JPH08195919A - Picture size controller - Google Patents

Abstract

PURPOSE: To accurately detect upper and lower mask parts and to display that image on a video display part in the optimum state. CONSTITUTION: A low-pass filter 1 removes the high frequency component of a video signal and an A/D converting circuit 2 converts that video signal to digital data. A synchronizing signal separator circuit 3 separates a synchronizing signal from the video signal and a timing generating circuit 4 supplies a timing signal to an arithmetic circuit 5. The arithmetic circuit 5 vertically fetches the data at horizontal positions so that the plural horizontal positions can be provided. The luminance level of upper and lower mask parts is detected from those data and with this luminance level as a reference, data are threshold processed. The binary data are horizontally integrated and based on the integrated data, upper video start and lower video end line positions are calculated. As a result, in the case of a laterally long image, an aspect conversion circuit 6 is operated and that image is displayed on a cathode-ray tube 7.

Description

Detailed Description of the Invention

[0001]

The present invention has an aspect ratio of 16: 9.
The present invention relates to a screen size adjusting device suitable for use in a television receiver having an image display unit (CRT, etc.) and having an aspect conversion circuit, and in particular, the upper and lower parts of a video signal are masked with an aspect ratio of 4: 3. The present invention relates to a screen size adjusting device capable of automatically determining whether a landscape image is a long image and displaying the image in an optimal state on a video display unit without a viewer performing a complicated operation.

[0002]

2. Description of the Related Art Recently, a television receiver (hereinafter referred to as wide TV) equipped with a wide aspect video display portion having an aspect ratio of 16: 9 has been introduced, and also shown in FIG. 24 as a video source. As described above, various sources such as a Vista source having an aspect ratio of 4: 3 but a non-image portion (mask portion) existing in the upper and lower portions, and various modes in which an image existing range (vertical size) is different are supplied. Has become.

A video source as shown in FIG.
When it is displayed on V as it is, it becomes a horizontally elongated image as shown in FIG. 25 (A), but if the viewer manually sets the aspect conversion, as shown in FIG. 25 (B), the vertical center of the image exists. The image in the range of the aspect ratio of 16: 9 is enlarged, and it is possible to display by making full use of the wide aspect image display unit.

As described above, in the conventional wide TV, when displaying a video source such as a movie whose upper and lower parts are masked, the viewer has to manually operate the aspect conversion. Since the widths of the upper and lower mask portions are different or not necessarily constant for each video source, the aspect conversion as described above requires an extremely complicated operation. Therefore, it automatically determines whether the video signal is a horizontally long image with the upper and lower parts masked, and adjusts the screen size so that the image is displayed in the optimal state on the video display unit without the viewer performing complicated operations. A device has been developed, and a wide TV equipped with the device has also appeared.

[0005]

However, in the conventional screen size adjusting apparatus, when the luminance level of the upper and lower mask portions is high or there is not much difference between the luminance level of the upper and lower mask portions and the luminance level of the image. It becomes difficult to detect the boundary (edge) between the mask part and the image, and it takes time to detect the boundary, and the time to adjust the screen size displayed on the image display part becomes long, which makes viewers feel uncomfortable. There was a problem that it might give. Further, even when additional information such as subtitles is inserted in the upper and lower mask portions, it becomes difficult to detect the boundary between the mask portion and the image, or it is accurately determined whether or not the additional information exists. However, there is a problem that additional information may be deleted and aspect conversion may be performed.

The present invention has been made in view of the above problems, and it is a screen size adjusting device capable of accurately detecting upper and lower mask portions, and whether or not additional information exists in the upper and lower mask portions. An object of the present invention is to provide a screen size adjustment device that can be accurately identified.

[0007]

In order to solve the above-mentioned problems of the prior art, the present invention determines the presence or absence and the position of upper and lower mask portions in an incoming video signal, and determines the screen size according to the image. In a screen size adjusting device for adjusting, a low-pass filter for removing a high frequency component of the incoming video signal, an A / D conversion circuit for converting the video signal output from the low-pass filter into digital data, and a data capture timing The upper and lower mask portions are detected by capturing the digital data output from the A / D conversion circuit by a signal for one or a plurality of fields so as to be a plurality of horizontal positions vertically over one field at a predetermined horizontal position. And an aspect conversion of the incoming video signal based on the detection result of the arithmetic circuit. And the aspect ratio conversion circuit is provided,
(1) In the arithmetic circuit, a first means for detecting the brightness levels of the upper and lower mask portions and a predetermined reference value based on the brightness levels of the upper and lower mask portions detected by the first means are used as references. Second means for binarizing the digital data into a first value and a second value;
Means for integrating the digital data binarized by the means in the horizontal direction, and detecting a point where the digital data integrated by the third means exceeds a predetermined level to start the upper image. Provided is a screen size adjusting device comprising: a line position and a fourth means for obtaining a lower image end line position.
(2) In the arithmetic circuit, the first means for detecting the brightness levels of the upper and lower mask portions, and a predetermined reference value based on the brightness levels of the upper and lower mask portions detected by the first means are used as references. Second means for binarizing the digital data into a first value and a second value;
The digital data binarized by the means is divided into a plurality of areas in the horizontal direction of the screen, and the area closer to the upper end of each area is determined as the upper video start line position in that area, and the lower end A third means for determining a position close to the part as a lower video end line position in the area, and an upper video start line position and a lower video end line position in each area obtained by the third means, Fourth means for deciding the one closer to the upper end as the upper image start line position for the whole image, and deciding the one closer to the lower end for the lower image end line position as the whole image, and the third means The upper image start line position and the lower image end line position in each area obtained by the above, and the image obtained by the fourth means. Fifth determining a variation of the upper image start line position and the lower video end line position as the body
And a sixth means for operating the aspect conversion circuit according to the variation obtained by the fifth means, the screen size adjusting device being provided. First arithmetic means in the arithmetic circuit for detecting the luminance levels of the upper and lower mask portions, and the digital data with reference to a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. To a first value and a second value, and second means for binarizing and converting the upper video start line position and the lower video end line based on the digital data binarized by the second means. Third means for obtaining a position, fourth means for ternarizing at least a part of the digital data obtained by the A / D conversion circuit into first to third values, and fourth means hand of And a fifth means for detecting whether or not additional information is superimposed on the upper and lower mask portions based on the data ternarized by the above. (4) A first means for detecting the brightness levels of the upper and lower mask portions in the arithmetic circuit, and a predetermined reference value based on the brightness levels of the upper and lower mask portions detected by the first means. As a second means for binarizing and converting the digital data into a first value and a second value, and a third means for horizontally integrating the digital data binarized and converted by the second means. Means and fourth means for obtaining an upper video start line position and a lower video end line position by detecting a point where the digital data accumulated by the third means exceeds a predetermined level. Fifth means for detecting a point having a level smaller than the predetermined level but not 0 from the vertical end of the integrated digital data to the upper video start line position or the lower video end line position, and By detecting the distance between the upper image start line position or the lower image end line position and the point having a non-zero level obtained by the means of 5, it is determined whether or not additional information is superimposed on the upper and lower mask portions. The present invention provides a screen size adjusting device characterized by comprising a sixth means for detecting.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A screen size adjusting device of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of a screen size adjusting apparatus of the present invention, FIG. 2 is a diagram for explaining a video data capturing method by the screen size adjusting apparatus of the present invention, and FIG. 3 is a screen size adjusting apparatus of the present invention. FIG. 4 is a waveform diagram showing an example of sampling data, FIG. 4 is a waveform diagram for explaining the operation of the screen size adjusting apparatus of the present invention, and FIGS. 5 to 7 are diagrams for explaining the operation of the screen size adjusting apparatus of the present invention. FIG. 8 is a waveform diagram for explaining the operation of the screen size adjusting apparatus of the present invention. FIGS. 9 and 10 are diagrams for explaining the operation of the first embodiment of the screen size adjusting apparatus of the present invention. Is a diagram showing an example of an image in which the boundary between the image and the upper and lower mask portions varies, FIGS. 12 and 13 are diagrams for explaining the operation of the first embodiment of the screen size adjusting apparatus of the present invention, and FIG. 14 is a book. Other than the screen size adjusting device of the invention Block diagram showing the configuration, Fig 15 is showing an example of an image difficult to determine the boundary between the image and the vertical mask portion, FIG. 16 shows the results obtained by sampling the image shown in FIG. 15, FIG. 1
7 is a diagram for explaining the operation of the second embodiment of the screen size adjusting apparatus of the present invention, FIG. 18 is a diagram showing an example of an image in which subtitles are superimposed on the lower mask portion, and FIGS. For explaining the operation of the third embodiment of the screen size adjusting apparatus of FIG. 21, FIG. 21 is a view showing an example of an image in which characters are superimposed on the upper mask portion, and FIGS. 22 and 23 are screen size adjusting of the present invention. It is a figure for demonstrating operation | movement of 4th Example of an apparatus.

First, the structure of the screen size adjusting apparatus of the present invention shown in FIG. 1 and the operation of the first embodiment will be described. In FIG. 1, the incoming video signal is a low-pass filter 1,
It is input to the sync separation circuit 3 and the aspect conversion circuit 6.
The low-pass filter 1 removes the high frequency component of the input video signal and inputs it to the A / D conversion circuit 2. This is because the frequency forming the mask portion in the image is a low-frequency component, so the high-frequency component is unnecessary to detect the mask portion,
This is because it is sufficient to sample the low frequency component of 0 to 800 kHz in the video signal. Also, the low-pass filter 1 mixes many noise components when the S / N of the video signal is bad, so it removes pulse noise due to random noise and sparks, and at the same time prevents false detection. The A / D conversion circuit 2 in the subsequent stage also has a role of being able to use an inexpensive one having a low sampling frequency. Since the required frequency component is low, even if the incoming video signal is a composite signal, NTSC
The color component superimposed at 3.58 MHz cannot pass, but only the luminance component passes. Therefore, the incoming video signal operates in the same manner whether it is a luminance signal after Y / C separation or a composite signal.

On the other hand, the sync separation circuit 3 separates the sync signal from the input video signal, and supplies the timing generation circuit 4 with video timing signals such as a horizontal sync signal and a vertical sync signal. The timing generation circuit 4 supplies the arithmetic circuit 5 with a capture timing signal for capturing video data. Then, the arithmetic circuit 5 takes in the video data converted into the digital signal by the A / D conversion circuit 2 according to the take-in timing signal, analyzes the video data by a method which will be described later in detail, and the incoming video signal goes up and down. It is determined whether the image is a horizontally long image with a portion masked. It should be noted that a microcomputer can be used as the arithmetic circuit 5, and in this case, there is no problem even if the A / D conversion circuit 2 has a built-in microcomputer. Further, here, the timing generation circuit 4 is used to operate the arithmetic circuit 5.
Although the timing signal for fetching video data is supplied to the timing generator circuit 4, the timing generator circuit 4 is not always necessary if the same fetch control can be performed by the horizontal synchronizing signal and the vertical synchronizing signal in the arithmetic circuit 5.

Then, as a result of the arithmetic circuit 5 analyzing the image data, the incoming image signal is masked in the upper and lower parts of FIG.
If it is determined that the image is a horizontally long image having an aspect ratio of 4: 3 as shown in FIG. 4 but an aspect ratio of 16: 9 in the central portion in the vertical direction, the arithmetic circuit 5 causes the aspect conversion circuit 6 to operate as shown in FIG. ), And instruct to perform aspect conversion. The aspect conversion circuit 6 converts the aspect of the input video signal according to this instruction and supplies it to the cathode ray tube 7. The aspect conversion circuit 6 is a well-known aspect conversion means for converting the aspect of the image by digital signal processing, or converting the aspect of the image by manipulating at least one of the horizontal and vertical deflection widths. Therefore, on the tube surface of the cathode ray tube 7, an image whose aspect is converted into an optimum state for the incoming video signal is displayed.

Now, a method of capturing video data by the arithmetic circuit 5 of the present invention and a method of analyzing the same will be described.
As shown in FIG. 2, the arithmetic circuit 5 first captures video data over one field in the vertical direction of the screen at a predetermined horizontal position (1) at the capture timing designated by the timing generation circuit 4. In the next field, the position in the horizontal direction is delayed backward, the image data is similarly captured at the position (2) in the horizontal direction, and thereafter, when the final position (8) in the horizontal direction is similarly captured, the leading position (1) in the horizontal direction is obtained. Return to. In this way, if the operation of capturing the video data is continuously performed until the horizontal sampling of the screen is completed, the data of the entire screen can be obtained. When the entire screen is divided into eight parts in the horizontal direction as in the present embodiment, it is necessary to divide the entire screen into eight by the time sampling of the entire screen is completed.
Requires a field. Of course, this division width may be narrowed or widened, and if the arithmetic circuit 5 has high capability and abundant memory, the entire screen may be sampled at the same time.

If the incoming video signal is a video in which the upper and lower sides are masked as shown in FIG. 24, the vertical digital data fetched as described above will have a waveform as shown in FIG. 3A as an example. . In this case, the upper video start line position and the lower video end line position may be detected. Also, if the video has subtitles superimposed on the lower mask part,
The digital data in the vertical direction has a waveform as shown in FIG. 3B as an example. In this case, it is necessary to detect the subtitle start line position and the subtitle end line position in addition to the upper video start line position and the lower video end line position. Note that in the following description, subtitles are not superimposed in FIG.
The video like this will be described as an example.

Further, in FIG. 4, (A) shows sampling data (vertical data at one horizontal position) when the luminance level of the mask portion is low and the image portion and the mask portion can be relatively clearly distinguished. And
(B) shows the sampling data when the luminance level of the mask portion is high and it is difficult to distinguish the image portion and the mask portion. 4A and 4B, the left side is the upper part of the screen and the right side is the lower part of the screen. In the present invention, the difference in the luminance level between the image portion and the mask portion is large, as shown in FIG.
4B, the difference between the brightness levels of the image part and the mask part is small, no matter what kind of image the upper and lower mask parts have The following method is used for good detection.

First, using the data sampled as shown in FIG. 2, the luminance levels of the upper and lower mask portions are statistically obtained as follows. As shown in FIG. 5, of the upper and lower mask portions hatched with broken lines, the portions from the hatched areas with the solid lines at the upper and lower ends are extracted, and the data in these six areas are used. Here, as an example,
Since there are about 10 lines from the top and about 10 lines from the bottom and the image is divided into three in the horizontal direction, there are six regions, but the number of divisions is not limited to this. In addition, 1 from the bottom
The reason why the number of lines is about 0 is that the data of the subtitle portion is not used even in the case where the subtitle is superimposed on the lower mask portion. Since subtitles are rarely superimposed on the position of about 10 lines from the bottom, if the incoming video has upper and lower mask portions, only the data of the upper and lower mask portions without the video can be taken out. Of course, the number of upper and lower lines used for detecting the brightness levels of the upper and lower mask portions is not limited to this.

A brightness level obtained by adding a minute value considering the influence of low frequency noise to the maximum brightness level considered as the upper and lower mask portions is A, and the maximum value that each data can take is B (data 2 if is 8 bits
55), the sampling data obtained in each of the areas 1 to 5 are nonlinearly converted as shown in FIG. That is,
If the sampling data obtained in each of the areas 1 to 3 is larger than the level A, the level of the data is set to the maximum value B.
Is to be converted to. Then, in each area, if the number of pieces of data having the value B is equal to or larger than a specified value, the image is not an image having upper and lower mask portions as shown in FIG. 24, but a normal aspect ratio 4: 3. It is determined that the image is a video. In this embodiment, the data is
Since it is divided into a plurality of blocks and the number of data having the value B is confirmed in each of them, in many cases, when only an image having an aspect ratio of 4: 3 comes in, it is necessary to confirm only the data in the area. Therefore, it is detected that the image has no upper and lower mask portions, and the aspect detection is extremely fast.

Furthermore, if the number of data having the value B in each area is small and it is determined that the image has upper and lower mask portions, then the average value of the data is obtained for each area. If the average values of the data obtained in the respective areas are substantially equal to each other with a variation equal to or less than a specified value, the overall average value of all areas is obtained again, and this is determined as the brightness level of the upper and lower mask portions. In the present embodiment, the average value in each area is compared to determine whether there is variation.
If it is determined whether or not there is a variation by comparing statistics such as variance and higher moment that are obtained by subtracting the square of the average value of the data from the average value of the power, it is possible to perform more accurate determination.
Also here, if the statistical values such as the average value and the variance have a certain value or more, it is determined that the image does not have the upper and lower mask portions but the normal aspect ratio of 4: 3.

When the luminance levels of the upper and lower mask portions are determined as described above, the luminance level obtained by adding a predetermined value considering the influence of noise to the obtained luminance level of the upper and lower mask portions is C. Then, all the sampled data are binarized and converted as shown in FIG. That is, all the data sampled using the level C which is the reference value as a threshold value are compared, and as shown in FIG. Convert all data to 1. 8A and 8B are data obtained by binarizing the data shown in FIGS. 4A and 4B as shown in FIG. In the present embodiment, the sampled data is binarized and converted into 0 and 1, but the binarized value is not limited to this. For example, 0 (or minimum value) and maximum value B (data is If it is 8 bits, it may be binarized into 255). The reason for performing this binarization conversion is to increase the detection sensitivity of the boundary in the process of determining the boundary between the upper and lower mask portions and the image described below when the brightness level of the upper and lower mask portions is relatively high. As can be seen from FIGS. 8A and 8B, even if the original image is difficult to distinguish between the image portion and the mask portion, the boundary (edge) between the image portion and the mask portion becomes extremely remarkable. Edge detection becomes easy.

Then, the arithmetic circuit 5 detects the upper video start line position and the lower video end line position based on the data after the binarization conversion as follows. In the present embodiment, as described with reference to FIG. 2, eight samplings are performed in the vertical direction, so that the binarized conversion of the sampled data yields the data shown in FIG. The data shown in FIG. 10 is obtained by integrating these eight data at the same position in the horizontal direction. In addition, in FIG. 10, since the eight data are integrated, the maximum value is eight. In the integrated data shown in FIG. 10, the upper video start line position is point a and the lower video end line position is point b.

A predetermined level considering the influence of noise is set to P
Then, when data is searched from the upper part of the screen, the point a that first exceeds the level P is the upper video start line position, and when data is searched from the lower part of the screen, the point b that first exceeds the level P is the lower video end. It is the line position. The upper and lower mask portions should have been converted to 0 by the above-described binarization conversion, and even if noise is included, the level at which the image is determined is not reached. As a result of integrating the data, the noise level is at most about 1 or 2. Therefore, if the level P is set to 3, for example, the boundary between the image portion and the mask portion can be detected without being affected by the noise. it can.

By the way, the data shown in FIG. 9 is an example of sampling an image in which the upper image start line position and the lower image end line position (the boundary between the image and the upper and lower mask portions) are relatively well aligned. As shown in FIG. 11, there is an image in which the upper video start line position and the lower video end line position vary depending on the horizontal position. When the video shown in FIG. 11 is sampled and binarized and converted, the data shown in FIG. 12 is obtained. in this case,
There are variations in the rising and falling positions of each data. The data shown in FIG. 13 is obtained by integrating these eight data at the same position. Similarly, when data is searched from the upper part of the screen, the point a which first exceeds the level P is set as the upper image start line position, and data is searched from the lower part of the screen and the point b which is first exceeded the level P is the lower image. By setting the end line position, the boundary between the image portion and the mask portion can be detected.

Then, as described above, the aspect conversion circuit 6 performs the aspect conversion of the input video signal based on the analysis result of the arithmetic circuit 5. Therefore, on the tube surface of the cathode ray tube 7, the image in the range of the aspect ratio of 16: 9 at the central portion in the vertical direction is enlarged, and the display is made by fully utilizing the wide aspect.

In the first embodiment described above, as is clear from FIG. 8, the edge (the boundary between the image portion and the mask portion) is obtained by performing the binarization conversion based on the luminance levels of the upper and lower mask portions. Will become extremely prominent.
Further, since the upper video start line position and the lower video end line position are obtained using the data obtained by integrating the data after the binarization conversion as shown in FIG. 10 or FIG. Even in the case where there is not much difference between the brightness levels of the upper and lower mask parts and the brightness level of the image, the boundary between the image part and the mask part can be easily and quickly determined. Therefore, according to the present invention, it is possible to detect the aspect of the image and adjust the screen size without being affected by the brightness levels of the upper and lower mask portions.

Here, another configuration of the screen size adjusting apparatus of the present invention will be described. The screen size adjusting device of the present invention can also be configured as shown in FIG. 14, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description of the common parts will be omitted. In the configuration shown in FIG. 1 described above, the video signal such as the horizontal synchronizing signal and the vertical synchronizing signal is generated by the sync separating circuit 3, but in the configuration shown in FIG. 14, the horizontal synchronizing signal and the vertical synchronizing signal are extracted from the deflection circuit 8. , To the timing generation circuit 4. In this configuration example, since the video timing signal is obtained from the deflection circuit 8, the correct timing signal can be obtained even when the S / N of the video signal is poor and the synchronization separation is impossible, or when there is no signal and the synchronization signal disappears. It has the advantage that it can be generated and does not require a circuit for new sync separation. The operation of the other parts is exactly the same as in FIG.

Next, the structure and operation of the second embodiment will be described. The second embodiment of the screen size adjusting apparatus of the present invention has the configuration shown in FIG. 1 or FIG. 14, and the operation of the arithmetic circuit 5 is different from that of the first embodiment. In the above-described first embodiment, the case where there is a difference between the brightness level of the upper and lower mask portions and the brightness level of the video is shown. However, depending on the video, the brightness level of the upper and lower mask parts and the brightness level of the video are almost the same level. There are cases. For example, in the case of a horizontally long image having upper and lower mask portions, if the luminance levels of the upper, lower, left and right edges of the image are almost the same as the luminance levels of the upper and lower mask portions, the image is apparently shown in FIG. The image is as shown. When this video is sampled and binarized as shown in FIG. 2, the upper video start line position and the lower video end line position in each data are represented by the points shown in FIG. in this case,
The original upper video start line position and the lower video end line position are erroneously detected at the left and right edges of the video.

Therefore, it is a feature of the second embodiment to verify whether or not the upper video start line position and the lower video end line position detected at each horizontal position are correct. Data sampled at a plurality of horizontal positions as described with reference to FIG.
Divide into two areas. Then, in each of the regions 1 to 3, the upper video start line position and the lower video end line position are obtained. In this example, there are two and three regions 1 to 3, respectively.
Two upper video start addresses and two lower video end addresses are obtained. For each area, the one closer to the upper edge is determined as the upper video start line position in that area, and the one closer to the lower edge is determined. It is determined to be the lower image end line position in the area. Since the upper video start address (line number) is smaller at the upper end and the lower video end address (line number) is larger at the lower end, the upper video start line position and the lower video obtained by the sampling data of each of the regions 1 to 3 The end line positions are set as min _i and max _i (i: areas 1 to 3).

Next, of the upper image start line position and the lower image end line position in each of the regions 1 to 3,
The one closer to the upper end is determined as the upper image start line position of the entire image, and the one closer to the lower end is determined as the lower image end line position of the entire image.
That is, if this is expressed by an equation, the upper video start line position = MIN {min _i } and the lower video end line position = MAX {max _i }.

Further, the accuracy of aspect detection is calculated by the following equation. Precision = Σ | MIN {min _i } -min _i | + Σ | MAX {max _i } -max _i | (1) This precision is a non-negative integer. The smaller the value, the higher the precision, and the larger the value. The accuracy is low. For example, FIG.
Alternatively, when the upper video start line position and the lower video end line position are aligned as in the video shown in FIG. 24, the result obtained by the equation (1) is 0, which is the highest accuracy. On the other hand, in the image shown in FIG. 15, the result obtained by the equation (1) has a large value, and the accuracy of aspect detection is poor.

This accuracy is a parameter for verifying whether the upper video start line position and the lower video end line position obtained by sampling are correct. Therefore,
When the accuracy calculated by equation (1) is low (large value),
Sample the data again and perform aspect detection again. When the accuracy is high (the value is small), the aspect conversion is promptly performed according to the obtained upper video start line position and lower video end line position. That is, when the accuracy is low, the arithmetic circuit 5 does not instruct the aspect conversion circuit 6 to perform the aspect conversion. When the accuracy is high, the arithmetic circuit 5 promptly instructs the aspect conversion circuit 6 to perform the aspect conversion. Give to. This makes it possible to change the timing of operating the aspect conversion circuit 6 or switch the operation / non-operation of the aspect conversion circuit 6 according to the accuracy (variation) of aspect detection.

In the second embodiment described above, the binarization conversion is performed based on the brightness levels of the upper and lower mask portions, so that the edge (boundary between the image portion and the mask portion) becomes extremely remarkable. . Further, the screen is horizontally divided into a plurality of areas, and the upper video start line position and the lower video end line position are obtained in each area, and then the upper video start line position and the lower video end line position of the entire video image are determined. . Then, since the degree (accuracy) of the variation between the upper video start line position and the lower video end line position is obtained, it is possible to prevent the screen size from being adjusted based on erroneous aspect detection. Although the screen is divided horizontally into three regions in FIG. 17,
The number of divisions is not limited to this, and the number of samplings included in each area is not limited to this.

Next, the structure and operation of the third embodiment will be described. The screen size adjusting device according to the third embodiment of the present invention has the configuration shown in FIG. 1 or 14, and the operation of the arithmetic circuit 5 is different from that of the first and second embodiments. The third embodiment is characterized by detecting whether or not additional information such as subtitles and characters is superimposed on the upper and lower mask portions. In the following description, the case where subtitles are superimposed on the lower mask portion will be described.

As in the first embodiment, the arithmetic circuit 5 processes the data as follows when the brightness levels of the upper and lower mask parts are obtained. Similar to the first embodiment, the arithmetic circuit 5 uses the sampled data as shown in FIG. 2B as a reference, based on the level C obtained by adding a predetermined value considering the influence of noise to the luminance levels of the upper and lower mask portions. Binarization conversion is performed, and the binarized conversion data is integrated. The point at which the accumulated data is searched from the upper part of the screen toward the lower part of the screen and a predetermined level is reached is the upper image start line position. At the bottom of the screen, the point that first rises to the predetermined level is not necessarily the lower video end line position, so the point where the data was accumulated from the bottom of the screen toward the top of the screen was searched and the first level to rise to the predetermined level. After searching for, search further. If the image has subtitles in the lower mask part, as shown in FIG. 18, there are two lower video end line positions (one is the subtitle character end position and the other is the true lower video end line). Position) can be obtained.

If a pattern that rises from the black level to a predetermined level and then changes to the black level and rises again to the predetermined level is obtained, it is highly possible that the image has subtitles superimposed on the lower mask portion. The arithmetic circuit 5 is
Further, it is verified as follows whether or not the subtitles are superimposed on the lower mask part. That is, the arithmetic circuit 5 performs the ternary conversion on the data before the binary conversion as shown in FIG. The reference level C and the data sampled using the minimum brightness level D that can be said to be white instead of gray as a threshold value are compared, and as shown in FIG. 19, data having a value smaller than level C is black. The data is converted into a value α which is a level, data having a value higher than the level C and smaller than the level D is converted into a value γ which is a gray level, and data having a value larger than the level D is converted into a value β which is a white level. The value α is, for example, 0 (or the minimum value), and the value β is, for example, the maximum value (2 if the data is 8 bits).
55), and thus the value γ may be an intermediate value between these values.

The reason for performing this ternary conversion is that when a subtitle exists in the lower mask portion, there are few gray levels and many black levels and white levels in the vicinity of that subtitle, so these three values α, β , By checking the distribution of γ, it is possible to detect whether or not subtitles exist.
It is considered that only the edge portion of the character attenuated by the low-pass filter 1 has a gray level. It should be noted that the sampled data may be converted into ternary data by performing at least a portion for detecting whether or not additional information such as subtitles is superimposed, in this case, a lower mask portion of the screen. Therefore, the data accumulated from the lower part of the screen toward the upper part of the screen may be searched for, and the data in the part below the point at which the level has risen to the predetermined level the second time may be ternarized.

If the data of the image portion is ternarized, a histogram having a large frequency of the value γ is obtained as shown in FIG. 20 (B). On the other hand, the lower mask part including subtitles is shown in FIG.
As shown in 0 (A), the histogram has high frequencies of the values α and β and low frequencies of the value γ. This FIG. 20 (A),
As can be seen by comparing (B), whether or not a subtitle is present in the lower mask portion is determined by the ratio of the number of values γ to the total number (α + β + γ) of the values α, β, γ obtained by ternarization. Can be judged by As a result of ternarizing the lower mask part,
If the number of values γ is less than the predetermined reference value, it is determined that the caption is included. In this way, if it is verified that the video has the subtitles superimposed on the lower mask portion, one of the two lower video end line positions shown in FIG. It can be determined that the position is the position and the other is the lower image end line position.

Then, as described above, the aspect conversion circuit 6 performs the aspect conversion on the input video signal based on the analysis result of the arithmetic circuit 5 so that the caption is not deleted. If the aspect conversion circuit 6 includes a caption moving circuit, the video part is enlarged and displayed on the surface of the cathode ray tube 7, and the subtitle moving circuit moves the caption into the video. Good. In the present embodiment, the case where the subtitles are superimposed on the lower mask portion has been described, but it is naturally possible to detect whether or not additional information such as characters is superimposed on the upper mask portion.

Next, the structure and operation of the fourth embodiment will be described. The fourth embodiment of the screen size adjusting device of the present invention has the configuration shown in FIG. 1 or 14, and the operation of the arithmetic circuit 5 is different from that of the first to third embodiments. Similar to the third embodiment, the fourth embodiment is characterized by detecting whether or not additional information such as subtitles and characters is superimposed on the upper and lower mask portions. In the following description, a case where characters are superimposed on the upper mask part will be described.

The arithmetic circuit 5 displays an image in which characters such as time display are superimposed on the upper mask portion as shown in FIG.
Sampling as described in. Then, as in the first embodiment, when the luminance levels of the upper and lower mask portions are obtained, the sampled data is added to the luminance level of the upper and lower mask portions with a predetermined value in consideration of the influence of noise, and level 2 is used as a reference. Convert to value. When the video as shown in FIG. 21 is sampled and binarized and converted, the data as shown in FIG. 22 is obtained. The data shown in FIG. 23 is obtained by integrating these eight data in the same position in the horizontal direction. In addition, in FIG. 23, since the eight data are integrated, the maximum value is eight.

A predetermined level considering the influence of noise is set to P
Then, when data is searched from the upper part of the screen, the point a that first exceeds the level P is the upper video start line position, and when data is searched from the lower part of the screen, the point b that first exceeds the level P is the lower video end. It is the line position. The level P is 3
Alternatively, it may be set appropriately as in 4. Further, the data is searched from the upper part of the screen, and the point having a non-zero value is set as c first. If the distance δ between the points c and a is longer than a specified value, it is determined that the image has additional information such as characters superimposed on the upper mask portion. This is c
This is because if the point and the point a are extremely close to each other, there is a high possibility that they are due to edge variation as shown in FIG. 13 or noise.

Then, as described above, the aspect conversion circuit 6 performs the aspect conversion of the input video signal based on the analysis result of the arithmetic circuit 5. At this time, the aspect conversion circuit 6 can perform the aspect conversion so that the characters superimposed on the upper mask portion are not deleted. If the aspect conversion circuit 6 includes a subtitle moving circuit, the video portion is enlarged and displayed on the surface of the cathode ray tube 7, and the subtitle moving circuit performs aspect conversion to move the character in the image. Good. In the present embodiment, the case where characters are superimposed on the upper mask portion has been described, but it is naturally possible to detect whether or not additional information such as subtitles is superimposed on the lower mask portion.

[0041]

As described in detail above, the screen size adjusting device of the present invention has the following effects due to the following structure. (1) First means for detecting the luminance levels of the upper and lower mask portions in the arithmetic circuit, and digital sampling based on a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. A second means for binarizing the data into a first value and a second value; and
Means for integrating the digital data binarized by the means in the horizontal direction, and detecting a point where the digital data integrated by the third means exceeds a predetermined level to start the upper image. By including the fourth means for obtaining the line position and the lower video end line position, it is possible that the luminance level of the upper and lower mask portions is high or there is not much difference between the luminance level of the upper and lower mask portions and the luminance level of the image. Even in such a case, the boundary between the image portion and the mask portion can be easily and quickly determined.

(2) In the arithmetic circuit, the first means for detecting the luminance levels of the upper and lower mask portions, and a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means are used as references. Second means for binarizing and converting the sampled digital data into a first value and a second value, and a plurality of regions in which the digital data binarized by the second means are arranged in the horizontal direction of the screen. Third means for determining the upper image start line position in the region closer to the upper end and determining the lower image end line position in the region closer to the lower end in each region And, of the upper image start line position and the lower image end line position in each area obtained by the third means, the one closer to the upper end is the entire image. Fourth means for determining the upper image start line position and determining the one closer to the lower end as the lower image end line position for the entire image, and the upper image start in each region obtained by the third means Fifth means for obtaining the variations between the line position and the lower video end line position and the upper video start line position and the lower video end line position for the entire video obtained by the fourth means, and the fifth means. By including the sixth means for operating the aspect conversion circuit in accordance with the obtained variation, when the luminance level of the upper and lower mask portions is high, or there is not much difference between the luminance level of the upper and lower mask portions and the luminance level of the image. Even if it does not exist, the boundary between the image part and the mask part can be distinguished easily and at high speed. It is possible to prevent the adjustment of the screen size based on the defect detection.

(3) In the arithmetic circuit, the first means for detecting the luminance levels of the upper and lower mask portions, and a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means are used as references. Second means for binarizing and converting the sampled digital data into a first value and a second value, and an upper image start line position and a position based on the digital data binarized and converted by the second means. Third means for determining the lower image end line position, and at least a part of the sampled digital data are used as first to third values.
And a fifth means for detecting whether or not the additional information is superimposed on the upper and lower mask portions based on the data ternarized and converted by the fourth means. With the above configuration, even when the luminance level of the upper and lower mask portions is high or there is not much difference between the luminance level of the upper and lower mask portions and the luminance level of the image, It is possible to easily and quickly determine the boundary, and it is possible to accurately determine whether or not the additional information is superimposed on the upper and lower mask portions.

(4) The arithmetic circuit has a first means for detecting the luminance levels of the upper and lower mask portions and a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. Second means for binarizing and converting the sampled digital data into a first value and a second value, and a third means for horizontally integrating the digital data binarized and converted by the second means. Means and fourth means for obtaining an upper video start line position and a lower video end line position by detecting a point where the digital data accumulated by the third means exceeds a predetermined level, and the accumulated digital data Detect a point having a level smaller than a predetermined level and not 0 from the vertical end of the data to the position of the upper video start line or the lower video end line. Additional information is added to the upper and lower mask portions by detecting the distance between the upper image start line position or the lower image end line position and the point having a non-zero level obtained by the fifth means. By including the sixth means for detecting whether or not they are superposed, when the luminance level of the upper and lower mask portions is high or there is not much difference between the luminance level of the upper and lower mask portions and the luminance level of the image. Even in this case, it is possible to easily and quickly determine the boundary between the image portion and the mask portion, and it is possible to accurately determine whether or not the additional information is superimposed on the upper and lower mask portions. .

[Brief description of drawings]

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

FIG. 2 is a diagram for explaining a video data capturing method according to the present invention.

FIG. 3 is a waveform chart showing an example of sampling data according to the present invention.

FIG. 4 is a waveform diagram for explaining the operation of the present invention.

FIG. 5 is a diagram for explaining the operation of the present invention.

FIG. 6 is a diagram for explaining the operation of the present invention.

FIG. 7 is a diagram for explaining the operation of the present invention.

FIG. 8 is a waveform diagram for explaining the operation of the present invention.

FIG. 9 is a diagram for explaining the operation of the first exemplary embodiment of the present invention.

FIG. 10 is a diagram for explaining the operation of the first embodiment of the present invention.

FIG. 11 is a diagram showing an example of an image in which a boundary between a video image and upper and lower mask portions varies.

FIG. 12 is a diagram for explaining the operation of the first embodiment of the present invention.

FIG. 13 is a diagram for explaining the operation of the first embodiment of the present invention.

FIG. 14 is a block diagram showing another configuration of the present invention.

FIG. 15 is a diagram showing an example of an image in which it is difficult to determine the boundary between the video and the upper and lower mask portions.

16 is a diagram showing a result of sampling the image shown in FIG.

FIG. 17 is a diagram for explaining the operation of the second embodiment of the present invention.

FIG. 18 is a diagram showing an example of an image in which a caption is superimposed on a lower mask portion.

FIG. 19 is a diagram for explaining the operation of the third embodiment of the present invention.

FIG. 20 is a diagram for explaining the operation of the third embodiment of the present invention.

FIG. 21 is a diagram showing an example of an image in which characters are superimposed on an upper mask portion.

FIG. 22 is a diagram for explaining the operation of the fourth exemplary embodiment of the present invention.

FIG. 23 is a diagram for explaining the operation of the fourth embodiment of the present invention.

FIG. 24 is a diagram showing a horizontally long image in which upper and lower portions are masked.

FIG. 25 is a diagram showing a display example on a television receiver having an aspect ratio of 16: 9.

[Explanation of symbols]

 1 Low-pass filter 2 A / D conversion circuit 3 Synchronization separation circuit 4 Timing generating circuit 5 Operation circuit 6 Aspect conversion circuit 7 CRT 8 Deflection circuit

Claims (4)

[Claims] 1. A screen size adjusting apparatus for determining the presence or absence of upper and lower mask portions in an incoming video signal and their positions, and adjusting a screen size according to the image, wherein a high frequency component of the incoming video signal is removed. A low-pass filter, an A / D conversion circuit that converts the video signal output from the low-pass filter into digital data, and the digital data output from the A / D conversion circuit according to a data capture timing signal to a predetermined horizontal position. An arithmetic circuit for detecting the upper and lower mask portions by taking in one or a plurality of fields so as to become a plurality of horizontal positions over one field in the vertical direction, and the incoming video signal based on the detection result of the arithmetic circuit. And an aspect conversion circuit for performing aspect conversion on the upper and lower mask portions in the arithmetic circuit. Means for detecting the luminance level of the digital data, and a first reference value and a second reference value for the digital data with reference to a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. Second means for binarizing and converting the values into digital values, third means for horizontally integrating the digital data binarized and converted by the second means, and digital data integrated by the third means A screen size adjusting device, comprising: a fourth means for determining an upper video start line position and a lower video end line position by detecting a point where data exceeds a predetermined level. 2. A screen size adjusting device for determining the presence or absence of upper and lower mask portions in an incoming video signal and their positions, and adjusting the screen size according to the image, wherein a high frequency component of the incoming video signal is removed. A low-pass filter, an A / D conversion circuit that converts the video signal output from the low-pass filter into digital data, and the digital data output from the A / D conversion circuit according to a data capture timing signal to a predetermined horizontal position. An arithmetic circuit for detecting the upper and lower mask portions by taking in one or a plurality of fields so as to become a plurality of horizontal positions over one field in the vertical direction, and the incoming video signal based on the detection result of the arithmetic circuit. And an aspect conversion circuit for performing aspect conversion on the upper and lower mask portions in the arithmetic circuit. Means for detecting the luminance level of the digital data, and a first reference value and a second reference value for the digital data with reference to a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. Second means for binarizing and converting the data into digital values and digital data binarized and converted by the second means are divided into a plurality of areas in the horizontal direction of the screen, and each area is closer to the upper end. A third means for determining an object as an upper image start line position in the area, and an object closer to the lower end as a lower image end line position in the area; and each of the third means obtained by the third means. Of the upper image start line position and the lower image end line position in the area, the one closer to the upper end is determined as the upper image start line position for the entire image and Fourth means for determining a position close to the part as a lower image end line position of the entire image; an upper image start line position and a lower image end line position in each region obtained by the third means; 5 means for obtaining a variation between the upper video start line position and the lower video end line position for the entire video image obtained by the fourth aspect, and the aspect conversion circuit according to the variation obtained by the fifth aspect. And a sixth means for operating the screen size adjusting device. 3. A screen size adjusting device for determining the presence or absence of upper and lower mask portions in an incoming video signal and their positions, and adjusting a screen size according to the image, wherein a high frequency component of the incoming video signal is removed. A low-pass filter, an A / D conversion circuit that converts the video signal output from the low-pass filter into digital data, and the digital data output from the A / D conversion circuit according to a data capture timing signal to a predetermined horizontal position. An arithmetic circuit for detecting the upper and lower mask portions by taking in one or a plurality of fields so as to become a plurality of horizontal positions over one field in the vertical direction, and the incoming video signal based on the detection result of the arithmetic circuit. And an aspect conversion circuit for performing aspect conversion on the upper and lower mask portions in the arithmetic circuit. Means for detecting the luminance level of the digital data, and a first reference value and a second reference value for the digital data with reference to a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. A second means for binarizing and converting the value into a value, and a third means for obtaining an upper video start line position and a lower video end line position based on the digital data binarized by the second means, Fourth means for ternarizing and converting at least a part of the digital data obtained by the A / D conversion circuit into a first value to a third value, and ternarized conversion by the fourth means. And a fifth means for detecting whether or not the additional information is superimposed on the upper and lower mask portions based on the data. 4. A screen size adjusting device for determining the presence or absence of upper and lower mask portions and their positions in an incoming video signal and adjusting the screen size according to the image, wherein a high frequency component of the incoming video signal is removed. A low-pass filter, an A / D conversion circuit that converts the video signal output from the low-pass filter into digital data, and the digital data output from the A / D conversion circuit according to a data capture timing signal to a predetermined horizontal position. An arithmetic circuit for detecting the upper and lower mask portions by taking in one or a plurality of fields so as to become a plurality of horizontal positions over one field in the vertical direction, and the incoming video signal based on the detection result of the arithmetic circuit. And an aspect conversion circuit for performing aspect conversion on the upper and lower mask portions in the arithmetic circuit. Means for detecting the luminance level of the digital data, and a first reference value and a second reference value for the digital data with reference to a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. Second means for binarizing and converting the values into digital values, third means for horizontally integrating the digital data binarized and converted by the second means, and digital data integrated by the third means Fourth means for obtaining the upper image start line position and the lower image end line position by detecting a point where the data exceeds a predetermined level, and the upper image start from the vertical end of the integrated digital data. A fifth means for detecting a point having a level smaller than the predetermined level and not being 0 up to the line position or the lower image end line position; and the fifth means. By detecting the distance between the obtained point having a non-zero level and the upper video start line position or the lower video end line position, it is detected whether or not additional information is superimposed on the upper and lower mask portions. A screen size adjusting device comprising: a sixth means.