JP4580347B2 - Flicker video conversion device, program and method thereof, and video display device - Google Patents

Description

  The present invention relates to a flicker video conversion device that converts video into a video that prevents light-sensitive seizures, a program and method thereof, and a video display device.

  In recent years, guidelines have been established for viewers who have watched TV programs to produce videos that do not cause light-sensitive seizures, starting with problems such as convulsions and feeling sick. Detection devices have been developed that detect images that can cause photosensitive seizures.

  For example, the 2001 ITC Guidelines (“ITC Guidance Note for Licensees on Flashing Image and Regular Patterns in Television”, 1994, 1998, 2001-2002) established by the Independent Television Commission (ITC) in the UK As a standard, an apparatus (Harding FPA: The Harding Flash and Pattern Analyzer; hereinafter referred to as a harding machine) that detects a video that may cause a photosensitive seizure has been developed (see Non-Patent Document 1).

  In addition, for example, a device that detects video that may cause light-sensitive seizures based on guidelines established by the Japan Broadcasting Corporation and the Japan Private Broadcasting Corporation (“Guidelines on video techniques such as animation”, 1998). (Reference measuring instrument) has been developed (see Non-Patent Document 2).

  In each of the above guidelines, flashing of luminance exceeding 3 times per second (6 times as the number of luminance changes; 3 Hz) or flashing red (red flicker) causes photosensitive seizures. The possibility is high. Therefore, the harding machine and the reference measuring device detect luminance flicker and red flicker exceeding 3 times per second while performing motion compensation in the video.

On the other hand, an apparatus that detects an image that is highly likely to cause a photosensitive attack and converts it into an image that prevents the photosensitive attack has been developed (see, for example, Non-Patent Document 3).
In the video filter device (video hazard blocker) disclosed in this Non-Patent Document 3, the risk level of the input video signal is calculated based on the time response of the visual system cell model, and when the risk level is high, Flicker components are suppressed by applying temporal low-pass filter processing to the video signal.
“Harding FPA website”, [online], [searched on January 11, 2006], Internet <http://www.hardingfpa.co.uk> Emoto, Otsuka, Yamaga, Uehara, Iguchi, Ito, Fujii, “Development of“ Reference Instrument ”for Guidelines for Animation Programs”, IEICE Technical Report, 22, No. 40, pp. 1-6 (1998) Kamijo, Takagi, Yamazaki, “Adaptive Dangerous Image Mitigation Filter“ Video Hazard Blocker ””, NEC Technical Report, vol.53, No.9, pp.47-50 (2000)

However, since the conventional device (video hazard blocker) performs low-pass filter processing when converting the video, there is a problem that the converted video is blurred, and the video is hard to see for the viewer.
Further, the video hazard blocker has a plurality of sets of coefficients for determining the strength of the low-pass filter, and the selection criteria for these coefficients are not specified. For this reason, the video converted by the video hazard blocker is not guaranteed to be in accordance with the above-mentioned guidelines, and cannot necessarily be said to be a video that prevents light-sensitive seizures.
In addition, the video hazard blocker only supports NTSC (National TV Standards Committee) signals as video signals, and therefore cannot handle various types of video (video files) processed and viewed on a computer. There is a problem.

  The present invention has been made in view of the above problems, and the occurrence of luminance flicker and red flicker in various images that can be processed in units of frames is defined by a predetermined reference value (for example, guidelines). And a flicker video conversion device capable of converting the signal so as not to exceed 3 Hz) and converting the video so as not to cause blurring, a program and method thereof, and a video display device. Objective.

  The present invention was devised to achieve the above object, and first, the flicker video conversion device according to claim 1 has a frequency higher than an inappropriate reference frequency predetermined as a visually inappropriate luminance change. A flicker video conversion device that converts a video in the video section into a video in which the frequency of the flicker is equal to or lower than the inappropriate reference frequency based on information indicating a video section in which a large flicker occurs. And an intra-block frame replacement unit.

  In such a configuration, when the frame frequency is set to N hertz and the improper reference frequency is set to M hertz, the flicker video converting apparatus converts consecutive frames in the video section to N / (2 × M) or more by the video section dividing unit. Divide into blocks consisting of several frames. For example, when the frame frequency is 30 hertz (Hz) and the inappropriate reference frequency is 3 Hz (frequency at which flicker occurs exceeding 3 times per second (6 times the number of luminance changes)), the number is 5 frames or more. Divide every frame. At least in this block, if the occurrence of a visually inappropriate luminance change is suppressed, the occurrence of flicker exceeding an inappropriate reference frequency in the entire visually inappropriate video section can be suppressed.

  Then, the flicker video conversion apparatus converts, for each block divided by the video section dividing unit by the intra-frame frame replacing unit, all frame images included in the block into one frame image included in the block. Replace. As a result, the images of all the frames included in the block become the same image, and at least in this block, a visually inappropriate luminance change does not occur.

  Further, the flicker video conversion apparatus according to claim 2 is the flicker video conversion apparatus according to claim 1, wherein the intra-block frame replacement means includes a head block replacement means, a dissimilar frame selection means, and a subsequent block replacement. Means.

  In such a configuration, the flicker video conversion device converts all the frame images included in the first block divided by the video section dividing unit by the first block replacement unit into one frame image included in the first block. By replacing, all the frames in the first block are made the same image.

Then, the flicker video conversion device uses the dissimilar frame selection unit to select a frame image included in the previous block and all the images included in the subsequent block in the subsequent block that has been replaced with the previous block. A frame having the lowest degree of similarity with the frame image is selected. As the degree of similarity, a distance in the color space of each pixel between frames, a luminance difference, an edge feature amount, or the like can be used.
Then, the flicker video converting apparatus replaces all the frame images included in the subsequent block with the image of the frame selected by the dissimilar frame selecting unit by the subsequent block replacing unit.

Then, by using the dissimilar frame selection unit and the subsequent block replacement unit, the video sections in which the flickers of the inappropriate reference frequency are sequentially generated are made the same image in units of blocks.
At this time, since the image of the frame to be replaced in the block is the image of the frame having the lowest degree of similarity with the image of the frame included in the previous block, the difference in the image of the frame between the blocks is the largest, and the video Can be accurately expressed.

  According to a third aspect of the present invention, there is provided a video display device for displaying a video, comprising flicker video section detecting means and the flicker video conversion device according to the first or second aspect.

In such a configuration, the video display apparatus detects, from the input video, a video section in which flicker having a frequency larger than an inappropriate reference frequency predetermined as a visually inappropriate luminance change is detected by the flicker video section detection means. To do. Then, the video display device uses the flicker video conversion device to convert the video in the video section detected by the flicker video section detection means into a video in which the flicker frequency is equal to or lower than the inappropriate reference frequency.
As a result, it is possible to convert the video only in the video section where a visually inappropriate luminance change occurs.

  Furthermore, the flicker video conversion program according to claim 4 is based on information indicating a video section in which flicker having a frequency higher than a predetermined inappropriate reference frequency is generated as a visually inappropriate luminance change. In order to convert the video of the above into a video in which the flicker frequency is equal to or less than the inappropriate reference frequency, the computer is caused to function as a video section dividing unit, a leading block replacing unit, a dissimilar frame selecting unit, and a subsequent block replacing unit The configuration.

In such a configuration, the flicker video conversion program uses the video segment dividing means to convert consecutive frames in the video segment to N / (2 × M) or more when the frame frequency is N hertz and the inappropriate reference frequency is M hertz. Divide into blocks consisting of several frames.
Then, the flicker video conversion program replaces the images of all frames included in the head block divided by the video section dividing means with the images of one frame included in the head block by the head block replacing means. . As a result, all the frames in the block become the same image, and flicker does not occur at least in this block.

Then, the flicker video conversion program, by the dissimilar frame selection means, in the subsequent block that has been consecutively replaced with the previous block, the image of the frame included in the previous block and all the images included in the subsequent block A frame having the lowest degree of similarity with the frame image is selected.
Further, the flicker video conversion program replaces the images of all the frames included in the subsequent block with the image of the frame selected by the dissimilar frame selecting unit by the subsequent block replacing unit.
As a result, the occurrence of flicker with an inappropriate reference frequency is suppressed in the entire visually inappropriate video section.

  Further, the flicker video conversion method according to claim 5 is based on information indicating a video section in which flicker having a frequency larger than a predetermined inappropriate reference frequency is generated as a visually inappropriate luminance change. Is a flicker video converting method for converting the video of the video into a video in which the frequency of the flicker is equal to or lower than the inappropriate reference frequency, the video section dividing step, the leading block replacement step, the dissimilar frame selection step, and the subsequent block A replacement step.

In such a procedure, the flicker video conversion method is a video segment dividing step, wherein when the frame frequency is set to N hertz and the inappropriate reference frequency is set to M hertz by the video segment dividing means, consecutive frames in the video segment are converted into N / Divided into blocks consisting of more than (2 × M) frames.
Then, in the flicker video conversion method, at the head block replacement step, the images of all frames included in the head block divided at the video section dividing step are converted into one image included in the head block by the head block replacement means. Replace with the frame image.

Then, in the flicker video conversion method, in the dissimilar frame selection step, the dissimilar frame selection means, in a block subsequent to the previous block that has already been replaced, the image of the frame included in the previous block, A frame having the lowest degree of similarity is selected from the images of all the frames included in the subsequent block.
Further, in the flicker video conversion method, in the subsequent block replacement step, the image of all frames included in the subsequent block is replaced with the image of the frame selected in the dissimilar frame selection step by the subsequent block replacement unit. .

The present invention has the following excellent effects.
According to the first or fifth aspect of the present invention, an image in a video section in which flicker having a frequency larger than a predetermined inappropriate reference frequency is generated as a visually inappropriate luminance change, and the flicker frequency is set. It is possible to convert to an image having an inappropriate reference frequency or lower. As a result, the video producer can save time and effort to edit the video even if the produced video has flicker exceeding the inappropriate reference frequency.

  Further, according to the present invention, by setting the inappropriate reference frequency to 3 Hz, it is possible to reliably suppress luminance flicker and red flicker of 3 Hz defined by the ITC guidelines. As a result, in an arbitrary video, a video in a video section where flicker exceeding an inappropriate reference frequency occurs can be converted into a video in which the occurrence of a light-sensitive seizure is prevented.

  According to the second aspect of the present invention, since a video section in which flicker exceeding an inappropriate reference frequency occurs is replaced with an image of a frame having the lowest degree of similarity for each block, And the difference in the video for each block becomes clear and the motion of the video can be expressed accurately.

  According to the third aspect of the present invention, a video section where flicker exceeding an inappropriate reference frequency is detected from an arbitrary video, and the flicker frequency is equal to or lower than the inappropriate reference frequency in the video section. Thus, the video can be converted. As a result, an arbitrary video can be converted into a video in which the occurrence of a photosensitive seizure is prevented.

  According to the invention described in claim 4, since the video is converted in units of frames and does not depend on the size, resolution, or frame frequency of the video, the occurrence of light-sensitive seizures in various types of video is prevented. Can be converted to video.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Configuration of video display device]
First, the configuration of the video display device will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a video display apparatus according to the present invention. The video display device 1 reproduces and displays a video signal while preventing display of a frame in which a visually inappropriate luminance change occurs. In this embodiment, the video display device 1 is configured so that the video signal does not generate frequency flicker (luminance flicker, red flicker) that may cause a light-sensitive seizure specified in the ITC guidelines. Is converted and displayed.
Here, as shown in FIG. 1, the video display device 1 includes an A / D conversion unit 2, a frame memory 3, a D / A conversion unit 4, an output unit 5, a flicker video detection unit 6, and a flicker. And a video conversion device 7.

  The A / D conversion means 2 converts the input video signal, which is an analog signal, into a digital signal and stores it in the frame memory 3 for each frame (frame image) which is a video display unit.

  The frame memory 3 stores video in units of frames and is a general storage unit such as a video memory. The frame memory 3 detects a time interval (inappropriate image interval) of a frame in which a visually inappropriate luminance change exists in a flicker image detection means 6 to be described later, and a flicker image conversion device 7 to be described later. , The flicker frequency is converted to an image having an inappropriate reference frequency or lower, and therefore functions as a buffer for accumulating a plurality of frames.

  The D / A conversion means 4 sequentially reads out the frames stored in the frame memory 3, converts them into analog signals, and outputs them as output signals to the output means 5. Note that, when a plurality of frames are stored in the frame memory 3, the D / A conversion means 4 reads the frames in time series by sequentially changing the reading position.

  The output means 5 is a general display device such as a liquid crystal display, a plasma display, a projector, or a CRT. Here, the output unit 5 is provided in the video display device 1, but the output signal output from the D / A conversion unit 4 is separated from the output signal output from the D / A conversion unit 4. It is good also as outputting to an output means.

  The flicker image detection means 6 detects a visually inappropriate luminance change from the image. Here, the flicker image detection means 6 sequentially reads out the frames stored in the frame memory 3 and starts and ends the frames that have generated a visually inappropriate luminance change based on the luminance change between the frames. Are output as inappropriate video section information. The inappropriate video section information is information for specifying a start frame and an end frame, and is, for example, a frame number or a frame address stored in the frame memory 3.

  As the flicker image detecting means 6, for example, a conventional harding machine or a reference measuring instrument can be used. Here, the flicker image detecting means 6 detects flicker exceeding 3 times per second (3 Hz), which is the visually inappropriate flicker reference frequency (inappropriate reference frequency) defined in the ITC guidelines. And output as inappropriate video section information.

The flicker video conversion device 7 displays an image in a video section (inappropriate video section) in which flicker having a frequency larger than a predetermined inappropriate reference frequency as a visually inappropriate luminance change, and flicker frequency is inappropriate. The video is converted to an image having a reference frequency or lower.
Here, the flicker video conversion device 7 converts the video in the inappropriate video section to a video in which flicker exceeding 3 Hz does not occur based on the inappropriate video section information output from the flicker video detection means 6.
Note that the configuration of the flicker video conversion device 7 will be described in more detail with reference to FIG.

(Detailed configuration of flicker video converter)
FIG. 2 is a block diagram showing the configuration of the flicker video conversion apparatus according to the present invention. Here, the flicker video converting apparatus 7 includes a video section dividing unit 70 and an intra-block frame replacing unit 71.
For example, in order to prevent flicker exceeding 3 Hz as an inappropriate reference frequency in an image, when the frame frequency is N hertz (Hz), the image is visually inappropriate in N / 6 or more frames. It is sufficient that no change in luminance occurs. Hereinafter, this is realized by the video section dividing means 70 and the intra-block frame replacing means 71.

  The video segment dividing means 70, when the inappropriate reference frequency is M hertz (Hz) and the frame frequency is N hertz (Hz), the continuous frame group in the inappropriate video segment is N / (2 × M) or more. It is divided into blocks each consisting of a number of frames (the number of frames in a block). For example, when the video signal is an NTSC signal having a frame frequency of 30 Hz, the video section dividing unit 70 divides the frame group into blocks each including five (30 [Hz] / 6) frames. The number of frames to be divided may be stored in advance in a storage unit (not shown) or may be set from the outside.

Here, with reference to FIG. 3 (refer to FIG. 2 as appropriate), a method in which the video segment dividing means 70 divides a continuous frame group in the inappropriate video segment will be described. FIG. 3 is an explanatory diagram for explaining a method of dividing an inappropriate video section in the video section dividing means. Here, the case where the video signal is an NTSC signal with a frame frequency of 30 Hz will be described as an example.
As shown in FIG. 3, the video signal is composed of the first frame to the 62nd frame. From the flicker video detection means 6, the start frame of the inappropriate video section is the second frame and the end frame is the 59th frame. It shall be notified.

At this time, the video segment dividing means 70 divides the frame of the inappropriate video segment into blocks each composed of five frames. Here, the video segment dividing means 70 divides the inappropriate video segment into the first block composed of the second to sixth frames, the second block composed of the seventh to eleventh frames, and the third block composed of the twelfth to sixteenth frames. The block is divided into twelfth blocks consisting of 57th to 61st frames. Since the inappropriate video section is not necessarily divisible by a number equal to or greater than N / 6, the last block (here, the twelfth block) includes a frame that exceeds the end frame of the inappropriate video section. Of course, the last block may be the end frame.
Returning to FIG. 2, the description of the configuration of the flicker video converting apparatus 7 will be continued.

  The intra-frame frame replacing means 71 is an image of all frames included in the block for each block divided by the video section dividing means 70 in a time-series continuous frame group stored in the frame memory 3. Replacement is performed with an image of one frame included in the block. Here, the intra-frame frame replacing unit 71 includes a leading block replacing unit 71a, a dissimilar frame selecting unit 71b, and a subsequent block replacing unit 71c.

  The first block replacing unit 71a includes all the images of the frames included in the first block (first block in FIG. 3) in the inappropriate video section divided by the video section dividing unit 70 in the first block. It replaces with an image of one frame. Here, the head block replacing means 71a replaces the image of the other frame with the image of the start frame of the inappropriate video section, with the head block as the processing target block. Note that this replacement source frame does not need to be a start frame, and any frame may be used as long as it is a frame in the first block.

Further, after completion of the replacement, the head block replacement unit 71a outputs a replacement completion notification indicating that to the dissimilar frame selection unit 71b. The replacement completion notification includes information indicating the original frame (replacement frame) in which replacement has been performed and information indicating the first frame of the subsequent block following the processing target block. The information indicating the replacement frame or the head frame is information for specifying the frame, and is, for example, a frame number, an address of a frame stored in the frame memory 3, or the like.
By notifying the first frame of the subsequent block, the processing target block is changed from the current processing target block to the subsequent block in the dissimilar frame selection means 71b described later.

The dissimilar frame selection means 71b is similar to the image of the frame included in the previous block and the image of all the frames included in the subsequent block in the subsequent block succeeding the previous block that has already been replaced. The frame with the lowest degree (the most dissimilar) is selected. Information indicating the frame selected by the dissimilar frame selecting means 71b (dissimilar frame information) is output to the subsequent block replacing means 71c. The dissimilar frame information is information for specifying the frame, and is, for example, a frame number, a frame address stored in the frame memory 3, or the like.
Further, the dissimilar frame selection unit 71b changes the processing target block to a subsequent block when the head block replacement unit 71a or the subsequent block replacement unit 71c is notified of the replacement completion of the processing target block.

  Note that the dissimilar frame selection unit 71b includes a similarity calculation unit 711b that calculates a similarity indicating the degree of similarity between the images of two frames.

  As shown in the following equation (1), the similarity calculation unit 711b uses a value obtained by summing up the differences (distances) of colors (RGB values) in the color space between the frames to be compared as the similarity. calculate. In the similarity of the equation (1), the smaller the value, the more similar the two frame images, and the larger the value, the determination criterion is that the two frame images are not similar.

  Here, xmax and ymax indicate the number of horizontal pixels and the number of vertical pixels of the frame, respectively. In addition, Ra (x, y), Ga (x, y), and Ba (x, y) are RGB values in the pixel (x, y) of the first frame to be compared, Rb (x, y), Gb (x, y) and Bb (x, y) respectively indicate RGB values in the pixel (x, y) of the second frame to be compared.

The method for calculating the degree of similarity is not limited to the distance in the color space, and a general similarity calculation method can be used.
For example, the sum of the pixel brightness differences (luminance differences) between frames may be used as the similarity. In addition, for example, an image of a frame may be divided into a plurality of blocks, an edge feature amount indicating the direction of an edge in the block may be obtained, and the sum of differences in edge feature amounts for each block may be used as the similarity.
Then, the dissimilar frame selection unit 71b, based on the similarity calculated by the similarity calculation unit 711b, the image of the frame included in the previous block and all the frames included in the subsequent block (processing target block). The frame having the lowest degree of similarity with the image of is selected.

  Subsequent block replacement means 71c is the image of the frame selected by dissimilar frame selection means 71b in the second and subsequent blocks (after the second block in FIG. 3) in the inappropriate video section divided by video section dividing means 70. Thus, the images of all the frames included in the processing target block are replaced.

  Note that the image of the replaced frame is the image of the frame having the lowest degree of similarity to the image of the frame of the previous block, and therefore the difference in the image of the frame between the blocks is the largest. Therefore, even if the video converted in this way is a video with intense motion, the motion can be accurately expressed.

  Further, after the replacement is completed, the subsequent block replacement unit 71c outputs a replacement completion notification indicating that to the dissimilar frame selection unit 71b. The replacement completion notification includes information indicating the original frame (replacement frame) in which replacement has been performed and information indicating the first frame of the subsequent block following the processing target block. The information indicating the replacement frame or the head frame is information for specifying the frame, and is, for example, a frame number, an address of a frame stored in the frame memory 3, or the like.

  Here, referring to FIG. 4 (refer to FIG. 2 as appropriate), each block divided by the video section dividing means 70 in the frame group stored in the frame memory 3 in time series by the intra-frame frame replacing means 71 Next, a method for replacing the images of all the frames included in the block with the images of one frame included in the block will be described. FIG. 4 is an explanatory diagram for explaining a technique for replacing a frame in a block. Here, the case where the video signal is an NTSC signal having a frame frequency of 30 Hz is taken as an example, and as described with reference to FIG. 3, the video segment dividing unit 70 blocks the inappropriate video segment from five frames. It is assumed that each is divided. In FIG. 4, the left frame group indicates a video before conversion, and the right frame group indicates a video after conversion.

As shown in FIG. 4, the intra-block frame replacing means 71 replaces the images of the third to sixth frames with the image of the second frame (starting frame of the inappropriate video section) that is the first frame of the first block. .
Then, the intra-frame frame replacing means 71 is the most similar between the second frame replaced by the first block and all the frames (seventh to eleventh frames) in the subsequent second block. The image of the other frame is replaced with the image of the frame with a low degree. Here, the frame with the lowest degree of similarity is the ninth frame, and the images of the seventh, eighth, tenth and eleventh frames are replaced with the image of the ninth frame.

Further, the intra-frame frame replacing means 71 is the most similar between the ninth frame replaced with the second block and all the frames (12th to 16th frames) of the third block in the subsequent third block. The image of the other frame is replaced with the image of the frame having a low degree of. Here, the frame with the lowest degree of similarity is the 13th frame, and the images of the 12th and 14th to 16th frames are replaced with the image of the 13th frame.
Then, the intra-block frame replacing means 71 sequentially replaces the frames of the subsequent blocks with the image of the frame having the lowest degree of similarity with the previously replaced frame.

  Finally, the intra-block frame replacing means 71 replaces the frame replaced with the eleventh block (not shown) in the twelfth block including the end frame of the inappropriate video section, and all the frames of the twelfth block (the 57th block). To the 61st frame), the image of the other frame is replaced with the image of the frame having the lowest degree of similarity. Here, the frame with the lowest degree of similarity is the 58th frame, and the images of the 57th and 59th to 61st frames are replaced with the image of the 58th frame.

As described above, when the frame frequency is N hertz (Hz), the flicker video conversion device 7 (FIG. 2) can display the same video in the inappropriate video section for every N / 6 or more frames. Convert to video composed of frames. As a result, the flicker video conversion device 7 can suppress luminance flicker and red flicker to 3 Hz or less, and can convert the video into a video in which light-sensitive seizure is prevented.
Further, the flicker video conversion device 7 replaces the image of the frame included in the subsequent block with the image of the frame having the lowest degree of similarity to the frame of the previous block, so that the video in the inappropriate video section is blurred. There is no.

Although the configuration of the flicker video conversion apparatus 7 (FIG. 2) has been described above, the flicker video conversion apparatus 7 can be operated by a flicker video conversion program that causes a general computer to function as each unit described above.
As a result, the flicker video conversion program converts a video that may cause a light-sensitive seizure into a video with a reduced possibility even in a video stored in a general video buffer such as a personal computer. Can do.

  For example, as shown in FIG. 5, a personal computer 1B having a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an external storage device, etc., not shown, is described with reference to FIG. By making the flicker video detection means 6 and the flicker video conversion device 7 into a flicker video detection program 6B and a flicker video conversion program 7B, respectively, a general video such as a video file stored in the video buffer 3B can be obtained. It can be converted into an image in which luminance flicker and red flicker are suppressed to 3 Hz or less.

  In this case, if the video file is compressed in the personal computer 1B, it is sequentially expanded and input to the video buffer 3B. Then, the flicker video detection program 6B detects a video section (inappropriate video section) in which luminance flicker or red flicker is 3 Hz or more from the frame stored in the video buffer 3B, and notifies the flicker video conversion program 7B. .

Thereafter, the flicker video conversion program 7B determines the frame so that the luminance flicker and the red flicker are 3 Hz or less in the inappropriate video section notified from the flicker video detection program 6B in the frame group stored in the video buffer 3B. Perform conversion.
The video file on the video buffer 3B thus converted can be converted into an arbitrary video format. In other words, since the present invention performs conversion processing in units of frames, it can handle various types of video (video files) without depending on the video encoding format.

[Operation of video display device (flicker video conversion device)]
Next, the operation of the video display device 1 will be described with reference to FIG. 6 (refer to FIGS. 1 and 2 for the configuration). Here, the operation of the flicker video conversion device 7 which is a characteristic part of the present invention in the video display device 1 will be described. FIG. 6 is a flowchart showing an operation of flicker video conversion according to the present invention.

  First, as an initial setting, the flicker video conversion device 7 sets the number of frames (number of frames in a block) when the inappropriate video section indicated by the inappropriate video section information notified from the flicker video detection means 6 is divided into blocks. Set (step S1). The number of frames in the block is N / (2 × M) or more when the frame frequency is N hertz (Hz) and the inappropriate reference frequency is M hertz (Hz).

(Video section division step)
The flicker video conversion device 7 receives the inappropriate video segment information (start frame, end frame) from the flicker video detection unit 6 by the video segment dividing unit 70 (step S2). The inappropriate video section is divided from the start frame for each number of frames in the block set in step S1 (step S3).

(First block replacement step)
Then, the flicker video conversion device 7 replaces all frame images in the head block with the frame image of the start frame by the head block replacing means 71a of the intra-block frame replacing means 71 (step S4).

(Dissimilar frame selection step)
Thereafter, the flicker video conversion device 7 changes the processing target block to the subsequent block by the dissimilar frame selection means 71b (step S5).
Then, the flicker video conversion device 7 calculates the similarity between all the frame images in the processing target block and the frame image of the previous block by the similarity calculation means 711b of the dissimilar frame selection means 71b (step S6). ).
Further, the flicker video conversion device 7 selects a frame having the lowest degree of similarity based on the similarity calculated in step S6 by the dissimilar frame selection means 71b (step S7).

(Subsequent block replacement step)
Then, the flicker video conversion device 7 replaces all frame images in the processing target block with the image of the frame having the lowest degree of similarity selected in step S7 (dissimilar frame image) by the subsequent block replacement unit 71c. (Step S8).
Here, the flicker video conversion apparatus 7 determines whether or not the processing target block includes the end frame notified in step S2 (step S9), and if the end frame is not included (in step S9). No), returning to step S5, the process target block is changed to the subsequent block, and the process is continued.

On the other hand, if the processing target block includes an end frame (Yes in step S9), the flicker video conversion device 7 further notifies other inappropriate video section information from the flicker video detection means 6. It is determined whether or not (step S10).
If other inappropriate video section information is notified (Yes in step S10), the flicker video conversion device 7 returns to step S2 and continues the process in the new inappropriate video section. On the other hand, when other inappropriate video section information is not notified (No in step S10), the flicker video conversion device 7 ends the operation.

  With the above operation, the flicker video conversion device 7 can suppress the luminance flicker and the red flicker below the inappropriate reference frequency in the inappropriate video section, and convert the video into a video in which the photosensitive seizure is prevented.

It is a block diagram which shows the structure of the video display apparatus which concerns on this invention. It is a block diagram which shows the structure of the flicker video conversion apparatus based on this invention. It is explanatory drawing for demonstrating the division | segmentation method of the improper video area in the video area division | segmentation means of the flicker video detection apparatus which concerns on this invention. It is explanatory drawing for demonstrating the method to replace the flame | frame in a block in the flame | frame replacement means in a block of the flicker video detection apparatus based on this invention. It is a conceptual diagram which shows the concept which operates the flicker video conversion program based on this invention on a personal computer. 6 is a flowchart showing an operation of flicker video conversion according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Video display apparatus 2 A / D conversion means 3 Frame memory 4 D / A conversion means 5 Output means 6 Flicker video detection means 7 Flicker video conversion apparatus 70 Video section division means 71 Intra-block frame replacement means 71a Leading block replacement means 71b Non Similar frame selecting means 711b Similarity calculating means 71c Subsequent block replacing means

Claims (5)

Based on information indicating a video section in which a flicker having a frequency higher than a predetermined inappropriate reference frequency is generated as a visually inappropriate luminance change, the video of the video section is converted to the inappropriate reference frequency. A flicker video conversion device for converting into the following video,
Video section dividing means for dividing a continuous frame in the video section into blocks each composed of N / (2 × M) or more frames, where the frame frequency is N hertz and the inappropriate reference frequency is M hertz. ,
For each block divided by the video section dividing means, an intra-block frame replacing means for replacing the images of all the frames included in the block with an image of one frame included in the block;
A flicker video conversion device comprising: The intra-frame frame replacement means includes:
First block replacement means for replacing the images of all frames included in the first block divided by the video section dividing means with images of one frame included in the first block;
In the subsequent block that is continuous with the previous block that has already been replaced, the degree of similarity is the lowest between the image of the frame included in the previous block and the image of all the frames included in the subsequent block. Dissimilar frame selection means for selecting a frame;
Subsequent block replacement means for replacing the images of all frames included in the subsequent block with the image of the frame selected by the dissimilar frame selection means;
The flicker video conversion apparatus according to claim 1, further comprising: In a video display device that displays video,
Flicker video section detecting means for detecting a video section in which flicker having a frequency larger than a predetermined inappropriate reference frequency as a visually inappropriate luminance change is detected from the input video;
The flicker video conversion device according to claim 1 or 2, wherein the video in the video section detected by the flicker video section detection means is converted into a video in which the frequency of the flicker is equal to or lower than the inappropriate reference frequency.
A video display device comprising: Based on information indicating a video section in which a flicker having a frequency higher than a predetermined inappropriate reference frequency is generated as a visually inappropriate luminance change, the video of the video section is converted to the inappropriate reference frequency. In order to convert to the following video,
Video section dividing means for dividing a continuous frame in the video section into blocks each composed of N / (2 × M) or more frames when the frame frequency is N hertz and the inappropriate reference frequency is M hertz.
First block replacement means for replacing all frame images included in the first block divided by the video section dividing means with one frame image included in the first block;
In the subsequent block that is continuous with the previous block that has already been replaced, the degree of similarity is the lowest between the image of the frame included in the previous block and the image of all the frames included in the subsequent block. Dissimilar frame selection means for selecting a frame,
Subsequent block replacement means for replacing the images of all frames included in the subsequent block with the image of the frame selected by the dissimilar frame selection means,
Flicker video conversion program characterized by causing it to function as Based on information indicating a video section in which a flicker having a frequency higher than a predetermined inappropriate reference frequency is generated as a visually inappropriate luminance change, the video of the video section is converted to the inappropriate reference frequency. A flicker video conversion method for converting to the following video,
When the frame frequency is set to N hertz and the inappropriate reference frequency is set to M hertz by the video segment dividing means, the continuous frames in the video segment are divided into blocks composed of N / (2 × M) or more frames. Video segment division step to be performed;
A leading block replacement step of replacing images of all frames included in the leading block divided in the video section dividing step with images of one frame included in the leading block by the leading block replacing means;
By the dissimilar frame selection means, in a subsequent block that is continuous with the previous block that has already been replaced, between the image of the frame included in the previous block and the image of all the frames included in the subsequent block A dissimilar frame selection step for selecting a frame having the lowest degree of similarity;
Subsequent block replacement step of replacing all frame images included in the subsequent block with the image of the frame selected in the dissimilar frame selection step by subsequent block replacement means;
A flicker video conversion method comprising:

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