JP2002077768A - Video signal processing device - Google Patents

Abstract

(57) [Problem] To switch to an optimum screen display size on a wide-screen television by detecting an aspect ratio in a horizontal direction of a video having a non-image portion added to both sides. An aspect ratio detecting means having a vertical and horizontal detecting function, a microcomputer for calculating an enlargement magnification according to an output from the aspect ratio detection means, and an enlargement means for performing an enlargement process according to the enlargement magnification Is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen display size switching device using an aspect ratio detection circuit used in a television signal processing device.

[0002]

2. Description of the Related Art In an NTSC system, the aspect ratio of a video signal is
4: 3, and receivers for displaying this have been widely used. However, in recent years, in the MUSE system, which is one of high-definition television systems, the aspect ratio of video signals is 1
Television receivers are standardized at 6: 9, and accordingly, television receivers capable of displaying a landscape screen called wide television have become widespread.

[0003] On the other hand, the images displayed on these
It came in a variety of formats. For example, a movie is originally a landscape screen, but to fit a 4: 3 screen,
Black areas with no image above and below the screen (hereinafter referred to as non-image areas)
Are often broadcasted in a display form called a so-called letter box format, and more and more as packaged software.

[0004] Even in the case of the letterbox format, there are actually images in display forms with various aspect ratios. For example, as a typical example, an aspect ratio of 1.85: 1 as shown in FIG. There is a Vista size, 2.35: 1 cinema scope, etc. These also differ depending on whether the movie software is domestic or foreign, for example, and the display form such as the presence or absence of subtitles and the number of lines is quite various.

[0005] In the future, it is expected that video software having such a landscape screen will increase, and video signals having different aspect ratios such as 4: 3, 16: 9 and movie software on a screen having a wide aspect ratio are to be displayed. The problem is how to display them easily.

[0006] For example, when a wide-screen television receiver receives a letter-box format image as shown in FIG. 10A as it is, as shown in FIG. The image is displayed as if it were crushed. Therefore, the wide TV receiver performs vertical enlargement processing of the image, enlarges the video signal in the vertical direction so that the non-image part at the top and bottom of the screen is not displayed on the screen, and corrects the crushed image part to the correct image. (FIG. 10C). By performing such processing, an image can be reproduced on the entire display screen, so that a powerful image can be enjoyed.

In order to perform the above-mentioned enlargement operation, it is necessary to know the boundary position between the video part and the non-picture part of the input letterbox video. Conventionally, video signal processing apparatuses for this purpose have been proposed.

As a conventional example of the above-mentioned apparatus, for example,
No. -32889. FIG. 3 is a block diagram of this conventional publication, in which a Y / C separation circuit 202 that separates an input video signal into a luminance signal and a chroma signal, and compares the separated luminance signal with a predetermined threshold. When there is a signal exceeding the threshold, a luminance level comparison circuit 203 that outputs a signal of logic level H, a synchronization separation circuit 204 that separates a horizontal synchronization signal and a vertical synchronization signal from the separated luminance signal, Video area determination circuit 20 that performs the determined video determination
5, 206, a gate generation circuit 207 that creates various gate pulses based on horizontal and vertical synchronization signals, a video area determination circuit 208 that compares video data sent individually and determines a video area, An arithmetic circuit 209 for calculating data such as a video range from video start data and video end data,
Screen size switching circuit 210 for switching to the optimal screen size
And an image position control circuit 211 for controlling the display position of the image displayed on the display screen from the output of the arithmetic circuit 209.

[0009]

In the conventional NTSC system for television broadcasting, the aspect ratio is 4: 3, and the television for displaying the aspect ratio is also 4: 3. With the advent of the 16: 9 aspect ratio widescreen TV, a video with a non-image area added at the top and bottom, such as a letterbox format in which a 16: 9 video is embedded in a 4: 3 video area, appears, filling the entire screen. For display, vertical aspect ratio detecting means for detecting upper and lower non-image portions is required.

However, in recent years, domestic video signals are NT
In addition to SC broadcasts, digital broadcasts, PC output, and other formats have become diversified. In addition, BS digital broadcasting is scheduled to start in December this year, and the diversification of formats used, such as digital high-definition television and data broadcasting, is expected.

As an example, FIG. 4 shows a 1080i format video source scheduled for BS digital broadcasting and its display format on a wide-screen television.

Is an image sent with an aspect ratio of 16: 9. Is an image obtained by up-converting the current NTSC to 1080i. When this is displayed on a wide-screen television, the image becomes a picture in which non-image portions are added to both sides as shown in the figure. In this case, non-image portions on both sides are detected, and customer needs for screen display as shown at the far right of FIG. In order to realize this, detection in the horizontal direction is required.

In the conventional example described above, the image range in the vertical direction is detected, and the enlargement control is performed. No consideration is given to the horizontal direction.

An object of the present invention is to provide a video signal processing apparatus having an aspect ratio detection circuit capable of detecting a horizontal direction, in order to solve the above technical problem.

[0015]

In order to achieve the above object, an image signal processing apparatus according to the present invention comprises an aspect ratio detecting means having a vertical and horizontal detecting function, and an output from the aspect ratio detecting means. And a magnifying unit that calculates an enlargement magnification according to the magnification and an enlargement unit that performs an enlargement process according to the enlargement magnification.

[0016]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention. In FIG. 1, 101 is an input terminal, 102 is a low-pass filter, 103 is a binarization unit (brightness level comparison unit), 104 is a pixel counter, 105 is a line determination unit, 106 is a distribution slice level, 107 is a boundary determination unit, 108 is a horizontal / vertical synchronization signal input terminal, 109 is a luminance slice level, 110 is a gate pulse generating means, 111 is various parameters, 112 is an aspect ratio detecting means, 113 is a vertical direction detecting function, 114 is a horizontal direction detecting function, 115 Is the microcomputer,
16 is an enlargement magnification, 117 is an enlargement means, and 118 is a picture tube.

In describing the circuit operation of FIG. 1, the operation of the vertical direction detecting function 113 in the aspect ratio detecting means 112 will be described first. A luminance signal obtained by Y / C separation of a video signal is input from an input terminal 101. The input luminance signal is filtered by a low-pass filter 102 to remove high-frequency components including noise and the like. If the luminance signal is higher than the luminance slice level 109, the binarizing means (luminance level comparing means) 103 determines that there is a video, and outputs a determination signal of, for example, a logical level H.
If it is smaller than 9, it is determined that there is no video and the logical level is L
Is output. The gate pulse generating means 110 creates a detection gate pulse based on the sent horizontal and vertical synchronization signals 108 and the set value of the start / end position from the microcomputer 113, and sends it to the pixel counter 104. Pixel counter 104
Counts, for each line, how many discrimination signals of the logic level H exist in the detection gate pulse period, and outputs the count number. If the pixel count number in one line is larger than the distribution amount slice level 106, the line determination means 105 determines that the line has video, and outputs a determination signal of a logical level H, for example. Conversely 1
The pixel count number in the line is the distribution amount slice level 106
If the number is less than that, the line is determined to have no image, and a determination signal of a logical level L is output. The boundary determination means 107 detects a vertical boundary between the video portion and the non-image portion based on the line determination result, and outputs video start position and video end position information to the microcomputer 115 for each field. The microcomputer 115 calculates an image width (image end position−image start position + 1) from the result from the aspect ratio detection unit, and outputs a vertical enlargement factor 116 to the enlargement unit 117 according to the image width. The enlargement means 117 performs an enlargement process according to the enlargement magnification 116.

As described above, the vertical enlargement is controlled according to the detection in the vertical direction. Next, detection in the horizontal direction will be described.

When an image obtained by up-converting the current NTSC to 1080i as shown in FIG. 8 in the BS digital broadcasting standard is input to the circuit of FIG. 1, for example, a screen display as shown on the right side of FIG. It is necessary to perform horizontal enlargement by judging whether or not the image has a non-image portion on both sides. It is known that the horizontal video start / end position in FIG. 8 is constant regardless of the video source, and the horizontal magnification is also constant regardless of the video source. The number of samples in the non-image part on both sides and the image part in the center are determined to be 240 and 1440. Therefore, in the same figure, it is sufficient to detect that X: no image portion, Y: video portion, and Z: no image portion. By switching the detection range in the gate pulse generation means 110, the horizontal direction detection function 114
Then, the microcomputer 115 detects that both sides are non-image portions, and detects that the center portion is an image portion. Hereinafter, detection in the horizontal direction will be described according to an example of a control method of the microcomputer 115.

FIG. 5 shows an example of a control algorithm of the microcomputer 115. First, in the determination as to whether or not both sides are non-image portions, for example, FIG.
The detection range in the horizontal direction is set as shown in FIG. The vertical direction is set to include, for example, all the effective scanning lines as shown in the figure (step F2). In other words, in the hatched portion in FIG. 9, the process of detecting the vertical direction is performed, and the detection results of the video start position and the video end position are output to the microcomputer 115. Microcomputer 1
At 15, for example, if the video start and end positions have the same value, it is determined that the image is a non-image portion (step F3). next,
Within the 1440 sample range, for example, a horizontal gate pulse is set as shown in FIG. 9B. The vertical direction may be the same as described above (step F4). In this detection range, the result of the vertical direction detection (video start / end position) is
Output to If the microcomputer 115 detects that the video start position and the end position are different values and that the video width (video end position−video start position + 1) is equal to or greater than a predetermined value, the microcomputer 115 determines that the image is a video part (steps F5 and F6). , F7). The predetermined value can be set arbitrarily. From the above two determination results, it can be detected that an image as shown in FIG. 8 in which both sides of the screen are non-image portions and the center is an image portion is input. As described above, since the horizontal video start / end positions in FIG. 8 are constant regardless of the video source, the microcomputer 115 determines at the time that it is determined that the video in FIG. 116 is output to the enlarging means 117, and the enlarging means is output.
At 117, the screen display size in the horizontal direction is switched.

As described above, according to the present embodiment, FIG.
When an image as shown in (a) is input, a non-image part on both sides and an image part in the center are detected, and the screen display shown in FIG.

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

FIG. 6 is a block diagram showing the configuration of the second embodiment of the present invention. In FIG. 6, the first type shown in FIG.
The same components as those of the embodiment are denoted by the same reference numerals, and description thereof will be omitted. This embodiment differs from the first embodiment in FIG. 1 in that the non-image part and the central image part on both sides in FIG. 8 are determined based on the brightness of the screen.

The operation of the third embodiment different from the first embodiment will be described below.

A black line counter 11 for counting the lines determined to have no image in the line determination means 105
9 is provided. The aspect ratio detection means 112 outputs the number of counts by the black line counter 119 (hereinafter, referred to as the number of black lines) to the microcomputer 115, and the number of black lines is equal to or more than a predetermined number of lines on the microcomputer side, or the total number of lines. If so, it is determined that both sides are non-image portions (dark). Similarly, if the number of black lines is equal to or less than the predetermined number of lines in the central portion of the screen, it is determined that the image portion is (bright). The predetermined number of lines can be set arbitrarily.
As described above, from the determination result that both sides are dark and the central part is bright, it can be known that an image as shown in FIG. 8A has been input. In addition, the video start /
When used in combination with the end position result, data reliability can be improved.

As shown in FIG. 7, in order to improve the accuracy of light / dark detection, the distribution amount slice level 120 can be set for detecting the number of black lines, and a new line determination means may be provided.

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

FIG. 11 is a block diagram showing the configuration of the third embodiment of the present invention. 11, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. FIG. 1 shows this embodiment.
The difference from the first embodiment is that the horizontal direction detecting function is used together with the vertical detecting means.

The operation of the third embodiment different from that of the first embodiment will be described below.

As described in the first embodiment, the horizontal direction detection can be determined by the video start / end position by the vertical direction detection. Therefore, by using the microcomputer 115 to control the switching of the detection range in the gate pulse generating means 110 using only one of the means,
It is possible to perform both vertical detections.

FIG. 12 shows an example of a control algorithm of the microcomputer 115. Hereinafter, both horizontal and vertical detection will be described with reference to FIG. First, the detection in the horizontal direction described in the first embodiment is performed. If it is not determined that the image is a non-image portion in determining whether or not the image has a non-image portion on both sides,
Assuming that horizontal enlargement processing is not necessary, detection in the vertical direction is started (steps F3 and F11). In the next field, the detection range in the gate pulse generation unit 110 is switched to the setting for vertical direction detection, a vertical magnification according to the result of the aspect ratio detection unit 112 is calculated, and output to the enlargement unit (step F12, F13, F14). The uncertainty determination (step F10) in FIG. 12 is a case where it does not apply to any of the situations to be predicted, and performs processing for retaining the previous screen display size.

According to the present embodiment, detection in the horizontal direction is possible only with the vertical direction detection function, and the circuit scale can be reduced.

[0033]

According to the present invention, it is possible to detect the horizontal direction by using the conventional aspect ratio detecting means having only the vertical direction detecting function. As an example, the current NTSC, which is already the BS digital broadcasting standard, is used. Even for images upconverted to 1080i and with non-image areas added on both sides, the screen display can be switched to full-screen widescreen display to provide powerful images.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram for explaining an example of a letterbox video.

FIG. 3 is a block diagram of a conventional technique.

FIG. 4 is a diagram showing video sources and display formats in BS digital broadcasting.

FIG. 5 is a flowchart for explaining the operation of the microcomputer according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a second embodiment of the present invention.

FIG. 7 is a diagram showing another configuration example of the second embodiment of the present invention.

FIG. 8 is a conceptual diagram of horizontal direction detection in the present invention.

FIG. 9 is a diagram illustrating a detection method of horizontal direction detection according to the present invention.

FIG. 10 is a diagram showing screen display switching when a letterbox image is input.

FIG. 11 is a block diagram showing a third embodiment of the present invention.

FIG. 12 is a flowchart illustrating an operation of the microcomputer according to the third embodiment of the present invention.

[Explanation of symbols]

100: color signal input terminal, 101: luminance signal input terminal, 102:
Low-pass filter, 103: image binarization means, 104: pixel counter, 105: line determination means, 106: distribution amount slice level, 107: boundary determination means, 108: horizontal / vertical synchronization signal,
109: luminance slice level, 110: gate pulse generation means, 111: various parameters, 112: aspect ratio detection means, 113: vertical direction detection function, 114: horizontal direction detection function,
115 ... microcomputer, 116 ... enlargement magnification, 117 ... enlargement means, 118 ...
CRT, 119: black line counter, 120: black line detection distribution slice level, 201: video input terminal, 202: Y / C
Separation circuit, 203: luminance level comparison circuit, 204: synchronization separation circuit, 205: video area determination circuit, 206: video area determination circuit, 207: gate generation circuit, 208: video area determination circuit,
209: arithmetic circuit, 210: screen size switching circuit, 211: video position control circuit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasutaka Tsuru 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Digital Media Development Division, Hitachi, Ltd. (72) Inventor Yoshiaki Mizuhashi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Address Digital Media Development Division, Hitachi, Ltd. (72) Inventor Takashi Hasegawa 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Digital Media System Division, Hitachi, Ltd. (72) Kazuo Ishikura, Kodaira, Tokyo 5-20-1, Kamizuhoncho In the System LSI Development Center of Hitachi, Ltd. (72) Inventor Masato Sugiyama 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term, Digital Media Development Division, Hitachi, Ltd. Reference) 5C023 AA02 AA38 BA02 CA01 5C025 BA02 BA11 BA 30 DA10

Claims (4)

[Claims] 1. A video signal processing apparatus for switching a video signal having a different aspect ratio to an optimum screen display size, wherein a vertical direction detection for detecting a vertical video start position and a vertical video end position of an input video signal. Aspect ratio detection means having a function and a horizontal direction detection function for detecting whether or not the image has a non-image portion on both sides of the screen, and calculates a magnification of the image from output data from the aspect ratio detection A video signal processing apparatus, comprising: a screen display control unit that performs an enlargement process that performs an enlargement process according to the enlargement magnification. 2. A horizontal direction detection function detects a vertical image start position and an end position on both sides and a center portion of the screen, and based on a result, determines whether or not the image has a non-image portion on both sides of the screen. 2. The video signal processing apparatus according to claim 1, wherein the image display control unit performs horizontal enlargement control. 3. The horizontal direction detection function detects the number of lines on both sides and the center of the screen where no image is determined, and determines whether or not the image has a non-image part on both sides of the screen based on the result. 3. The video signal processing apparatus according to claim 1, wherein the determination is made, and the screen display control means calculates a horizontal magnification. 4. The aspect ratio detecting means realizes a horizontal direction detecting function and a vertical direction detecting function by changing a detection gate setting when detecting a vertical image start / end position. Video signal processing device.