Method and apparatus for extracting chrominance shape information for interlaced scan type image
View Patent ↗A method and apparatus for extracting chrominance shape information for an interlaced scan type image, which are used in a video compression coding/decoding system or a video manipulation equipment/system. According to the present invention, in an interlaced scan type image with arbitrary luminance shape information, chrominance shape information is extracted on the basis of four adjacent luminance shape pixels in two lines of the same type field. The present method and apparatus can solve a color bleeding problem in a conventional chrominance shape information extraction method considering no characteristic of the interlaced scan type image. Therefore, the present invention has the effect of significantly improving subjective picture quality.
1. A method for extracting chrominance shape pixels from luminance shape pixels for an interlaced video having two fields, comprising the steps of:
a) setting every four adjacent luminance shape pixels in two consecutive scan lines within a first field of the interlaced video to a first sub-sampling unit of a video coder; and
b) extracting an associated chrominance shape pixel on the basis of said four adjacent luminance shape pixels in the first sub-sampling unit.
2. The method as set forth in claim 1 , further comprising the step of extracting said associated chrominance shape pixel corresponding to a background, if none of said four adjacent luminance shape pixels in each of said sub-sampling units is an object pixel.
3. A method for extracting chrominance shape pixels from luminance shape pixels for an interlaced video having two fields, comprising the steps of:
a) setting every four adjacent luminance shape pixels in two consecutive scan lines within a first field of the interlaced video to a first sub-sampling unit of a video coder; and
b) extracting an associated chrominance shape pixel on the basis of said four adjacent luminance shape pixels if at least one of said four luminance shape pixels in the first sub-sampling unit is an object pixel.
4. The method as set forth in claim 3 , further comprising the step of extracting said associated chrominance shape pixel corresponding to a background, if none of said four adjacent luminance shape pixels in said sub-sampling units is an object pixel.
5. The method as set forth in claim 3 , wherein said two fields are top and bottom fields; and wherein said step (b) includes:
the step of, if said associated chrominance shape pixel to be extracted is present in said top field, extracting said associated chrominance shape pixel on the basis of four adjacent luminance shape pixels in said top field.
6. The method as set forth in claim 3 , wherein said two fields are top and bottom fields and wherein said step (b) includes:
the step of, if said associated chrominance pixel to be extracted is present in said bottom field, extracting said associated chrominance shape pixel on the basis of four adjacent luminance shape pixels in said bottom field.
7. The method as set forth in claim 3 , wherein said two fields are top and bottom fields.
8. The method as set forth in claim 3 , wherein
said two fields are top and bottom fields; and wherein said step (b) includes:
the step of, if said associated chrominance shape pixel to be extracted is present in said top field, extracting said associated chrominance shape pixel on the basis of four adjacent luminance shape pixels in said top field; and
wherein said step (b) includes:
the step of, if said associated chrominance shape pixel to be extracted is present in said bottom field, extracting said associated chrominance shape pixel on the basis of four adjacent luminance shape pixels in said bottom field.
9. An apparatus for extracting chrominance shape from luminance shape for an interlaced video, comprising:
a field separator for separating a frame based luminance shape into a top field luminance shape and a bottom field luminance shape;
top field sub-samplers for extracting first chrominance shape from said top field luminance shape on the basis of four adjacent luminance shape pixels in two consecutive lines of said top field;
bottom field sub-samplers for extracting second chrominance shape from said bottom field luminance shape on the basis of four adjacent luminance shape pixels in two consecutive lines of said bottom field; and
frame reconstruction means for reconstructing the chrominance shape by interleaving said first chrominance shape with said second chrominance shape line by line.
10. The apparatus as set forth in claim 9 , wherein
said top field sub-samplers set every four adjacent luminance shape pixels in two consecutive lines of said top field as a sub-sampling unit and extract an associated chrominance shape pixel corresponding to an object, if at least one of said four luminance shape pixels in each of said sub-sampling units is an object pixel; and
said bottom field sub-samplers set every four adjacent luminance shape pixels in two consecutive lines of said bottom field as a sub-sampling unit and extract an associated chrominance shape pixel corresponding to an object, if at least one of said four luminance shape pixels in each of said sub-sampling units is an object pixel.
11. The apparatus as set forth in claim 9 , wherein
said top field sub-samplers set every four adjacent luminance shape pixels in two consecutive lines of said top field as a sub-sampling unit and extract an associated chrominance shape pixel corresponding to a background, if none of said four luminance shape pixels in each of said sub-sampling units is an object pixel.
12. The apparatus as set forth in claim 9 , wherein
said bottom field sub-samplers set every four adjacent luminance shape pixels in two consecutive lines of said bottom field as a sub-sampling unit and extract an associated chrominance shape pixel corresponding to a background, if none of said four luminance shape pixels in each of said sub-sampling units is an object pixel.