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US 7,623,576 B1Granted
Method and apparatus for interlaced/non-interlaced frame determination, repeat-field identification and scene-change detection
AssigneeSTMicroelectronics Asia Pacific Pte Ltd
InventorsYau Wei Lucas Hui, Kwong Huang Goh
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Abstract
A method of processing video data to detect field characteristics of the data, said data having a plurality of fields, including the steps of: comparing first and second fields, said first field being a successive field of said second field; comparing pixel values of respective sub-blocks of said first field and a third field, said second field being a successive field of said third field; determining whether said first field is an interlaced field or a progressive field with respect to a successive field of said first field based on said steps of comparing.
Claims20
A method of processing video data to detect field characteristics of the data, said data having a plurality of fields, comprising:
- in a video processing apparatus,
- calculating a first difference value as a difference between pixels of a first field and pixels of a second field, said first field being successive to said second field;
- calculating a second difference value between the pixels of said first field and pixels of a third field, said third field being successive to said first field;
- calculating a ratio between said first and second difference values;
- comparing said ratio with a threshold;
- determining whether said first field is an interlaced field or a progressive field with respect to said third field based on said steps of calculating, wherein the determining step includes determining whether said first field is an interlaced field or a progressive field based on said comparing step;
- and
- calculating the number of moving pixels between said second and third fields, wherein the determining step includes determining that said first field is an interlaced field if said number is lower than a moving pixel threshold, and determining that said first and third fields are progressive if said number is not lower than the moving pixel threshold.
5 more elements
An apparatus for processing video data to detect field characteristics of the data, said data having a plurality of fields, comprising:
- difference value calculating means for calculating a first difference value as a difference between pixels of a first field and pixels of a second field, said first field being a successive field of said second field, and calculating a second difference value between the pixels of said first field and pixels of a third field, said third field being a successive field of said first field;
- progressive/interlace decision means for determining whether said first field is an interlaced field or a progressive field with respect to said third field based on the first and second difference values, wherein the difference value calculating means includes subtractor means for calculating absolute pixel differences and accumulator means for accumulating the absolute pixel differences, wherein said subtractor means comprises:
- a first subtractor receiving a pixel of said first field and a first pixel of said second field and calculating a first pixel difference;
- a second subtractor receiving said pixel of said first field and a second pixel of said second field and calculating a second pixel difference;
- and
- a comparator selecting a smaller pixel difference between said first and second pixel differences, wherein the accumulator means accumulates said smaller pixel difference.
3 more elements
An apparatus for processing video data to detect field characteristics of the data, said data having a plurality of fields, comprising:
- difference value calculating means for calculating a first difference value as a difference between pixels of a first field and pixels of a second field, said first field being a successive field of said second field, and calculating a second difference value between the pixels of said first field and pixels of a third field, said third field being a successive field of said first field;
- progressive/interlace decision means for determining whether said first field is an interlaced field or a progressive field with respect to said third field based on the first and second difference values;
- input means;
- a first field memory having an input connected to said input means and an output connected to said difference value calculating means, said difference value calculating means being also connected to said input means;
- a second field memory connected to the output of said first field memory and having an output;
- and
- a moving pixel counter having inputs connected to said input means and the output of said second field memory, and an output connected to said interlaced/progressive decision unit, said moving pixel counter counting moving pixels between said second and third fields and to obtain a count value of the moving pixels, wherein said progressive/interlace decision means includes means for comparing said count value of moving pixels with a moving pixel threshold, and means for defining said first and third fields as progressive if said count value of moving pixels is lower than said moving pixel threshold, and for defining said first and third fields as interlaced if said count value of moving pixels is not lower than said moving pixel threshold.
4 more elements
A method of processing video data to detect field characteristics of the data, said data having a plurality of fields, comprising:
- in a video processing apparatus,
- calculating a first difference value as a difference between pixels of a first field and pixels of a second field, said first field being successive to said second field;
- calculating a second difference value between the pixels of said first field and pixels of a third field, said third field being successive to said first field;
- and
- determining whether said first field is an interlaced field or a progressive field with respect to said third field based on said steps of calculating, wherein said step of calculating a first difference value comprises for each of a plurality of the pixels of said first field:
- calculating pixel differences between the pixel of said first field and two pixels of said second field;
- selecting a smaller pixel difference between said pixel differences;
- and
- accumulating said smaller pixel difference.
6 more elements
A method of processing video data to detect field characteristics of the data, said data having a plurality of fields, comprising:
- in a video processing apparatus,
- calculating a first difference value as a difference between pixels of a first field and pixels of a second field, said first field being successive to said second field;
- calculating a second difference value between the pixels of said first field and pixels of a third field, said third field being successive to said first field;
- determining whether said first field is an interlaced field or a progressive field with respect to said third field based on said steps of calculating;
- and
- verifying whether a scene-change has occurred before performing said calculating steps, wherein if said step of verifying reveals that a scene-change has occurred, then the method includes performing a moving pixel detection by:
- calculating a first difference between a first pixel in said first field and a second pixel in said third field;
- calculating a second difference between a third pixel in said first field and said second pixel in said third field;
- calculating a third difference between said third pixel in said first field and a fourth pixel in said third field;
- determining said third and fourth pixels as interlaced if said first, second, and third differences are greater than an interlace threshold;
- and
- for each of a plurality of sub-blocks of said first and third fields, detecting a moving region by repeating said moving pixel detection for pixels of the sub-block;
- if the number of interlaced pixels in said sub-block is higher than a region threshold said sub-block is considered interlaced;
- and, if more than one sub-block is found interlaced, then said first and third fields are considered interlaced.
11 more elements
A method of processing video data to detect field characteristics of the data, the data having first, second, and third fields in which the third field is successive to the first field which is successive to the second field, the method comprising:
- in a video processing apparatus,
- determining, for each of a plurality of pixels of the third field, whether the pixel is a moving pixel by:
- calculating a difference between a value of the pixel and a value of a pixel in the second field having a position that is the same as a position of the pixel of the third field;
- and
- determining whether the calculated difference is greater than a moving threshold;
- calculating a moving pixel count value that indicates how many pixels of the third field are determining to be moving pixels;
- determining whether the pixel count value is less than a moving pixel count threshold;
- and
- determining whether the first field is an interlaced field or a progressive field with respect to the third field based on whether the pixel count value is less than the moving pixel count threshold.
6 more elements
Dependencies are inferred from the claim text.