Method and apparatus for coding motion pictures
First Claim
1. An apparatus for compressing a motion picture comprising a sequence of frames, each said frame comprising a two-dimensional image representing said motion picture at one instance in time, said apparatus comprising:
- means for receiving a signal specifying a compression ratio for said motion picture;
means for receiving signals specifying said frames;
means for storing a predetermined number, Nt of consecutively received said frames;
three-dimensional filtering means for filtering said stored frames to generate a plurality of three-dimensional component images, said plurality of three-dimensional component images comprising a low-frequency component image and one or more high-frequency component images, each said component image comprising a plurality of pixel values; and
quantization means for approximating each pixel values in at least one of said component images by an approximation comprising one of a predetermined set of integer values, the precision of said integers being related to the statistical distribution of the pixel values in said component image and said received compression ratio; and
means for generating output signals specifying said pixel approximations.
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Abstract
A method and apparatus for compressing motion pictures is disclosed. The frames of the motion picture are divided into adjacent groups. Each group is treated as a three-dimensional image. The three-dimensional image is then filtered via a three-dimensional FIR filter to generate three-dimensional component images that are more efficiently quantized. The degree of quantization of each component image is determined in part by the spatial frequencies represented by the component image in question. For motion pictures derrived from interlaced scanning devices, the quantization of specific component images is altered to prevent artifacts.
109 Citations
17 Claims
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1. An apparatus for compressing a motion picture comprising a sequence of frames, each said frame comprising a two-dimensional image representing said motion picture at one instance in time, said apparatus comprising:
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means for receiving a signal specifying a compression ratio for said motion picture; means for receiving signals specifying said frames; means for storing a predetermined number, Nt of consecutively received said frames; three-dimensional filtering means for filtering said stored frames to generate a plurality of three-dimensional component images, said plurality of three-dimensional component images comprising a low-frequency component image and one or more high-frequency component images, each said component image comprising a plurality of pixel values; and quantization means for approximating each pixel values in at least one of said component images by an approximation comprising one of a predetermined set of integer values, the precision of said integers being related to the statistical distribution of the pixel values in said component image and said received compression ratio; and means for generating output signals specifying said pixel approximations. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An apparatus for decompressing a compressed motion picture, said compressed motion picture comprising a sequence of approximations for the pixels of one or more three-dimensional images, said decompression apparatus comprising:
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means for receiving a signal specifying said pixel approximations; means for generating one or more three-dimensional component images from said received pixel approximations including means for generating blank pixel values for any said pixel value not received; inverse three-dimensional filtering means for combining said three-dimensional component images to generate a plurality of two-dimensional luminance picture frames; means for generating output signals specifying said generated luminance picture frames; - View Dependent Claims (8)
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9. A method for compressing a motion picture to a given compression ratio, said motion picture comprising a sequence of frames, each said frame comprising a two-dimensional image representing said motion picture at one instance in time, said apparatus comprising:
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receiving signals specifying said frames; storing a predetermined number Nt of consecutively received said frames; filtering said stored frames to generate a plurality of three-dimensional component images, said plurality of three-dimensional component images comprising a low-frequency component image and one or more high-frequency component images, each said component image comprising a plurality of pixel values; and approximating each pixel values in at least one of said component images by an approximation comprising one of a predetermined set of integer values, the precision of said integers being related to the statistical distribution of the pixel values in said component image and said compression ratio; and generating output signals specifying said pixel approximations. - View Dependent Claims (10, 11, 12, 13, 14)
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- 15. A recording of a motion picture comprising a plurality of ordered frames, said recording comprising means for storing a plurality of digital values, said digital values being divided into groups, each said group comprising approximations for the pixels of one or more component images, said component images specifying a three-dimensional image, each said three dimensional image comprising information specifying two or more frames of said motion picture, said component images comprising a low-frequency component image and one or more high-frequency component images.
Specification