摘要:
Methods and systems for data compression and decompression are disclosed. Specifically, the method for data compression of the present invention receives four inputs representing pixel information of an image and performs a combination of a 4-point discrete cosine transform (DCT) and a weighting function to obtain four outputs representing digital representations of an image. The method for data decompression receives four inputs representing digital representations of an image and performs a combination of an inverse weighting function and a 4-point inverse discrete cosine transform (IDCT) to obtain pixel components of an image. The methods and systems of the present invention may be used in optimizing digital video encoders and decoders.
摘要:
Methods and systems of the present invention obtain a motion vector between two frames of video image data. Specifically, methods and systems of the present invention may be used to estimate a motion vector for each macroblock of a current frame with respect to a reference frame in a multi-stage operation. In a first stage, an application implementing the process of the present invention coarsely searches a first search area of the reference frame to obtain a candidate supermacroblock that best approximates a supermacroblock in the current frame. In a second stage, the supermacroblock is divided into a plurality of macroblocks. Each of the macroblocks is used to construct search areas which are then searched to obtain a candidate macroblock that best appropriates a macroblock in the current frame. Additional stages may be used to further fine-tune the approximation to the macroblock. The methods and systems of the present invention may be used in optimizing digital video encoders, decoders, and video format converters.
摘要:
Digital video tape recorder which operates to receive an advanced television (ATV) signal to be recorded, provide a portion such as a low-band coefficient of an intra-coded frame of the ATV signal as variable-speed data, and record the digital video data and the variable-speed data in a main and a marginal area, respectively, of successive tracks on the record medium in which the marginal area is located on each track at a position which is reproducible in a fast-speed reproducing mode. The digital video tape recorder reproduces the recorded data in the fast-speed reproducing mode by reproducing the portion of the signal stored from the marginal area of each track which is located at specific reproducible areas.
摘要:
Methods and systems for obtaining a motion vector between two frames of video image data are disclosed. Specifically, methods and systems of the present invention may be used to perform a block-matching algorithm over a two-dimensional search area in a manner that reduces number of comparisons. In particular, the method determines a best candidate block for each strip based by searching in a first dimension of a two-dimensional search area and based on a predetermined difference criterion. The method then determines a second set of best candidate blocks by performing a limited search in the other direction based on the results from the search in the first dimension. The method then determines a motion vector for the best candidate block. Integral projection arrays may be used to further optimize the search. The methods and systems of the present invention may be used in optimizing digital video encoders, decoders, and format converters.
摘要:
Methods and systems for obtaining a motion vector between two frames of video image data are disclosed. Specifically, methods and systems of the present invention may be used to estimate a motion vector for each macroblock of a current frame with respect to a reference frame in a multi-stage operation. In a transcoder, motion estimation may be performed in the compressed domain eliminating the need to fully decode the compressed data in the first format before reencoding in a second format. In a first stage, an application implementing the process of the present invention obtains a motion vector between first and second pictures of video image data in a video sequence. Each picture includes a plurality of supermacroblocks, each having a plurality of macroblocks. For each supermacroblock of the first picture, a match supermacroblock in the second picture is determined that best matches the supermacroblock of the first picture. For each macroblock in the first picture supermacroblock, a macroblock in the second picture is determined that best matches the macroblock in the first picture supermacroblock. Macroblocks are determined by searching the second picture for a candidate macroblock that best matches the macroblock in the first picture supermacroblock. The search begins at a macroblock in the second picture supermacroblock that corresponds to the first macroblock in the first picture supermacroblock and a motion vector is determined based on the candidate macroblock. For the remaining macroblocks in the first picture supermacroblock, motion vectors are estimated based on the macroblocks in supermacroblocks of the second picture that neighbor the candidate macroblock.
摘要:
Methods and systems for obtaining a motion vector between two frames of video image data are disclosed. Specifically, methods and systems of the present invention may be used to estimate a motion vector for each macroblock of a current frame with respect to a reference frame in a multi-stage operation. In a transcoder, motion estimation may be performed in the compressed domain eliminating the need to fully decode the compressed data in the first format before reencoding in a second format. In a first stage, an application implementing the process of the present invention obtains a motion vector between first and second pictures of video image data in a video sequence. Each picture includes a plurality of supermacroblocks, each having a plurality of macroblocks. For each supermacroblock of the first picture, a match supermacroblock in the second picture is determined that best matches the supermacroblock of the first picture. For each macroblock in the first picture supermacroblock, a macroblock in the second picture is determined that best matches the macroblock in the first picture supermacroblock. Macroblocks are determined by searching the second picture for a candidate macroblock that best matches the macroblock in the first picture supermacroblock. The search begins at a macroblock in the second picture supermacroblock that corresponds to the first macroblock in the first picture supermacroblock and a motion vector is determined based on the candidate macroblock. For the remaining macroblocks in the first picture supermacroblock, motion vectors are estimated based on the macroblocks in supermacroblocks of the second picture that neighbor the candidate macroblock.
摘要:
Methods and systems for data compression and decompression are disclosed. Specifically, the method for data compression of the present invention receives eight inputs representing pixel information of an image and performs a combination of an 8-point discrete cosine transform (DCT) and weighting function to obtain eight outputs representing digital representations of an image. The method for data decompression receives eight inputs representing digital representations of an image and performs a combination of an inverse weighting function and an 8-point inverse discrete cosine transform (IDCT) to obtain pixel components of an image. The methods and systems of the present invention may be used in optimizing digital video encoders and decoders.
摘要:
Methods and systems for obtaining a motion vector between two frames of video image data are disclosed. Specifically, methods and systems of the present invention may be used to perform a block-matching algorithm over a two-dimensional search area in a manner that reduces number of comparisons. In particular, the method determines a best candidate block for each strip based by searching in a first dimension of a two-dimensional search area and based on a predetermined difference criterion. The method then determines a second set of best candidate blocks by performing a limited search in the other direction based on the results from the search in the first dimension. The method then determines a motion vector for the best candidate block. Integral projection arrays may be used to further optimize the search. The methods and systems of the present invention may be used in optimizing digital video encoders, decoders, and format converters.
摘要:
A system and method to decode encoded video images in such a manner as to maintain high quality images while reducing the computation time needed to decode the images. The system takes into account that the resultant display generated may only have a fraction (1/16) of the resolution of the original image. Thus, optimizations are realized by modifying the inverse discrete cosine transform (IDCT) and inverse weighting (IW) processes to process only the portion of the image to be displayed.
摘要:
According to the present invention, when an ATV signal is recorded by a digital VCR in the conventional television signal record mode, variable speed reproduction data composed of HP data containing I frame is redundantly recorded in a surplus record area that is formed by the difference between the transmission rate of the ATV signal and the transmission rate of the conventional compressed digital video signal. When variable speed reproduction is performed, the variable speed reproduction data is reproduced.