The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 27, 2001
Filed:
May. 31, 1994
Steven Marshall Hancock, Boca Raton, FL (US);
Mark Andrew Pietras, Boca Raton, FL (US);
Leslie R. Wilson, Boca Raton, FL (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A digitized image compression system employs several different compression techniques to compress the luminance and chrominance information and encodes the selected technique “on the fly” by inserting selected escape and header codes into the encoded data stream. More particularly, during compression, each image is divided into non-overlapping contiguous regions, referred to hereinafter as blocks and image data is compressed on a block-by-block basis. Each encoded block begins with a one-byte header that indicates, in conjunction with a previous escape code, the compression technique which was used to encode the block. Therefore, interpretation of the encoded data is a hierarchical process: the escape codes indicate a stream interpretation mode which, in turn, determine the meaning of header values which follow and the header values, in turn, determine the meaning of the encoded data in each block. The majority of image blocks are divided into quadrants and each block header is arranged as a sequence of four two-bit codes which indicate the encoding used for the four quadrants within the associated block. However, certain combinations of encoding that are unlikely to occur within the same block are inserted into the image data stream as the “escape codes” which designate the stream interpretation mode.