JP3144226B2 - Screen size adjustment device and aspect detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aspect ratio of 16: 9.
The present invention relates to a screen size adjustment device and an aspect detection method suitable for use in a television receiver having an image display section (such as a cathode ray tube) and an aspect conversion circuit. The present invention relates to a screen size adjustment device and an aspect detection method capable of automatically determining whether or not an image is a landscape image in which a part is masked and displaying the image in an optimal state on a video display unit without a viewer performing complicated operations. .

[0002]

2. Description of the Related Art Recently, a television receiver (hereinafter, referred to as a wide TV) equipped with a 16: 9 aspect ratio wide-screen image display section has appeared. As described above, various sources having different aspect ratios (vertical size), such as a Vista source having an aspect ratio of 4: 3 but having non-image portions (mask portions) in upper and lower portions, are provided. It has become

An image source as shown in FIG.
If the image is displayed as it is on the V, the image becomes a horizontally elongated image as shown in FIG. 16A. However, if the viewer manually sets the aspect conversion, as shown in FIG. The image in the range of the aspect ratio of 16: 9 is enlarged, and a display that makes full use of the wide-aspect image display unit can be performed.

As described above, in the conventional wide TV, when displaying a video source such as a movie in which the upper and lower portions are masked, the viewer must manually operate the aspect conversion. Since the width of the upper and lower mask portions varies from one video source to another or is not always constant, the above aspect conversion requires an extremely complicated operation. Therefore, it is automatically determined whether the video signal is a horizontal image with the upper and lower parts masked, and the screen size is adjusted so that the viewer can display the image in an optimal state on the video display unit without performing complicated operations. A device has been developed, and a wide TV equipped with the device has appeared.

[0005]

However, in the aspect detection method according to the prior art, when the brightness level of the upper and lower mask portions is high or the brightness level of the upper and lower mask portions does not significantly differ from the brightness level of the image. In such a case, it becomes difficult to detect the boundary (edge) between the mask portion and the image, and in the conventional screen size adjusting device, it takes time to detect the boundary, and the screen displayed on the image display unit takes a long time. There has been a problem in that the time until the size is adjusted becomes longer, and the viewer may feel uncomfortable. The present invention has been made in view of such a problem, and can accurately detect upper and lower mask portions, and display the image in an optimal state on a video display unit without a viewer performing complicated operations. It is an object of the present invention to provide a screen size adjustment device and an aspect detection method capable of performing the above operation.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention (A) obtains the presence / absence and position of upper and lower mask portions in an incoming video signal, and 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 / A
An arithmetic circuit for detecting the upper and lower mask portions by capturing the digital data output from the D conversion circuit in one or more fields so as to be at a plurality of horizontal positions over one field in a vertical direction at a predetermined horizontal position; An aspect conversion circuit for aspect-converting the incoming video signal based on a detection result of the arithmetic circuit; and (1) a first circuit for detecting a luminance level of the upper and lower mask portions in the arithmetic circuit. Means, and second means for non-linearly converting the digital data with reference to a predetermined reference value based on the luminance level of the upper and lower mask portions detected by the first means. Screen size adjustment wherein the upper image start line position and the lower image end line position are obtained 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 second means for comparing the digital data with a predetermined reference value based on the luminance level of the upper and lower mask portions detected by the first means, Providing a screen size adjustment device characterized by being configured to determine the upper image start line position and the lower image end line position based on the result,
(3) A first means for detecting the brightness level of the upper and lower mask portions in the arithmetic circuit, and a predetermined reference value based on the brightness level of the upper and lower mask portions detected by the first means. Second means for binarizing and converting the digital data into a first value and a second value, wherein an upper image start line position and a lower image end line position are determined based on the binarized data. Is provided so as to obtain a screen size adjustment device.

Further, in order to solve the above-mentioned problems of the prior art, (B) it is detected whether or not an 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 an upper image start line position and a lower image end line position,
(1) a first step of capturing one or more fields of the incoming video signal so as to be at a plurality of horizontal positions over one field in a vertical direction at a predetermined horizontal position; A second step of checking the brightness level of the data at the upper and lower ends of the screen to determine whether or not the screen has upper and lower mask portions; A fourth step of performing a non-linear conversion of all the acquired data with reference to a predetermined reference value based on the detected luminance level, and a third step of performing a non-linear conversion based on the non-linearly converted data. A fifth step of obtaining an upper image start line position and a lower image end line position. A first step of capturing data of an incoming video signal by one or more fields so as to be at a plurality of horizontal positions over one field in a vertical direction at a predetermined horizontal position; A second step of checking the brightness level of the data of the portion and determining whether or not the upper and lower mask portions are provided; and A fourth step of comparing a predetermined reference value based on the detected luminance level with all of the acquired data;
A fifth step of obtaining an upper image start line position and a lower image end line position based on the comparison result obtained in the steps (a) to (c). A first step of fetching data for one or a plurality of fields in a predetermined horizontal position at a plurality of horizontal positions over one field in a vertical direction, and, among the fetched data, a luminance level of data at an upper and lower end of a screen; A second step of determining whether or not there is an upper and lower mask portion by confirming, and a third step of detecting a luminance level at the upper and lower ends of the screen when it is determined that the screen has an upper and lower mask portion; A fourth method of binarizing and converting all the acquired data into a first value and a second value based on a predetermined reference value based on the detected luminance level; 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]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A screen size adjusting apparatus and an aspect detecting method according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of a screen size adjusting device according to the present invention, FIG. 2 is a diagram for explaining a video data capturing method using the screen size adjusting device and the aspect detection method according to the present invention, and FIG. FIG. 4 is a waveform diagram showing an example of sampling data obtained by the size adjustment device and the aspect detection method, FIG. 4 is a waveform diagram for explaining the operation of the screen size adjustment device and the aspect detection method of the present invention, and FIGS. FIG. 7 is a diagram for explaining the operation of the screen size adjustment device and the aspect detection method, FIG. 7 is a diagram for explaining the operation of the first embodiment of the screen size adjustment device and the aspect detection method of the present invention, and FIG. FIG. 9 and FIG. 10 are diagrams for explaining address projection by the screen size adjusting device and aspect detection method of the present invention. FIG. 11 is a 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 device of the present invention, and FIG. 12 is a screen size adjustment device and aspect detection method of the present invention. FIG. 13 is a diagram for explaining the operation of the second embodiment of the present invention, FIG. 13 is a waveform diagram for explaining the operation of the second embodiment of the screen size adjusting device and the aspect detection method of the present invention, and FIG. FIG. 9 is a diagram for explaining the operation of the second embodiment of the size adjustment device and the aspect detection method.

First, the configuration and operation of the first embodiment shown in FIG. 1 will be described. In FIG. 1, an 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 high-frequency components of the input video signal and inputs the same 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.
This is because it is sufficient to sample the low frequency component of z. Further, the low-pass filter 1 removes random noise and pulse-like noise due to sparks because many noise components are mixed when the S / N of the video signal is poor.
At the same time as the role of preventing erroneous detection, the A / D
The conversion circuit 2 also plays a role that an inexpensive one with a low sampling frequency can be used. 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, and only the luminance component simply passes. Therefore, an 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 synchronization separation circuit 3 separates a synchronization signal from the input video signal and supplies a timing generation circuit 4 with video timing signals such as a horizontal synchronization signal and a vertical synchronization signal. The timing generation circuit 4 supplies a capture timing signal for capturing video data to the arithmetic circuit 5. The arithmetic circuit 5 captures the video data converted into a digital signal by the A / D conversion circuit 2 based on the capture timing signal, analyzes the video data by a method described in detail later, and determines whether the incoming video signal is up or down. It is determined whether or not the image is a landscape image in which a portion is masked. Note 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 arithmetic circuit 5 using the timing generation circuit 4 is used.
The timing generation circuit 4 is not always necessary when the same capture control can be performed by the horizontal synchronization signal and the vertical synchronization signal inside the arithmetic circuit 5.

Then, as a result of the analysis of the video data by the arithmetic circuit 5, the incoming video signal is shown in FIG.
If it is determined that the image is a landscape image having an aspect ratio of 4: 3 as shown in FIG. 5 but an image having an aspect ratio of 16: 9 at the center in the vertical direction, the arithmetic circuit 5 sends the image shown in FIG. ) To perform the aspect conversion as shown in ()). The aspect conversion circuit 6 converts the aspect of the input video signal in accordance with the instruction and supplies it to the CRT 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 operating at least one of the horizontal and vertical deflection widths. Therefore, an image whose aspect has been converted into an optimum state for the incoming video signal is displayed on the surface of the cathode ray tube 7.

Here, 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 video data will be described. As shown in FIG. 2, first, the arithmetic circuit 5 captures video data over one field in the vertical direction of the screen at a predetermined horizontal position (1) according to the capture timing specified by the timing generation circuit 4. In the next field, the horizontal position is delayed backward, the video data is similarly captured at the horizontal position (2), and thereafter, similarly to the final horizontal position (8), the horizontal start position (1) Return to. As described above, if the operation of capturing the video data is continuously performed until the sampling in the horizontal direction of the screen is completed, the data of the entire screen is obtained. When the entire screen is divided into eight in the horizontal direction as in this embodiment, eight fields are required until sampling of the entire screen is completed. Of course, this division width may be narrowed or widened,
If the capacity of the arithmetic circuit 5 is high and the memory is abundant, the entire screen may be sampled simultaneously.

If the incoming video signal is a video with the top and bottom masked as shown in FIG. 15, the vertical digital data captured as described above has a waveform as shown in FIG. 3A, for example. . In this case, the upper image start line position and the lower image end line position may be detected. In addition, 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. In the following description, FIG.
Such an image will be described as an example.

FIG. 4A 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 sampling data when the luminance level of the mask portion is high and it is difficult to distinguish the video portion from 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. According to the present invention, FIG.
4B, the difference between the luminance level of the video part and the luminance level of the mask part is small. 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, from the upper and lower mask portions hatched by broken lines, the regions to which hatching is applied by solid lines at the upper and lower ends are extracted, and data in these six regions is used. Here, as an example,
Approximately 10 lines from the top and approximately 10 lines from the bottom are divided into three in the horizontal direction, so that the area is six, 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 to prevent the data of the subtitle portion from being used even in the case of a video in which the subtitle is superimposed on the lower mask portion. Since subtitles are rarely superimposed at about 10 lines from the bottom, if the incoming video has upper and lower mask portions, only data of the upper and lower mask portions without video can be extracted. Of course, the number of upper and lower lines used for detecting the luminance level of the upper and lower mask portions is not limited to this.

The luminance level obtained by adding the maximum value of the luminance level considered as the upper and lower mask portions to a minute value considering the influence of low frequency noise is defined as A, and the maximum value that can be taken by each data is defined as B (data Is 8 bits, 2
55), and the sampling data obtained in each of the areas (1) to (6) is nonlinearly transformed as shown in FIG. That is,
If the sampling data obtained in each of the areas 1 to 5 is larger than the level A, the level of the data is set to the maximum value B
Is converted to If the number of data having the value B in each area is equal to or more than a specified value, the image is not an image having upper and lower mask portions as shown in FIG. It is determined that the image is the same. In the present embodiment, the data is
Since the data is divided into a plurality of blocks and the number of data each having the value B is checked, when an image having an aspect ratio of 4: 3 comes in, it is often necessary to check only the data in the area. As a result, an image having no upper and lower mask portions is detected, and the aspect detection is extremely fast.

Further, if it is determined that the number of pieces of data having the value B in each area is small and the image has upper and lower mask portions, then an average value of data is obtained for each area. If the average values of the data obtained in the respective regions are substantially equal to each other with a variation of less than a predetermined value, a total average value of all the regions is newly obtained, and is determined as the luminance level of the upper and lower mask portions. In this embodiment, the average value in each area is compared to determine whether there is a variation.
If the statistic of variance or higher moment, which is obtained by subtracting the square of the average value of the data from the average value of the power, is compared to determine whether there is a variation, more accurate determination can be made.
Here, if the statistics such as the average value and the variance have a variation equal to or more than a predetermined value, it is determined that the image is not an image having upper and lower mask portions but an image having a normal aspect ratio of 4: 3.

When the brightness levels of the upper and lower mask portions are determined as described above, all the sampled data are subjected to nonlinear conversion as shown in FIG. Assuming that a luminance level obtained by adding a predetermined value in consideration of 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 performing non-linear conversion on the data shown in FIG. 4B as shown in FIG. The reason for performing this nonlinear transformation is
This is because when the luminance 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 described below is determined in the process of obtaining the boundary. FIG.
As can be seen from (C), even if the original video is difficult to distinguish between the video portion and the mask portion, the boundary (edge) between the video portion and the mask portion becomes prominent, and the edge detection becomes easy.

The arithmetic circuit 5 detects an upper video start line position and a lower video end line position based on the data after the non-linear conversion. The arithmetic circuit 5 stores the data as shown in FIG. 4C stored in the memory in the upper part of the scanning line (left in the figure).
And from the lower part of the scanning line (right side in the figure) at the same time, and the address of the line position rising above a predetermined level is obtained. As described above, when sampling is performed by dividing the horizontal direction into eight, the eight upper video start addresses and the lower video end addresses (if subtitles are superimposed on the lower mask portion,
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 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 as 0, the lower video end address is 400. Therefore, a number “1” is given to each position where these addresses are obtained,
These eight data are added. Hereinafter, this is referred to as address projection.

If, as a result of the address projection, the obtained data shows a normal distribution, all the data match, or the image is switched between eight fields and the image is changed to an image without upper and lower mask portions. Are projected to completely separate locations. Finally, the maximum value of the projected data is defined as the upper video line start position and the lower video line end position.If the maximum value cannot be obtained by a majority, the position information is invalidated and sampling is performed again. calculate. As described above, the start position of the upper video line and the end position of the lower video line are obtained. 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. 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 a display that makes full use of the wide aspect is displayed.

In a further preferred embodiment, the data shown in FIG. 4C after the non-linear conversion is processed as follows to make the edges more prominent and to detect the upper image start line position and the lower image end line position. It may be. That is,
The data is processed in the arithmetic circuit 5 as follows. First, the data after the nonlinear 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 to take advantage of the fact that the mask portion has no change in image and therefore loses energy by differentiating. In this case, a sufficient boundary is not always obtained, so that the differential data shown in FIG. 9A is squared as shown in FIG. 9B in order to more reliably determine the boundary. In this way, by differentiating the captured vertical data and further squaring, the boundary can be more easily determined. A /
In the case where a sufficient dynamic range can be ensured for the video signal input to the D conversion circuit 2 and the boundary can be easily determined, the differential data is obtained instead of performing the square as shown in FIG. Only the absolute value may be used.

FIG. 10 shows a waveform obtained by performing (differential + square) processing on the data subjected to the non-linear conversion shown in FIG. 4 (C). 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 (power), edges (boundaries between the video portion and the mask portion) appear more remarkably. Then, the address projection is performed using the data shown in FIG. 10 as described above to determine the start position of the upper video line and the end position of the lower video line. Even if there is not much difference between the image portion and the brightness level of the image, the boundary between the image portion and the mask portion can be more easily determined. Therefore, according to the present invention, image aspect detection and screen size adjustment can be performed 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, an incoming video signal is a low-pass filter 1, an aspect conversion circuit 6
Is input to The low-pass filter 1 removes high-frequency components of the input video signal and inputs the same to the A / D conversion circuit 2.
This is because the high frequency component is unnecessary for detecting the mask portion since the frequency constituting the mask portion in the image is a low frequency component, and if the low frequency component of 0 to 800 kHz is sampled in the video signal, Because it is enough. When the S / N ratio of the video signal is low, the low-pass filter 1 removes random noise and pulse-like noise due to sparks to prevent erroneous detection. The latter A / D conversion circuit 2 also plays a role of using a low-cost A / D conversion circuit 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, and only the luminance component simply passes. Therefore, an 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 synchronization separation circuit 3 generates video timing signals such as a horizontal synchronization signal and a vertical synchronization signal. In the configuration shown in FIG. The signal is extracted 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 poor and synchronization separation is impossible, or when there is no signal and the synchronization signal disappears, the second embodiment does not. It is possible to generate the correct timing signal,
There is an advantage that a new circuit for synchronization separation is not required. The timing generation circuit 4 supplies a capture timing signal for capturing video data to the arithmetic circuit 5. Then, the arithmetic circuit 5 captures the video data converted into the digital signal by the A / D conversion circuit 2 according to the capture timing signal, analyzes the video data by the above-described method, and masks the upper and lower portions of the incoming video signal. It is determined whether the image is a landscape image. Note that a microcomputer can be used as the arithmetic circuit 5. In this case, there is no problem even if the A / D conversion circuit 2 has a built-in microcomputer. In this case, the timing generation circuit 4 is used to supply a video data capture timing signal to the arithmetic circuit 5. However, if similar capture control can be performed inside the arithmetic circuit 5 by the horizontal synchronization signal and the vertical synchronization signal, Timing generation circuit 4
Is not necessary.

The arithmetic circuit 5 analyzes the video data in the same manner as in FIG. 1, and as a result, the incoming video signal has an aspect ratio of 4: 3 as shown in FIG. If the arithmetic circuit 5 determines that the image is a landscape image in which an image having an aspect ratio of 16: 9 exists, the arithmetic circuit 5 instructs the aspect conversion circuit 6 to perform aspect conversion as shown in FIG. The aspect conversion circuit 6 converts the aspect of the input video signal in accordance with the instruction and supplies it to the CRT 7. Therefore, even when the S / N is deteriorated and the synchronization signal is difficult to be separated, an image whose aspect has been converted into an optimum state for the incoming video signal is displayed on the surface of the CRT 7. You.

Next, the configuration 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 operation (aspect detection method) in the arithmetic circuit 5 of the second embodiment is different from that of the first embodiment. Therefore, the operation of the arithmetic circuit 5 will be mainly described.

In FIG. 1 or FIG.
Captures video data at a plurality of horizontal positions in the vertical direction of the screen as shown in FIG. 2, as in the first embodiment.
Then, the luminance levels of the upper and lower mask portions are statistically obtained using the sampled data as in the first embodiment.
That is, as shown in FIG. 5, the region (1) is extracted from the upper and lower mask portions, and data in these six regions is used. Here, as an example, about 10 lines from the top and about 10 lines from the bottom are divided into three in the horizontal direction, so that the area is six, but the number of divisions is not limited to this. The reason why the number of lines is about 10 lines from the bottom is to prevent the data of the subtitle portion from being used even in the case of a video in which the subtitle is superimposed on the lower mask portion. Since subtitles are rarely superimposed at about 10 lines from the bottom, if the incoming video has upper and lower mask portions, only data of the upper and lower mask portions without video can be extracted. Of course, the number of upper and lower lines used for detecting the luminance level of the upper and lower mask portions is not limited to this.

The luminance level obtained by adding the maximum value of the luminance level considered as the upper and lower mask portions to a minute value in consideration of the influence of low frequency noise is represented by A, and the maximum value of each data can be represented by B (data Is 8 bits, 2
55), and the sampling data obtained in each of the areas (1) to (6) is nonlinearly transformed as shown in FIG. That is,
If the sampling data obtained in each of the areas 1 to 5 is larger than the level A, the level of the data is set to the maximum value B
Is converted to If the number of data having the value B in each area is equal to or more than a specified value, the image is not an image having upper and lower mask portions as shown in FIG. It is determined that the image is the same. In the present embodiment, the data is
Since the data is divided into a plurality of blocks and the number of data each having the value B is checked, when an image having an aspect ratio of 4: 3 comes in, it is often necessary to check only the data in the area. As a result, an image having no upper and lower mask portions is detected, and the aspect detection is extremely fast.

Further, if it is determined that the number of data having the value B in each area is small and the image has upper and lower mask portions, then an average value of data is obtained for each area. If the average values of the data obtained in the respective regions are substantially equal to each other with a variation of less than a predetermined value, a total average value of all the regions is newly obtained, and is determined as the luminance level of the upper and lower mask portions. In this embodiment, the average value in each area is compared to determine whether there is a variation.
If the statistic of variance or higher moment, which is obtained by subtracting the square of the average value of the data from the average value of the power, is compared to determine whether there is a variation, more accurate determination can be made.
Here, if the statistics such as the average value and the variance have a variation equal to or more than a predetermined value, it is determined that the image is not an image having upper and lower mask portions but an image having a normal aspect ratio of 4: 3.

When the luminance levels of the upper and lower mask portions are determined as described above, a 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 defined as C. The luminance level C is used as a reference value, and the reference value C is compared with all the sampled data. The position at which the data having a value smaller than the reference value C is switched to the data having a larger value is the upper image start line position, and the position at which the data having the value greater than the reference value C is changed to the data having a smaller value is conversely. It is determined that this is the lower video end line position. The number of data having a value smaller than the reference value C and the number of data having a value larger than the reference value C are counted. If the number of the data is equal to or more than a certain value, the upper image start line position and the lower image end line position. Is determined, the influence of noise can be prevented, and erroneous detection can be prevented. Further, in the present embodiment, the luminance level obtained by adding a predetermined value to the luminance level of the upper and lower mask portions is used as the reference value C, but the reference value is not limited to this.

As a further preferred embodiment of the second embodiment, 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 in consideration of the influence of noise to the obtained brightness levels of the upper and lower mask portions is set to C. Then, binarization conversion is performed on all the sampled data as shown in FIG. That is, all data sampled using the reference level C as a threshold value are compared with each other, and as shown in FIG.
(Or the minimum value), and all data having a value greater than the level C are converted to the maximum value B (25 bits if the data is 8 bits).
Convert to 5). FIGS. 13A and 13B are FIGS.
This is data obtained by binarizing the data shown in FIG. 12B as shown in FIG. The reason for performing this binarization conversion is to increase the detection sensitivity of the boundary between the upper and lower mask portions and the video in the process of obtaining the boundary when the luminance level of the upper and lower mask portions is relatively high, as described below. FIG. 13 (A),
As can be seen from (B), even if the original video is such that the video portion and the mask portion are difficult to distinguish, the boundary (edge) between the video portion and the mask portion becomes extremely noticeable, and the edge detection becomes easy. .

Then, the arithmetic circuit 5 detects an upper image start line position and a lower image end line position based on the data after the binarization conversion. The arithmetic circuit 5 simultaneously searches the data as shown in FIGS. 13A and 13B stored in the memory from the upper part of the scanning line (left in the figure) and the lower part of the scanning line (right in the figure), and a predetermined level or more. Find the address of the line position that has risen. As shown in FIG. 14, the upper image start line position is a boundary where the position at which the pattern changes from M value 0 data to N value B data, from value 0 to value B, is lower. The video end line position is determined to be a boundary where the position where the value B changes from the value B to the value 0 in the pattern of switching from the data of the N values B to the data of the value 0 is contrary to FIG. . These M and N are used to cope with a case where a similar pattern is accidentally generated by noise.
It is desirable that M, N> 3. As described above, when sampling is performed by dividing the horizontal direction into eight, the eight upper video start addresses and the lower video end addresses (if a subtitle is superimposed on the lower mask portion, the subtitle start address and the subtitle end address are additionally provided). Also).

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 as 0, the lower video end address is 400. Therefore, a number “1” is given to each position where these addresses are obtained,
The address projection is performed by adding these eight data.

As a result of the address projection, if the obtained data shows a normal distribution, all the data match, or the image is switched between eight fields and the image is changed to an image without upper and lower mask portions. Are projected to completely separate locations. Finally, the maximum value of the projected data is defined as the upper video line start position and the lower video line end position.If the maximum value cannot be obtained by a majority, the position information is invalidated and sampling is performed again. calculate. As described above, the start position of the upper video line and the end position of the lower video line are obtained. 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. 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 a display that makes full use of the wide aspect is displayed.

In the second embodiment described above, as apparent from FIG. 13, the edge (the boundary between the video portion and the mask portion) is obtained by performing the binarization conversion based on the luminance levels of the upper and lower mask portions. Becomes very noticeable. Therefore, in the second embodiment, since there is no need to perform (differential + square) processing, the arithmetic processing by the arithmetic circuit 5 can be simple and the processing time is short. Then, the address projection is performed as described above using the data shown in FIG. 13 to determine the start position of the upper video line and the end position of the lower video line. Even if there is not much difference between the image portion and the brightness level of the image, the boundary between the image portion and the mask portion can be more easily determined. Therefore, according to the present invention, image aspect detection and screen size adjustment can be performed without being affected by the brightness levels of the upper and lower mask portions.

[0037]

As described in detail above, the screen size adjusting apparatus of the present invention has the following effects by the following configuration. (1) A first means for detecting the luminance level of the upper and lower mask portions in the arithmetic circuit and non-linear conversion of the data based on a reference value based on the luminance level of the upper and lower mask portions detected by the first means. 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. Even when it is difficult to determine the boundary with the part, it can be accurately determined. Therefore, the viewer can display the landscape image in which the upper and lower portions are masked in an optimal state on the video display unit without performing complicated operations. (2) In particular, as a second means, if data is compared with a reference value and data at a level smaller than the reference value is converted to 0 or a minimum value, the boundary becomes noticeable and the image portion is 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 differential data or converting the data into an absolute value. Based on the data processed by the third means, an upper image start line is provided. If the position and the lower image end line position are determined, the boundary becomes more prominent, and the boundary between the image portion and the mask portion can be accurately determined.

(4) A first means for detecting the brightness level of the upper and lower mask portions, a predetermined reference value based on the brightness level of the upper and lower mask portions detected by the first means, and And second means for comparing the data with the data, and the upper image start line position and the lower image end line position are determined based on the comparison result by the second means. With this data, accurate determination can be made even when it is difficult to determine the boundary between the video portion and the mask portion. Therefore, the viewer can display the landscape image in which the upper and lower portions are masked in an optimal state on the video display unit without performing complicated operations. (5) The arithmetic circuit includes: first means for detecting 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 the upper image into a first value and a second value, and calculating the upper image start line position and the lower image end line position based on the binarized data. With this configuration, even when the entire screen is dark and it is difficult to determine the boundary between the video portion and the mask portion with the captured data as it is, it is possible to more accurately determine the boundary. Therefore, the viewer can display the landscape image in which the upper and lower portions are masked in an optimal state on the video display unit without performing complicated operations. (6) In particular, as a second means in (5), data is compared with a reference value, 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. In this case, the boundary between the video portion and the mask portion becomes extremely noticeable, and the boundary can be accurately determined. 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 synchronization signal and the vertical synchronization signal output from the deflection circuit, the S / N of the video signal deteriorates and the synchronization signal becomes It has the advantage that it can be operated stably even in cases where it is difficult to separate, and does not require a new circuit for synchronizing separation.

On the other hand, the aspect detection method of the present invention has the following effects by the following configuration. (8) A first step of capturing one or more fields of incoming video signal data at a predetermined horizontal position in a vertical direction at a plurality of horizontal positions over one field, and, among the captured data, a screen A second step of checking the brightness level of the data at the upper and lower ends to determine whether or not the image has upper and lower mask portions; A third step, a fourth step of non-linearly converting all data acquired based on a reference value based on the detected luminance level, and an upper image start line position and a lower image based on the non-linearly converted data. Since the fifth step for obtaining the end line position is performed, when the luminance level of the upper and lower mask portions is high, or when the luminance level of the upper and lower mask portions is higher 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 converted data in the vertical direction and further squaring or converting the differential data to an absolute value. Then, the boundary between the video portion and the mask portion becomes more remarkable, and highly accurate aspect detection can be performed. (10) In particular, if the reference value and the data are compared as the fourth step and data of a level smaller than the reference value is converted to 0 or the minimum value, the boundary between the video portion and the mask portion is remarkable. And the boundary can be accurately determined.

(11) Further, a first step of taking in one or more fields of incoming video signal data so as to be at a plurality of horizontal positions over one field in a vertical direction at a predetermined horizontal position, and The second step of checking the brightness level of the data at the upper and lower ends of the screen among the data to determine whether or not the upper and lower mask portions are provided. A third step of detecting a luminance level, a fourth step of comparing a predetermined reference value based on the detected luminance level with all the acquired data, and a step of comparing the result of the fourth step. The fifth step for obtaining the upper image start line position and the lower image end line position is performed when the brightness level of the upper and lower mask portions is high or when the upper and lower mask portions Even when there is not much difference between the luminance level and the luminance level of the image, the boundary between the image part and the mask part can be easily determined, and the aspect detection is not affected by the luminance levels of the upper and lower mask parts. Can be. (12) Also, a first step of capturing one or more fields of incoming video signal data at a predetermined horizontal position in a vertical direction at a plurality of horizontal positions over one field; A second step of checking the brightness level of the end portion to determine whether or not to have the upper and lower mask portions, and a third step of detecting the brightness level of the upper and lower end portions of the screen when it is determined to have the upper and lower mask portions A step, a fourth step of binarizing all the data taken in with reference to a reference value based on the detected luminance level into a first value and a second value, and a binarized conversion The fifth step is to obtain the upper image start line position and the lower image end line position based on the data. Even if there is not much difference between the image level and the image luminance level, the boundary between the image part and the mask part can be more easily determined, and the aspect detection that is not affected by the luminance levels of the upper and lower mask parts can be performed. it can. (13) In particular, as a fourth step in (12), the reference value and the data are compared, and data at a level lower 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. In this case, the boundary between the image portion and the mask portion becomes extremely noticeable, and the boundary can be accurately determined. 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 ends of the screen are divided into a plurality of blocks and the luminance level is confirmed in each block, or the processing of detecting the luminance level in each block is performed, It is possible to quickly and accurately detect whether or not an incoming video signal is an image having upper and lower mask portions.

[Brief description of the 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 diagram showing an example of sampling data according to the present invention.

FIG. 4 is a waveform chart 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 landscape image in which upper and lower portions are masked.

FIG. 16 is a diagram illustrating a display example by a television receiver having an aspect ratio of 16: 9.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low-pass filter 2 A / D conversion circuit 3 Synchronization separation circuit 4 Timing generation circuit 5 Arithmetic circuit 6 Aspect conversion circuit 7 CRT 8 Deflection circuit

Claims (14)

(57) [Claims] 1. A screen size adjusting apparatus for determining the presence or absence and position of upper and lower mask portions in an incoming video signal and adjusting the screen size according to the image, wherein the high frequency component of the incoming video signal is removed. A digital signal output from the A / D conversion circuit in response to a data capture timing signal; and a low-pass filter that converts the video signal output from the low-pass filter into digital data. An arithmetic circuit for detecting the upper and lower mask portions by capturing one or more fields so as to be at a plurality of horizontal positions over one field in the vertical direction, and the incoming video signal based on a detection result of the arithmetic circuit. And an aspect conversion circuit for performing an aspect conversion of the image data. First means for detecting a luminance level of a mask portion; and second means for non-linearly converting the digital data with reference to a predetermined reference value based on the luminance level of the upper and lower mask portions detected by the first means. Means for determining an upper image start line position and a lower image end line position based on the data after the non-linear conversion. 2. The apparatus according to claim 1, wherein said second means compares said digital data with said reference value and converts data of a level smaller than said reference value to 0 or a minimum value. The screen size adjustment device according to 1. 3. The arithmetic circuit is provided with third means for differentiating the digital data after the non-linear conversion at the respective horizontal positions in the vertical direction, and squaring or converting the differential data to an absolute value, 3. The screen size adjusting device according to claim 1, wherein an upper image start line position and a lower image end line position are obtained based on the data processed by the third means. 4. A screen size adjusting apparatus for determining the presence or absence and position of upper and lower mask portions 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 digital signal output from the A / D conversion circuit in response to a data capture timing signal; and a low-pass filter that converts the video signal output from the low-pass filter into digital data. An arithmetic circuit for detecting the upper and lower mask portions by capturing one or more fields so as to be at a plurality of horizontal positions over one field in the vertical direction, and the incoming video signal based on a detection result of the arithmetic circuit. And an aspect conversion circuit for performing an aspect conversion of the image data. First means for detecting a brightness level of a mask portion, and second means for comparing the digital data with a predetermined reference value based on the brightness level of the upper and lower mask portions detected by the first means. A screen size adjusting device configured to obtain an upper image start line position and a lower image end line position based on a comparison result by the second means. 5. A screen size adjusting device for determining the presence or absence and position of upper and lower mask portions 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 digital signal output from the A / D conversion circuit in response to a data capture timing signal; and a low-pass filter that converts the video signal output from the low-pass filter into digital data. An arithmetic circuit for detecting the upper and lower mask portions by capturing one or more fields so as to be at a plurality of horizontal positions over one field in the vertical direction, and the incoming video signal based on a detection result of the arithmetic circuit. And an aspect conversion circuit for performing an aspect conversion of the image data. First means for detecting a luminance level of a mask portion; and a first value for comparing the digital data with a first value based on a predetermined reference value based on the luminance level of the upper and lower mask portions detected by the first means. 2
And a second means for performing binarization conversion to the values of the upper image start line position and the lower image end line position 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 having a level smaller than the reference value to 0 or a minimum value, and converts data having a level larger than the reference value to a maximum value. 6. The screen size adjusting device according to claim 5, wherein the screen size is adjusted. 7. The screen size adjusting device according to claim 1, wherein said data fetch 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 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 data of the incoming video signal for one or more fields so as to be at a plurality of horizontal positions over one field in a predetermined horizontal position in a predetermined horizontal position; A second step of checking the brightness level of the data at the upper and lower ends of the screen to determine whether or not to have upper and lower mask portions; A third step of detecting a luminance level; and performing a non-linear transformation on all the acquired data with reference to a predetermined reference value based on the detected luminance level. And a fifth step of obtaining an upper video start line position and a lower video end line position based on the non-linearly converted data. 9. A sixth step of differentiating the nonlinearly converted data in the vertical direction between the fourth step and the fifth step, and further squaring or converting the differentiated data to an absolute value. 9. The method according to claim 8, further comprising the steps of: 10. The method according to claim 1, wherein 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 any one of 8 and 9. 11. An aspect for detecting whether 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 data of the incoming video signal for one or more fields so as to be at a plurality of horizontal positions over one field in a predetermined horizontal position in a predetermined horizontal position; A second step of checking the brightness level of the data at the upper and lower ends of the screen to determine whether or not to have upper and lower mask portions; A third step of detecting a luminance level; and a fourth step of comparing a predetermined reference value based on the detected luminance level with all the acquired data. And a fifth step of obtaining an upper image start line position and a lower image end line position based on a result of the comparison in 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 video start line position and a lower video end line position if the video signal has upper and lower mask portions. A first step of capturing data of the incoming video signal for one or more fields so as to be at a plurality of horizontal positions over one field in a predetermined horizontal position in a predetermined horizontal position; A second step of checking the brightness level of the data at the upper and lower ends of the screen to determine whether or not to have upper and lower mask portions; A third step of detecting a luminance level, and all the acquired data are referred to as a first reference value based on a predetermined reference value based on the detected luminance level. Value and second
And a fifth step of calculating an upper image start line position and a lower image end line position based on the binarized data. Aspect detection method. 13. The fourth step comprises: comparing the digital data with the reference value, converting data having a level lower than the reference value to 0 or a minimum value, and converting data having a level larger than the reference value to a maximum value. 13. The aspect detection method according to claim 12, wherein the aspect conversion is performed. 14. The method according to claim 1, wherein the second and third steps divide the upper and lower ends of the screen into a plurality of blocks, and confirm a luminance level or detect a luminance level in each block. Claims 8 to 1
3. The aspect detection method according to any one of 3.