US 6,687,410 B1 · Method and apparatus for compression and decompression of data

Abstract

The present invention is a compression scheme for compressing audio and video data. An image is divided into blocks of pixels. In one test, if all of the pixels are approximately equal to the corresponding pixels in the previous block, then no data is sent for that block. In a second test, if all of the pixels in a block are approximately equal to a mean pixel value, then only one color value is transmitted. In a third test, if quantization of the pixels via companding results in an acceptable representation, the quantization is performed. The present invention uses quantization codes that are proportional to the logarithm of the magnitude of the range quantized, computation of a magnitude byte that permits rapid discovery of the number of bits used for quantization of a block, recursive packing and unpacking of quantized pixel data, and two-dimensional paths through the block.

Claims14

Dependent claims

A method for data compression comprising:

defining a block of pixels as a present block;
comparing a characteristic of each pixel of said present block to a corresponding pixel of a previous block;
transmitting no data when each of said pixels of said present block is approximately equal to said corresponding pixels of said previous block;
comparing a characteristic of each of said pixels of said present block to all other pixels of said present block when each of said pixels is not approximately equal to said corresponding pixels of said previous block;
transmitting one byte of data when each of said pixels of said present block is approximately equal to all other pixels of said previous block;
quantizing each of said pixels to a quantized value of said present block when each of said pixels of said present block is not approximately equal to all other pixels of said present block;
transmitting said quantized value when said quantized value is within a predetermined quantization variance.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for compression and decompression of data

Life of this patent

Method and apparatus for compression and decompression of data

Life of this patent

Abstract

Claims14