JPH0818884A - Image size adjustment device and method for detecting aspect ratio - Google Patents

Abstract

PURPOSE:To provide an image size adjustment device in which upper and lower mask parts are detected with high accuracy and its image is displayed on a video image display section in an optimizing state. CONSTITUTION:A low pass filter 1 eliminates a high frequency video signal into digital data. A synchronizing separator circuit 3 separates a synchronizing signal from the video signal and a timing generating circuit 4 gives a timing signal to an arithmetic circuit 5. The arithmetic circuit 5 receives plural fields of data at a prescribed horizontal position to be plural horizontal positions over one field in the vertical direction. Then a luminance level of upper and lower mask parts is detected based on the data and the data are nonlinearly converted based on the luminance level. Based on the data after nonlinear conversion, an upper part video image start line position and a lower part video end line position are obtained. As a result, an aspect ratio conversion circuit 6 is operated in the case of a laterally long image and the 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 adjustment device and an aspect detection method suitable for a television receiver having an image display unit (CRT, etc.) and having an aspect conversion circuit. TECHNICAL FIELD The present invention relates to a screen size adjustment device and an aspect detection method that can automatically determine whether or not a horizontally long image with a portion masked and display the image in an optimal state on a video display unit without the viewer performing complicated operations. .

[0002]

2. Description of the Related Art Recently, a television receiver (hereinafter referred to as wide TV) equipped with a wide aspect image display section having an aspect ratio of 16: 9 has been introduced, and is shown as an image source in FIG. 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.
If it is displayed on V as it is, it becomes a horizontally elongated image as shown in FIG. 16 (A), but if the viewer manually sets the aspect conversion, as shown in FIG. 16 (B), the vertical center where the image exists is displayed. 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 for each video source or are not necessarily constant, 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 section 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 aspect detection method according to the prior art, 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. In such a case, it becomes difficult to detect the boundary (edge) between the mask portion and the image. Therefore, in the conventional screen size adjusting device, it takes time to detect the boundary and the screen displayed on the image display unit is displayed. There is a problem in that it takes a long time to adjust the size, which may give the viewer a feeling of strangeness. The present invention has been made in view of the above problems, and it is possible to detect the upper and lower mask portions with high accuracy and display the image in an optimal state on the video display unit without the viewer performing complicated operations. It is an object of the present invention to provide a screen size adjustment device and an aspect detection method that can be performed.

[0006]

In order to solve the above-mentioned problems of the prior art, the present invention (A) determines the presence or absence and the position of upper and lower mask portions in an incoming video signal, and according to the image. In a screen size adjusting device for adjusting a screen size, a low-pass filter for removing a high frequency component of the incoming video signal, an A / D conversion circuit for converting a video signal output from the low-pass filter into digital data, The A /
An arithmetic circuit for detecting the upper and lower mask portions by fetching the digital data output from the D conversion circuit 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 a aspect conversion circuit for aspect-converting the incoming video signal based on the detection result of the arithmetic circuit, and (1) the arithmetic circuit detects a luminance level of the upper and lower mask portions. Means and second means for nonlinearly converting the digital data with reference to a predetermined reference value based on the brightness levels of the upper and lower mask portions detected by the first means, and the data after the nonlinear conversion A screen size adjustment characterized by being configured to obtain the upper video start line position and the lower video end line position based on Provides a device, first detecting the (2) to the arithmetic circuit, the luminance level of said upper and lower mask portions
Means and a second means for comparing the digital data with a predetermined reference value based on the brightness levels of the upper and lower mask portions detected by the first means, and the comparison by the second means. Provided is a screen size adjusting device, which is configured to obtain an upper video start line position and a lower video end line position based on a result,
(3) 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 and converting the digital data into a first value and a second value is provided, and the upper video start line position and the lower video end line position are based on the data after the binary conversion. There is provided a screen size adjusting device characterized in that

Further, in order to solve the above-mentioned problems of the prior art, (B) it is detected whether the incoming video signal is an image having upper and lower mask portions, and if it is an image having upper and lower mask portions. An aspect detection method for detecting the upper video start line position and the lower video end line position,
(1) A first step of capturing one or a plurality of fields of the incoming video signal data in a vertical direction at a predetermined horizontal position so as to be a plurality of horizontal positions over one field, and among the captured data A second step of checking the luminance levels of the data at the upper and lower end portions of the screen to determine whether or not the upper and lower mask portions are present, and the luminance level of the upper and lower end portions of the screen when it is determined to have the upper and lower mask portions. Based on the non-linearly converted data, and a fourth step of non-linearly converting all the acquired data with reference to a predetermined reference value based on the detected brightness level. Provided is an aspect detection method, which comprises a fifth step of obtaining an upper video start line position and a lower video end line position, and (2) before. A first step of fetching data of an incoming video signal for one or a plurality of fields so that it becomes a plurality of horizontal positions vertically over one field at a predetermined horizontal position; and among the fetched data, upper and lower edges of the screen A second step of checking the luminance level of the data of the set to determine whether or not the upper and lower mask portions are present; The third step, a fourth step of comparing a predetermined reference value based on the detected brightness level with all the acquired data, and the fourth step.
The aspect detection method is characterized by comprising a fifth step of obtaining an upper video start line position and a lower video end line position based on the comparison result of the step of (3), A first step of capturing data for one or a plurality of fields so that data becomes a plurality of horizontal positions vertically over one field at a predetermined horizontal position, and the brightness level of the data at the upper and lower ends of the screen among the captured data. And a third step of determining whether the upper and lower mask portions are present, and a third step of detecting the brightness levels of the upper and lower end portions of the screen when it is determined that the upper and lower mask portions are included. A fourth binarization conversion is performed on all of the captured data with a predetermined reference value based on the detected brightness level as a reference into a first value and a second value. Step and is intended to provide an aspect wherein providing more becomes possible a fifth step of obtaining an upper image start line position and the lower video end line position based the binarized transformed data.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A screen size adjusting device and an aspect detecting method of the present invention will be described below with reference to the accompanying drawings. 1 is a block diagram showing a configuration of a screen size adjusting apparatus of the present invention, FIG. 2 is a view for explaining a screen data adjusting method by the screen size adjusting apparatus and the aspect detecting method of the present invention, and FIG. 3 is a screen of the present invention. A waveform diagram showing an example of sampling data by the size adjusting device and the aspect detecting method, FIG. 4 is a waveform diagram for explaining the operation of the screen size adjusting device and the aspect detecting method of the present invention, and FIGS. FIG. 7 is a diagram for explaining the operation of the screen size adjusting device and the aspect detecting method, FIG. 7 is a diagram for explaining the operation of the first embodiment of the screen size adjusting device and the aspect detecting method of the present invention, and FIG. 8 is the present invention. For explaining address projection by the screen size adjusting device and aspect detecting method of FIG. 9, and FIGS. 9 and 10 are the screen size adjusting device and aspect of the present invention. Waveform diagram for explaining the operation of the first embodiment of the detection method, FIG. 11 is a block diagram showing another configuration of the screen size adjustment apparatus of the present invention, and FIG. 12 is a screen size adjustment apparatus and aspect detection method of the present invention. FIG. 13 is a waveform diagram for explaining the operation of the second embodiment of the screen size adjusting apparatus and aspect detection method of the present invention, and FIG. 14 is the screen of the present invention. It is a figure for demonstrating operation | movement of 2nd Example of a size adjustment apparatus and an aspect detection method.

First, the structure and operation of the first embodiment shown in FIG. 1 will be described. In FIG. 1, the incoming video signal is input to a low pass filter 1, a sync separation circuit 3, and an 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 constituting the mask portion in the image is a low frequency component, so that the high frequency component is unnecessary for detecting the mask portion, and 0 to 800 kH of the video signal.
This is because it is sufficient to sample the low frequency component of z. Further, the low-pass filter 1 removes pulse noise due to random noise or sparks, because many noise components intermingle when the S / N of the video signal is bad.
At the same time plays a role of preventing erroneous detection
The conversion circuit 2 also has a role of being able to use an inexpensive one with a low sampling frequency. Since the required frequency component is low, even if the incoming video signal is a composite signal, the color component superimposed at 3.58 MHz in NTSC 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.

As a result of the operation 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. ), 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 for realizing the aspect detection method 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 whole screen is divided into eight parts in the horizontal direction as in the present embodiment, eight fields are required until the sampling of the whole screen is completed. Of course, you can narrow or widen this division width,
If the arithmetic circuit 5 has a high capacity 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. 15, 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 to 4C, 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. 15, 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, non-linear conversion is applied to all the sampled data as shown in FIG. Assuming that the luminance level obtained by adding a predetermined value considering the influence of noise to the obtained luminance levels of the upper and lower mask portions is C, as shown in FIG. It is converted to 0 (or the minimum value). FIG. 4C is data obtained by non-linearly converting the data shown in FIG. 4B, which is difficult to distinguish between the image portion and the mask portion, as shown in FIG. The reason for this non-linear transformation is
This is because when the brightness level of the upper and lower mask portions is relatively high, the detection sensitivity of the boundary between the upper and lower mask portions and the image, which will be described below, is increased. FIG.
As can be seen from (C), 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 conspicuous, and the 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 non-linear conversion. The arithmetic circuit 5 scans the data stored in the memory as shown in FIG. 4C above the scanning line (left in the drawing).
And the lower part of the scanning line (right in the figure) are searched at the same time to find the address of the line position which rises above a predetermined level. When the horizontal direction is sampled in 8 divisions as described above, eight upper video start addresses and lower video end addresses (if subtitles are superimposed on the lower mask part,
(In addition, the subtitle start address and subtitle end address)
Can be obtained.

As a result, as shown in FIG. 8, the upper video start address is 120, the lower video end address is 400 at the horizontal position (1), and the upper video start address is 120 at the horizontal position (2). The lower video end address is 400, the upper video start address is 126 at the horizontal position (7), the lower video end address is 411, and the upper video start address is 12 at the horizontal position (8).
Eight data can be obtained such that 0 and the lower video end address are 400. Therefore, give a number such as "1" to each position where these addresses are obtained,
These eight data are added. Hereinafter, this will be referred to as address projection.

As a result of this address projection, the obtained data shows a normal distribution, all the data are the same, or the screen is switched between 8 fields and there is no upper or lower mask part. Is projected in completely disjointed positions. Finally, the maximum value of this projected data is set as the upper video line start position and the lower video line end position, but if the maximum value is not a majority, the position information is invalid and sampling is performed again. calculate. From the above, the upper video line start position and the lower video line end position are obtained. 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, the aspect ratio of the central portion in the vertical direction is 1 on the surface of the cathode ray tube 7.
The image in the range of 6: 9 is enlarged, and the display is made by fully utilizing the wide aspect.

As a further preferred embodiment, the data shown in FIG. 4 (C) after the non-linear conversion is processed as follows to make the edges more prominent and detect the upper video start line position and the lower video end line position. You may That is,
The arithmetic circuit 5 processes the data as follows. First, the data after the non-linear conversion is differentiated in the vertical direction (vertical direction), and the difference between lines (the amount of change in the line direction) is calculated as shown in FIG. This is because the mask part has no change in the image, and thus the energy is lost by differentiating. Since this does not always provide a sufficient boundary, the differential data shown in FIG. 9 (A) is squared as shown in FIG. 9 (B) in order to more reliably determine the boundary. In this way, by differentiating the captured vertical data and further squaring it, the boundary can be more easily discriminated. A /
In the case where a sufficient dynamic range can be secured for the video signal input by the D conversion circuit 2 and the boundary can be easily discriminated, the differential data is used instead of the squaring as shown in FIG. 9C. You may only make it an absolute value.

FIG. 10 shows a waveform obtained by subjecting the non-linearly converted data shown in FIG. 4 (C) to (differential + square) processing. As is clear from FIG. 10, after performing the non-linear conversion based on the luminance levels of the upper and lower mask portions (differential + 2
By performing the processing of (multiplication), the edge (the boundary between the image portion and the mask portion) becomes more prominent. If the upper video line start position and the lower video line end position are obtained by performing the address projection as described above using the data shown in FIG. 10, when the brightness level of the upper and lower mask portions is high or the brightness level of the upper and lower mask portions is high. Even if there is not much difference between the luminance level of the image and the luminance level of the image, the boundary between the image portion and the mask portion can be more easily discriminated. 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.

Next, another configuration and operation of the first embodiment shown in FIG. 11 will be described. In FIG. 11, the incoming video signal includes a low-pass filter 1 and an aspect conversion circuit 6
Is input to 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 configuring the mask portion in the image is a low frequency component, so that the high frequency component is unnecessary for detecting the mask portion, and if the low frequency component of 0 to 800 kHz is sampled in the video signal, Because it is enough. 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, the color component superimposed at 3.58 MHz in NTSC 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.

In the configuration shown in FIG. 1 described above, the video timing signals such as the horizontal synchronizing signal and the vertical synchronizing signal are generated by the sync separating circuit 3. However, in the configuration shown in FIG. 11, the horizontal synchronizing signal and the vertical synchronizing signal are generated by the deflection circuit 8. The signal is taken out and supplied to the timing generation circuit 4. As described above, in the second embodiment, since the video timing signal is obtained from the deflection circuit 8, even when the S / N of the video signal is bad and the sync separation is impossible, or when there is no signal and the sync signal disappears. It is possible to generate the correct timing signal, and
There is an advantage that a circuit for new sync separation is not required. 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 by the take-in timing signal, analyzes the video data by the above-mentioned method, and the incoming video signal masks the upper and lower parts. It is determined whether the image is a landscape image. 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 supply the timing signal for fetching the video data to the arithmetic circuit 5. However, when the same fetch control can be performed by the horizontal synchronizing signal and the vertical synchronizing signal inside the arithmetic circuit 5, Timing generation circuit 4
Is not always necessary.

As a result of the operation circuit 5 analyzing the video data as in FIG. 1, the incoming video signal has an aspect ratio of 4: 3 as shown in FIG. When it is determined that the image is a landscape image having an aspect ratio of 16: 9, the arithmetic circuit 5 instructs the aspect conversion circuit 6 to perform the aspect conversion as shown in FIG. 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. Therefore, even if the S / N is deteriorated and the sync signal is difficult to separate on the tube surface of the cathode ray tube 7, an image whose aspect is converted to an optimum state for the incoming video signal is displayed. It

Next, the structure and operation of the second embodiment will be described. The configuration of the second embodiment is either the configuration of FIG. 1 or FIG. 11, and the second embodiment differs from the first embodiment in the operation (aspect detection method) in the arithmetic circuit 5. Therefore, the operation of the arithmetic circuit 5 will be mainly described.

In FIG. 1 or FIG. 11, the arithmetic circuit 5
In the same manner as in the first embodiment, as shown in FIG. 2, the image data is taken in so that it becomes a plurality of horizontal positions in the vertical direction of the screen.
Then, similarly to the first embodiment, the luminance levels of the upper and lower mask portions are statistically obtained using the sampled data.
That is, as shown in FIG. 5, of the upper and lower mask portions, the areas 1 to 3 are extracted and the data in these 6 areas are used. Here, as an example, since there are about 10 lines from the top and about 10 lines from the bottom, and three regions are divided in the horizontal direction, there are six regions, but the number of divisions is not limited to this. It should be noted that the reason for setting about 10 lines from the bottom is to prevent the data of the subtitle portion from being 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.

The brightness level obtained by adding a minute value in consideration of 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. 15, 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.

Further, when the number of data having the value B in each area is small and it is determined that the image has the upper and lower mask portions, the average value of the data is calculated 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. The brightness level C is used as a reference value, and the reference value C and all sampled data are compared. The upper video start line position is the position at which the data having a value smaller than the reference value C is switched to the data having a larger value, and conversely the position at which the data having a value larger than the reference value C is switched to the data having a smaller value. It is determined that it is the lower image end line position. The number of pieces of data having a value smaller than the reference value C and the number of pieces of data having a value larger than the reference value C are counted. If it is determined that it is, it is possible to prevent erroneous detection without being affected by noise. Further, in the present embodiment, the reference level C is a brightness level obtained by adding a predetermined value to the brightness levels of the upper and lower mask portions, but the reference value is not limited to this.

As a further preferred embodiment of the second embodiment, the data is processed as follows. When the brightness levels of the upper and lower mask portions are determined, a brightness level obtained by adding a predetermined value considering the influence of noise to the obtained brightness levels 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.
(Or the minimum value) and all the data having a value larger than the level C is the maximum value B (25 bits if the data is 8 bits).
Convert to 5). 13 (A) and 13 (B) are shown in FIG.
The data shown in FIG. 12B is binarized and converted as shown in FIG. 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. FIG. 13 (A),
As can be seen from (B), even if it is difficult to distinguish the image part and the mask part in the original image, the boundary (edge) between the image part and the mask part becomes extremely noticeable, and the 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 binarization conversion. The arithmetic circuit 5 simultaneously retrieves the data stored in the memory as shown in FIGS. 13A and 13B from the upper part of the scanning line (left in the drawing) and the lower part of the scanning line (right in the drawing), and a predetermined level or more is retrieved. Find the address of the line position that has risen to. As shown in FIG. 14, the upper video start line position has a boundary at the position where the value 0 changes to the value B of the pattern for switching from the M value 0 data to the N value B data. Contrary to FIG. 14, the image end line position is determined to be the boundary at the position where the value B changes to the value 0 in the pattern in which the data of N values B is switched to the data of M values 0. . These M and N deal with the fact that a similar pattern is accidentally generated by noise.
It is desirable that M and N> 3. When the horizontal direction is sampled in 8 divisions as described above, eight upper video start addresses and lower video end addresses (if subtitles are superimposed on the lower mask part, in addition to them, subtitle start addresses and subtitle end addresses Can also get).

As a result, as shown in FIG. 8, the upper video start address is 120 and the lower video end address is 400 at the horizontal position (1), and the upper video start address is 120 at the horizontal position (2). The lower video end address is 400, the upper video start address is 126 at the horizontal position (7), the lower video end address is 411, and the upper video start address is 12 at the horizontal position (8).
Eight data can be obtained such that 0 and the lower video end address are 400. Therefore, give a number such as "1" to each position where these addresses are obtained,
Address projection is performed by adding these eight data.

As a result of the address projection, the obtained data shows a normal distribution, all the data match, or the screen is switched between 8 fields to form an image without upper and lower mask portions. Is projected in completely disjointed positions. Finally, the maximum value of this projected data is set as the upper video line start position and the lower video line end position, but if the maximum value is not a majority, the position information is invalid and sampling is performed again. calculate. From the above, the upper video line start position and the lower video line end position are obtained. 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, the aspect ratio of the central portion in the vertical direction is 1 on the surface of the cathode ray tube 7.
The image in the range of 6: 9 is enlarged, and the display is made by fully utilizing the wide aspect.

In the second embodiment described above, as is apparent from FIG. 13, 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. Therefore, in the second embodiment, since it is not necessary to perform the (differential + square) processing, the arithmetic processing by the arithmetic circuit 5 can be simple and the processing time is short. If the upper video line start position and the lower video line end position are obtained by performing address projection as described above using the data shown in FIG. 13, when the brightness level of the upper and lower mask portions is high or the brightness level of the upper and lower mask portions is high. Even if there is not much difference between the luminance level of the image and the luminance level of the image, the boundary between the image portion and the mask portion can be more easily discriminated. 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.

[0037]

As described in detail above, the screen size adjusting device of the present invention has the following effects due to the following structure. (1) In the arithmetic circuit, first means for detecting the luminance levels of the upper and lower mask portions, and non-linear conversion of data with reference to a reference value based on the luminance levels of the upper and lower mask portions detected by the first means. The second means is provided, and the upper image start line position and the lower image end line position are obtained based on the data after the non-linear conversion. Therefore, the entire screen is dark, and the image portion and the mask are taken with the captured data as it is. Even if it is difficult to distinguish the boundary with the part, it is possible to accurately distinguish the boundary. Therefore, the viewer can display the horizontally long image with the upper and lower portions masked in the optimum state on the video display unit without performing complicated operations. (2) In particular, as a second means, if the data and the reference value are compared and the data of the level smaller than the reference value is converted to 0 or the minimum value, the boundary becomes conspicuous and the image portion The boundary with the mask portion can be accurately determined. (3) Further, there is provided a third means for differentiating the data in the vertical direction and squaring the differentiated data or converting the differentiated data into an absolute value, and the upper video start line is based on the data processed by the third means. By determining the position and the lower image end line position, the boundary becomes more prominent, and the boundary between the image portion and the mask portion can be accurately discriminated.

(4) Further, 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. A second means for comparing with the data is provided, and the upper image start line position and the lower image end line position are obtained based on the comparison result by the second means. Even if it is difficult to distinguish the boundary between the image part and the mask part, the data can be accurately distinguished. Therefore, the viewer can display the horizontally long image with the upper and lower portions masked in the optimum state on the video display unit without performing complicated operations. (5) Further, the arithmetic circuit is configured to detect the luminance levels of the upper and lower mask portions, and data based on a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. And a second means for binarizing and converting the above into a first value and a second value, and an upper video start line position and a lower video end line position are obtained based on the data after the binarization. Since it is configured, even if the entire screen is dark and it is difficult to determine the boundary between the image portion and the mask portion with the captured data as it is, the determination can be performed more accurately. Therefore, the viewer can display the horizontally long image with the upper and lower portions masked in the optimum state on the video display unit without performing complicated operations. (6) In particular, as the second means in (5), the data and the reference value are compared, data having a level smaller than the reference value is converted to 0 or the minimum value, and data larger than the reference value is the maximum value. If converted to, the boundary between the image portion and the mask portion becomes extremely conspicuous, and the boundary can be accurately discriminated. In this case, the arithmetic processing by the arithmetic circuit may be simple and the processing time is short. (7) Further, if the data fetch timing signal input to the arithmetic circuit is generated from the horizontal sync signal and the vertical sync signal output from the deflection circuit, the S / N of the video signal is deteriorated and the sync signal is Even if it is difficult to separate, it has a feature that it can operate stably and does not require a new circuit for synchronization separation.

On the other hand, the aspect detection method of the present invention has the following effects due to the following configuration. (8) The first step of capturing one or more fields of the incoming video signal data in a plurality of horizontal positions vertically over one field at a predetermined horizontal position, and a screen of the captured data The second step of checking the luminance levels of the data at the upper and lower ends to determine whether or not the upper and lower mask portions are present, and detecting the luminance levels at the upper and lower end portions of the screen when it is determined to have the upper and lower mask portions A third step, a fourth step of performing a non-linear conversion of all the data taken in with a reference value based on the detected brightness level as a reference, and an upper video start line position and a lower video based on the non-linearly converted data. Since the fifth step of obtaining the end line position is performed, when the luminance level of the upper and lower mask portions is high, or the luminance level of the upper and lower mask portions and the luminance of the image Even when the there is little difference between the bell, it is possible to easily determine the boundary between the image portion and the mask portion, it is an aspect detection not affected by the luminance level of the upper and lower mask portions. (9) Further, between the fourth step and the fifth step, there is provided a sixth step of differentiating the non-linearly transformed data in the vertical direction and further squaring the differential data or converting it into an absolute value. If so, the boundary between the image portion and the mask portion becomes more prominent, and highly accurate aspect detection can be performed. (10) In particular, as a fourth step, if the reference value and the data are compared and the data of the level smaller than the reference value is converted to 0 or the minimum value, the boundary between the image portion and the mask portion is remarkable. The boundary can be accurately determined.

(11) Furthermore, the first step of fetching the data of the incoming video signal for one or a plurality of fields so that it becomes a plurality of horizontal positions vertically over one field at a predetermined horizontal position, and is fetched. Of the data, the second step of checking the luminance level of the data at the upper and lower end portions of the screen to determine whether or not the upper and lower mask portions are present; Based on a third step of detecting a brightness level, a fourth step of comparing a predetermined reference value based on the detected brightness level with all the captured data, and a comparison result of the fourth step. It includes the fifth step of obtaining the upper video start line position and the lower video end line position. Even if there is not much difference between the brightness level and the video brightness level, the boundary between the video part and the mask part can be easily discriminated, and the aspect detection is not affected by the brightness levels of the upper and lower mask parts. You can (12) Also, the first step of capturing the data of the incoming video signal for one or a plurality of fields so that it becomes a plurality of horizontal positions vertically over one field at a predetermined horizontal position, and the upper and lower sides of the captured data. A second step of checking the luminance level of the edge portion to determine whether or not it has upper and lower mask portions, and a third step of detecting the luminance level of the upper and lower edge portions of the screen when it is determined to have the upper and lower mask portions. A step, and a fourth step of binarizing and converting all the data taken in with a reference value based on the detected brightness level into a first value and a second value, and binarized and converted. Since the fifth step of obtaining the upper video start line position and the lower video end line position based on the data is performed, when the brightness level of the upper and lower mask parts is high or the brightness level of the upper and lower mask parts is high. Even if there is not much difference between the brightness level of the image and the brightness level of the image, it is possible to more easily distinguish the boundary between the image part and the mask part, and aspect detection that is not affected by the brightness levels of the upper and lower mask parts can be performed. it can. (13) In particular, as the fourth step in (12), the reference value and the data are compared, data of a level smaller than the reference value is converted to 0 or a minimum value, and data larger than the reference value is converted to a maximum value. If so, the boundary between the image portion and the mask portion becomes extremely remarkable, and the boundary can be accurately discriminated. In this case, the arithmetic processing by the arithmetic circuit may be simple and the processing time is short. (14) As the above second and third steps, if the upper and lower end portions of the screen are divided into a plurality of blocks and the brightness level is checked in each block or the brightness level is detected in each block, It is possible to quickly and accurately detect whether or not the incoming video signal is a video having 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 first embodiment of the present invention.

FIG. 8 is a diagram for explaining address projection according to the present invention.

FIG. 9 is a waveform chart for explaining the operation of the first embodiment of the present invention.

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

FIG. 11 is a block diagram showing another configuration of the present invention.

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

FIG. 13 is a waveform chart for explaining the operation of the second embodiment of the present invention.

FIG. 14 is a diagram for explaining the operation of the second embodiment of the present invention.

FIG. 15 is a diagram showing a horizontally long image in which upper and lower portions are masked.

FIG. 16 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 (14)

[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 that converts the aspect ratio of the First means for detecting the brightness level of the mask portion and second means for nonlinearly converting the digital data with reference to a predetermined reference value based on the brightness levels of the upper and lower mask portions detected by the first means. And a means for determining the upper video start line position and the lower video end line position based on the non-linearly converted data. 2. The second means compares the digital data with the reference value and converts data of a level smaller than the reference value into 0 or a minimum value. 1. The screen size adjusting device described in 1. 3. The arithmetic circuit is provided with a third means for differentiating the digital data after the non-linear conversion at the respective horizontal positions in the vertical direction and squaring the differential data or converting the differential data into an absolute value. 3. The screen size adjusting device according to claim 1 or 2, wherein the upper image start line position and the lower image end line position are obtained based on the data processed by the third means. 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 that converts the aspect ratio of the First means for detecting the luminance level of the mask portion, and second means for comparing the digital data with a predetermined reference value based on the luminance levels of the upper and lower mask portions detected by the first means. And a screen size adjusting device characterized in that the upper image start line position and the lower image end line position are obtained based on the comparison result by the second means. 5. 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 that converts the aspect ratio of the First means for detecting the brightness level of the mask portion, and a predetermined reference value based on the brightness levels of the upper and lower mask portions detected by the first means as a reference, and the digital data as a first value and a first value. Two
And a second means for performing a binarization conversion to the value of and the upper video start line position and the bottom video end line position are obtained based on the data after the binarization conversion. Size adjustment device. 6. The second means compares the digital data with the reference value, converts data of a level smaller than the reference value into 0 or a minimum value, and converts data larger than the reference value into a maximum value. The screen size adjusting device according to claim 5, wherein 7. The screen size adjusting device according to claim 6, wherein the data acquisition timing signal is generated from a horizontal synchronizing signal and a vertical synchronizing signal output from a deflection circuit. . 8. An aspect for detecting whether or not an incoming video signal is an image having upper and lower mask portions, and for an image having upper and lower mask portions, detecting an upper image start line position and a lower image end line position. A first step of capturing one or more fields of the incoming video signal data in a vertical direction at a predetermined horizontal position over one field to a plurality of horizontal positions; and the captured data. Of the above, the second step of checking the luminance level of the data at the upper and lower end portions of the screen to determine whether or not the upper and lower mask portions are present; A third step of detecting a brightness level, and a non-linear transformation of all the acquired data with reference to a predetermined reference value based on the detected brightness level. An aspect detecting method comprising: a fourth step of converting the upper image start line position and a lower image end line position based on the non-linearly converted data. 9. A sixth differential between the fourth step and the fifth step, wherein the non-linearly transformed data is vertically differentiated, and the differential data is squared or made into an absolute value. 9. The aspect detection method according to claim 8, further comprising: 10. The fourth step is to compare the digital data with the reference value and convert data having a level smaller than the reference value to 0 or a minimum value. 10. The aspect detection method according to either 8 or 9. 11. An aspect for detecting whether or not an incoming video signal is a video having upper and lower mask portions, and for an image having upper and lower mask portions, detecting an upper video start line position and a lower video end line position. A first step of capturing one or more fields of the incoming video signal data in a vertical direction at a predetermined horizontal position over one field to a plurality of horizontal positions; and the captured data. Of the above, the second step of checking the luminance level of the data at the upper and lower end portions of the screen to determine whether or not the upper and lower mask portions are present; A third step of detecting a brightness level, and a fourth step of comparing a predetermined reference value based on the detected brightness level with all the acquired data. An aspect detection method comprising: a step; and a fifth step of obtaining an upper image start line position and a lower image end line position based on the comparison result of the fourth step. 12. An aspect for detecting whether an incoming video signal is an image having upper and lower mask portions, and detecting an upper image start line position and a lower image end line position if the image signal has upper and lower mask portions. A first step of capturing one or more fields of the incoming video signal data in a vertical direction at a predetermined horizontal position over one field to a plurality of horizontal positions; and the captured data. Of the above, the second step of checking the luminance level of the data at the upper and lower end portions of the screen to determine whether or not the upper and lower mask portions are present; A third step of detecting a brightness level, and a first step of converting all the acquired data with a predetermined reference value based on the detected brightness level as a reference. Value and second
And a fifth step of obtaining an upper video start line position and a lower video end line position based on the binarized data. Aspect detection method. 13. The fourth step compares the digital data with the reference value, converts data of a level smaller than the reference value into 0 or a minimum value, and converts data larger than the reference value into a maximum value. 13. The aspect detection method according to claim 12, wherein the aspect ratio is converted into. 14. The second and third steps are for dividing the upper and lower end portions of the screen into a plurality of blocks, and checking the brightness level or detecting the brightness level in each block. Claims 8 to 1
4. The aspect detection method according to any one of 3 above.