METHOD AND RELATED CIRCUIT FOR DETECTING BLACK FRAMES IN VIDEO SIGNAL
First Claim
1. A method for detecting a black frame of a video signal comprising:
- receiving a frame data from the video signal;
the frame data comprising a plurality of pixel data each corresponding to a pixel of an image;
processing a setting step for setting a pattern comprising a plurality of reference positions;
processing a sampling step for determining reference pixels according to positions of the pixels in the image;
a pixel of the image is determined as a reference pixel if the position of the pixel equals a reference position;
the pattern limiting the number of reference pixels to be smaller than the number of pixels of the image, and keeping the number of reference pixels from changing as the pixel data corresponding to the pixels of the image change; and
processing a decision step for determining whether the pixel data corresponding to the pixels of the image fit a default according to the pixel data corresponding to the reference pixels.
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Abstract
A method and related circuit for detecting black frames, which are inserted between normal programs and commercial spots in a broadcasting video signal. For a frame in the video signal, representative pixels are selected as reference pixels according to their positions in the frame, and whether the frame is black can be determined efficiently according to statistical properties of these reference pixels. For example, pixels aligned in a diagonal of a frame can be selected as reference pixels to determine if the frame is black. Also, the invention applies to frequency domain video signals. Blocks are selected as reference blocks according to their position in a frame, and whether the frame is black is determined according to low-frequency components of reference blocks.
28 Citations
35 Claims
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1. A method for detecting a black frame of a video signal comprising:
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receiving a frame data from the video signal;
the frame data comprising a plurality of pixel data each corresponding to a pixel of an image;
processing a setting step for setting a pattern comprising a plurality of reference positions;
processing a sampling step for determining reference pixels according to positions of the pixels in the image;
a pixel of the image is determined as a reference pixel if the position of the pixel equals a reference position;
the pattern limiting the number of reference pixels to be smaller than the number of pixels of the image, and keeping the number of reference pixels from changing as the pixel data corresponding to the pixels of the image change; and
processing a decision step for determining whether the pixel data corresponding to the pixels of the image fit a default according to the pixel data corresponding to the reference pixels. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for detecting a black frame of a video signal, the video signal comprising a plurality of frame data in the frequency domain, the method comprising:
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receiving the frame data in the frequency domain from the video signal;
the frame data in the frequency domain corresponding to an image, the image comprising a plurality of blocks each comprising a plurality of pixels comprising corresponding pixel data;
wherein the frame data in the frequency domain comprises a plurality of low-frequency data each corresponding to a block of the image;
processing a setting step for setting a pattern comprising a plurality of reference positions;
processing a sampling step for determining reference blocks according to positions of the blocks in the image;
a block of the image is determined as a reference block if the position of the block equals a reference position;
the pattern limiting the number of reference blocks to be smaller than the number of pixels of the image; and
processing a decision step for determining whether the pixel data corresponding to the pixels of the image fit a default according to the low-frequency data corresponding to the reference blocks. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. A processing circuit for detecting a black frame of a video signal, the video signal comprising a plurality of frame data, the processing circuit comprising:
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a receiver for receiving a frame data from the video signal;
the frame data comprising a plurality of pixel data each corresponding to a pixel of an image;
a setting module for setting a pattern, the pattern comprising a plurality of reference positions;
a sampling module for determining reference pixels according to positions of the pixels in the image;
a pixel of the image is determined as a reference pixel if the position of the pixel equals a reference position;
the pattern limiting the number of reference pixels to be smaller than the number of pixels of the image, keeping the number of reference pixels from changing as the pixel data corresponding to the pixels of the image change; and
a decision module for determining whether the pixel data corresponding to the pixels of the image fit a default according to the pixel data corresponding to the reference pixels. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A processing circuit for detecting a black frame of a video signal, the video signal comprising a plurality of frame data in the frequency domain, the processing circuit comprising:
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a receiver for receiving a frame data in the frequency domain from the video signal;
the image comprising a plurality of blocks each comprising a plurality of pixels comprising corresponding pixel data;
wherein the frame data in the frequency domain comprises a plurality of low-frequency data each corresponding to a block of the image;
a setting module for setting a pattern, the pattern comprising a plurality of reference positions;
a sampling module for determining reference blocks according to positions of the blocks in the image;
a block of the image is determined as a reference block if the position of the block equals a reference position;
the pattern limiting the number of reference blocks to be smaller than the number of pixels of the image; and
a decision module for determining whether the pixel data corresponding to the pixels of the image fit a default according to the low-frequency data corresponding to the reference blocks. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35)
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Specification