is performed again in the next field. There is.

According to the second embodiment, when the image determination is performed, the image detected near the central portion of the screen and the image detected in the peripheral portion are distinguished by weighting, so that the determination rate can be improved. You can

Next, a third embodiment of the present invention will be described.

FIG. 17 is a block circuit diagram showing the main part of the image processing apparatus of the third embodiment.

The image processing apparatus of the third embodiment is almost the same in configuration and operation as the second embodiment, and is characterized in that a plurality of judgment areas are provided as in the second embodiment. , The configuration of the counter circuit is different. Therefore, here, only the differences will be referred to, and the description of the same parts will be omitted. Also, in this third embodiment, the judgment area is the same as that of the second embodiment (see FIG. 16). In this third embodiment, the second embodiment is provided after the counter reset circuit 160 '. A counter circuit 121E different from that is connected. This counter circuit 1
21E is different from the second embodiment in that the weighting means is distinguished by the difference in clock frequency.

Specifically, the counter circuit 121E is
The clock selection means 166, the clock multiplier 167, and the edge counter 168 are connected as shown in the figure. The clock of the determination area 1 (see FIG. 16; the same applies hereinafter) is set to clock 1, the clock of the determination area 2 to clock 2, and the clock of the determination area 3 to clock 3.

Next, the operation of the counter 121E in the third embodiment will be described with reference to FIG.

FIG. 18 is a timing chart showing the operation of the counter 121E in the third embodiment.

In the present embodiment, what is detected as an edge is a period when the edge detection signal is at "H" level,
In the judgment area 1, one pulse of the edge detection signal is counted as one edge. Then, in the judgment area 2 and the judgment area 3, that is, in the portion where the weighting is large, the weighting is changed depending on the difference in frequency such as one, two, or one, two, three by multiplying arbitrarily. I am trying.

In the third embodiment, the same effect as that of the second embodiment can be easily obtained with a simple circuit configuration.

Next, an embodiment corresponding to claims 16 to 23 will be described.

FIG. 19 is a block circuit diagram showing the main parts of an image processing apparatus according to the fourth embodiment of the present invention.

The image processing apparatus of the fourth embodiment has almost the same structure and operation as those of the first embodiment, but the differential change amount is detected from the input image, that is, the N-bit image, and the maximum amount The feature is that the differential change amount of is detected. Therefore, here, only the differences will be referred to, and the description of the same parts will be omitted.

As shown in the figure, the fourth embodiment is provided with a differential change amount detecting section 13a for detecting the differential change amount from the input image, that is, the N-bit image, and the maximum differential change amount in the input image is obtained. It is designed to detect The output signal from the differential change amount detection unit 13a is the image determination circuit 1
5 is input to set the maximum level of the lower limit value of noise. This makes it possible to prevent erroneous determination by removing noise.

FIG. 20 is a timing chart showing the operation of the differential change amount detecting section 13a in the fourth embodiment.

In this timing chart, VD is a blanking signal in the V direction, and AGC is a period for determining the gain by performing AGC control, and is a period of "H" level in the time chart. The shutter is a period in which the shutter is closed during the "L" level period and closed during the "H" level period. In this embodiment, the maximum value is detected during the period when the shutter is at "H" level.

In this embodiment, first, the gain is adjusted in the AGC. After that, the shutter 1a is closed to be in a light-shielding state to create an optical black state. At this time, a detection period for N frames is provided, and at that time, the differential change amount detection unit 13a extracts the maximum value.

FIG. 21 is a block circuit diagram showing the configuration of the differential change amount detection section 13a in the image processing apparatus of this embodiment.

The configuration of the differential change amount detecting section 13a will be described below along the flow of signals.

In the differential change amount detecting section 13a, the input image is input to the edge calculating section 171, and the edge calculating section 17
At 1, the edge is calculated and output. The output edge is input to the register 172 and the comparator 173. Then, in the register 172 and the comparator 173, if the current edge is larger than the previous edge, the edge is stored in the register, and if it is smaller, the operation is performed as it is for N frames, whereby the register 17
At 2, the largest edge in N frames can be picked. By setting this as the lower limit value level in the image determination circuit 15, erroneous determination can be prevented.

In the fourth embodiment, it is possible to prevent erroneous determination of image determination as described above.

Next, a fifth embodiment of the present invention will be described.

FIG. 22 is a block diagram showing the arrangement of the image processing apparatus of the fifth embodiment.

The image processing apparatus of the fifth embodiment has almost the same configuration and operation as those of the first embodiment, and the image pickup device has a charge modulation device (charge modulation device, hereinafter CM).
(Abbreviated as D) is adopted. Therefore, here, only the differences will be referred to, and the description of the same parts will be omitted.

It is generally known that when an amplification type solid-state image pickup device such as CMD is used as an image pickup device, FPN, that is, fixed pattern noise is generated. In such an image pickup device, there occurs a problem that fixed pattern noise is erroneously determined as an edge when an image is determined.

In the fifth embodiment, in view of such a situation, when the image pickup device such as the CMD is used, it is dealt with by adding an FPN frame memory 251 as shown in FIG.

As in the fifth embodiment, the CCD 2 is C
When replaced with a solid-state imaging device such as MD2 ',
Data equivalently in the light-shielded state is transferred to the frame memory 2
Random noise and fixed pattern noise components are also stored by storing in 51. The timing of this capture is
It may be considered that the timing is the same as the timing shown in FIG. When such an image pickup device is used, if the image determination is performed as it is, noise is also determined to be an edge. Therefore, in the present embodiment, the subtracter 252 is used to perform the image determination after suppressing the FPN.

Next, a sixth embodiment of the present invention will be described.

FIG. 23 is a block diagram showing the structure of the image processing apparatus of the sixth embodiment.

The image processing apparatus of the sixth embodiment has almost the same structure and operation as those of the first and fifth embodiments, and adopts the CMD as the image pickup element like the fifth embodiment. It is characterized by Therefore, here, only the differences will be referred to, and the description of the same parts will be omitted.

The sixth embodiment differs from the fifth embodiment in that an FPN edge memory 261 for storing the FPN edges in the memory is provided. The FPN edge memory 261 is the FPN frame memory 25.
The timing generator 10 plays the same role as 1.
Is controlled by the

When such an FPN edge memory is used for image determination, the lower limit value can be variably controlled. In the fifth embodiment, this data is used for the entire image, but in the sixth embodiment, by using the memory 261, the FP address is set for each XY address.
Since N edges are stored, the lower limit level can be changed for each pixel, and there is an effect that more accurate determination can be performed.

The determination area setting means described in claim 1 corresponds to the counter reset circuit 160.

Further, the change amount detecting means according to claim 1 is
It corresponds to the change amount detection circuit 110.

Further, the first arithmetic means according to claim 1 is
The change amount detection circuit 110 and the determination circuits 121a and 122
a, counter circuits 121b and 122b, register 121
c, 122c, corresponding to the CPU 14.

The edge portion detecting means according to claim 1 corresponds to the judging circuit 121a.

Further, the second arithmetic means according to claim 1 is
It corresponds to the average value circuit 130, the comparison circuit 123a, the counter circuit 123b, the register 123c, and the CPU 14.

The image type determining means described in claim 1 corresponds to the CPU 14.

[0175]

As described above, according to the first aspect of the present invention, it is possible to provide the image processing apparatus for accurately determining the image type.

According to the second or third aspect of the invention, in addition to the effect of the first aspect of the invention, a compression process suitable for each image type can be performed.

According to the inventions described in claims 4 to 7, it is possible to provide an image processing apparatus in which the influence of each subject is reduced and the type of image is always accurately determined.

According to the eighth aspect of the present invention, it is possible to provide an image processing apparatus which eliminates the influence of illumination unevenness and accurately determines the type of image.

According to the invention described in claim 9, it is possible to provide an image processing apparatus with a simple structure, which eliminates the influence of illumination unevenness, accurately determines the type of an image, and simplifies the structure.

According to the tenth aspect of the present invention, it is possible to provide an image processing apparatus having a simple configuration and capable of accurately acquiring the characteristic amount for accurately determining the image type.

According to the eleventh aspect of the present invention, it is possible to provide an image processing apparatus capable of eliminating the influence of noise and acquiring the characteristic amount for accurately determining the image type.

According to the twelfth aspect of the present invention, it is possible to provide an image processing apparatus having a simpler configuration and capable of accurately acquiring the characteristic amount for determining the image type.

According to the thirteenth aspect of the present invention, it is possible to provide an image processing apparatus having a simple structure and capable of quickly acquiring a feature amount for accurately determining the image type.

According to the fourteenth aspect of the present invention, it is possible to provide an image processing apparatus that accurately determines the type of image based on an appropriate exposure state.

According to the fifteenth aspect of the present invention, it is possible to provide an image processing apparatus which determines the type of an image more accurately by eliminating the influence of noise under the proper exposure state.

According to the sixteenth to twenty-third aspects of the present invention, it is possible to provide an image processing apparatus which eliminates the influence of noise and more accurately determines the type of image.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an image processing apparatus that is a first embodiment of the present invention.

FIG. 2 is a timing chart showing timing of image determination and signal processing operation based on the image determination in the image processing apparatus of the first embodiment.

FIG. 3 is a block diagram showing a configuration of an image determination circuit and peripheral portions of SSG and CPU in the image processing apparatus of the first embodiment.

FIG. 4 is an explanatory diagram illustrating an operation of a counter reset circuit in the image processing apparatus according to the first embodiment.

FIG. 5 is a block circuit diagram showing a configuration of a change amount detection circuit in the image processing apparatus of the first embodiment.

FIG. 6 is an A / D in the image processing apparatus according to the first embodiment.
It is explanatory drawing explaining the image data signal S0 output from a converter.

FIG. 7 is an explanatory diagram showing an example of division setting of image data in the image processing apparatus of the first embodiment.

FIG. 8 is a block circuit diagram showing a configuration of a determination circuit in the image processing apparatus of the first embodiment.

FIG. 9 is a block circuit diagram showing a configuration of a counter circuit in the image processing apparatus of the first embodiment.

FIG. 10 is an electric circuit diagram showing a configuration of an average value circuit in the image processing apparatus of the first embodiment.

FIG. 11 is an explanatory diagram showing an example of a determination method of an image type determination circuit in the image processing apparatus of the first embodiment.

FIG. 12 is an explanatory diagram showing an example of a determination method of an image type determination circuit in the image processing apparatus of the first embodiment.

FIG. 13 is an explanatory diagram showing the operation of the exposure / focus control unit in the image processing apparatus of the first embodiment, showing a state where a white plate is taken within the screen.

FIG. 14 is a diagram showing a luminance distribution in the exposure / focus control unit in the image processing apparatus of the first embodiment, and FIG. 14B is a diagram showing a relationship between average luminance and frequency. FIG.

FIG. 15 is a block circuit showing a main part of the image processing apparatus of the second embodiment of the present invention.

FIG. 16 is an explanatory diagram showing areas of a shooting screen in the image processing apparatus of the second embodiment.

FIG. 17 is a block circuit diagram showing a main part of an image processing apparatus according to a third embodiment of the present invention.

FIG. 18 is a timing chart showing the operation of the counter in the image processing apparatus of the third embodiment.

FIG. 19 is a block circuit diagram showing a main part of an image processing apparatus according to a fourth embodiment of the present invention.

FIG. 20 is a timing chart showing the operation of the differential change amount detection unit in the image processing apparatus of the fourth embodiment.

FIG. 21 is a block circuit diagram showing a configuration of a differential change amount detection unit in the image processing device of the fourth embodiment.

FIG. 22 is a block diagram showing the configuration of an image processing apparatus according to a fifth embodiment of the present invention.

FIG. 23 is a block diagram showing the configuration of an image processing apparatus according to a sixth embodiment of the present invention.

FIG. 24 is a diagram showing a luminance distribution in one image.

FIG. 25 is a diagram illustrating operations of a comparison circuit and a determination circuit in the image processing apparatus according to the first embodiment.

FIG. 26 is a diagram showing an example of frequency of pixel data change amounts in a document image.

FIG. 27 is a diagram showing an example of the frequency of the amount of change in pixel data in a natural image.

[Explanation of symbols]

 1 ... Shooting optical system 2 ... CCD 3 ... Process circuit 4 ... A / D converter 5 ... Main memory 6 ... Simple binarization circuit 7 ... Pseudo halftone processing circuit 8 ... Switch 9 ... Compression circuit 10 ... Timing generator (TG) 11 ... Sync signal generation circuit (SSG) 12 ... Memory controller 13 ... Exposure / focus control section 14 ... CPU 15 ... Image determination circuit 110 ... Change amount detection circuit 160 ... Counter reset circuit 121a, 121b ... Determination circuit 121b, 122b, 123b ... Counter circuit 123a ... Comparison circuit 121c, 122c, 123c ... Register Agent Attorney Susumu Ito

Claims (23)

[Claims] 1. A determination area setting means for setting a determination area for determining an image type in a predetermined area in the screen, and an object for detecting the amount of change in pixel data set in the screen. A change amount detecting unit that sequentially obtains a change amount of pixel data in the change amount detecting region while moving the change amount detecting region so as to cover the corresponding portion on the determination region, and the change amount detecting unit detects the change amount. First computing means for obtaining a first determination feature amount based on frequency information in the determination area for each variation amount; edge portion detecting means for detecting an edge portion of an image in the variation amount detection area; Second computing means for obtaining a second determination feature amount based on frequency information in the determination region for pixel data of pixel groups forming the edge portion detected by the edge portion detecting means; Calculation Image type determining means for determining at least the type of the image of the set determination area from the first determination characteristic amount by the step and the second determination characteristic amount by the second computing means. An image processing device characterized by: 2. The image type according to claim 1, further comprising: first data compression means suitable for compressing natural image data, and second data compression means suitable for compressing character image data. Adaptively selecting the first or second data compression means according to the output of the determination means,
The image processing apparatus according to claim 1, further comprising means for performing data compression processing of at least the set determination area. 3. The image processing apparatus according to claim 2, wherein the first data compressing means and / or the second data compressing means performs image binarization processing. 4. The change amount detection means is configured to set a change amount detection area so as to be included in the screen regardless of the size of the determination area. The image processing apparatus according to item 1. 5. The image processing apparatus according to claim 1, wherein the determination area setting means variably sets the determination area. 6. The image processing apparatus according to claim 1, wherein the determination area setting means is capable of setting a plurality of determination areas. 7. The method further comprises means for weighting frequency information for calculating the first and second determination feature amounts corresponding to the plurality of determination regions set. The image processing apparatus according to claim 6. 8. The change amount detection means comprises means for normalizing the change amount of the change amount detection area with average pixel data in the change amount detection area. The image processing apparatus according to item 1. 9. The change amount detection means sets the change amount detection area as a rectangular area of m × n (m and n are arbitrary natural numbers) pixels, and pixel data of at least a corner portion of the change amount detection area. The image processing apparatus according to claim 1, wherein the image processing apparatus is configured to detect the amount of change in pixel data by using. 10. The first calculation means changes the variation amount of the pixel data obtained by the variation amount detecting means.
One condition is determined, the number of change amount detection regions to which pixel data satisfying each condition belongs is counted, and the ratio of each count value is used as the first determination feature amount. The image processing apparatus according to claim 1, wherein: 11. The first calculation means excludes from the count value the number of change amount detection regions to which the pixel data change amount calculated by the change amount detection means is less than a predetermined value. The image processing apparatus according to claim 10, wherein the image processing apparatus is configured as described above. 12. The edge part detecting means is adapted to detect the edge part under either one of two different conditions for judging the amount of change in pixel data obtained by the amount of change detecting means. The image processing apparatus according to claim 10, wherein 13. The second calculation means includes the number of change amount detection areas in which the average pixel data in the change amount detection area is larger or smaller than a predetermined value, and the number of change amount detection areas including an edge portion. 2. The image processing apparatus according to claim 1, wherein the ratio of the second determination feature amount is set as the second determination feature amount. 14. A means for generating image data of at least the set determination area, and means for performing a focusing operation or an exposure control operation prior to determining an image type. The image processing device according to claim 1. 15. A means for generating image data of at least the set determination area, and means for varying conditions for obtaining the first and second determination feature amounts according to an exposure condition. The image processing apparatus according to claim 1, wherein: 16. A means for generating image data of at least the set determination area, for obtaining data of a pixel in a light-shielded state, and for determining the type of image in consideration of the data. The image processing apparatus according to claim 1, wherein the image processing apparatus comprises: 17. The means for determining the type of the image includes acquiring data of pixels in a light-shielded state,
The differential change amount in the N field period (N is an arbitrary natural number) is detected to obtain the maximum differential change amount level in the N field period, and is used when determining the image type. The image processing device according to claim 16, wherein the image processing device is a device. 18. The means for generating the image data is composed of an amplification type image pickup device, and the image after the fixed pattern noise generated by using the amplification type image pickup device is removed is determined as the image type. The image processing apparatus according to claim 16, further comprising means for providing the image processing apparatus. 19. The means for generating the image data is composed of an amplification type image pickup device, and is provided with means for providing the differential change amount of fixed pattern noise corresponding to each pixel to the determination of the image type. Claim 1 characterized by the above.
7. The image processing device according to 6. 20. An image processing apparatus for determining the type of an image captured by an optical system, comprising: a light blocking state signal component obtaining means for obtaining an image signal component when optically in a light blocking state, the light blocking state An image processing apparatus comprising: a unit that determines a type of an image in consideration of a signal component from a signal component acquisition unit. 21. The light-shielding state signal component acquisition means is n
A differential change amount detection means for the field period is provided, and this n
21. The image processing apparatus according to claim 20, wherein the maximum differential change amount in the field period is acquired and used when determining the image type. 22. The optical system includes an amplification type solid-state imaging device, and means for determining the type of the image after the fixed pattern noise generated by using the amplification type solid-state imaging device is removed. The image processing apparatus according to claim 20, further comprising: 23. The optical system includes an amplification type solid-state imaging device, and is configured to use a fixed pattern noise edge corresponding to each pixel from the fixed pattern noise when determining a type of an image. The image processing apparatus according to claim 20, wherein