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:
Dec. 19, 1989
Filed:
Oct. 21, 1987
Joan L Mitchell, Ossining, NY (US);
Karen L Anderson, Peekskill, NY (US);
Gerald Geortzel, White Plains, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for encoding and decoding digital image data, includes the steps of: testing the data for a vertical relationship between adjacent lines of the image; generating directly a reference code word representative of the vertical relationship for each successful test; generating by table lookup a run code word for a stream of data bits of common value for each unsuccessful test whereby a data element representing a number of bits in a code word is stored at a predetermined offset from a table entry for the code word; merging the vertical reference code words and the run code words generated by the above steps to form an encoded data stream; testing the encoded data stream for a reference code; decoding directly the vertical relationship from the reference code for each successful test; decoding by table lookup a run of bits of common value by serial examination of said encoded data stream for each unsuccessful test; and storing data decoded by the above steps in a predetermined relationship. A fast algorithm for modifying an image in run representation form before encoding or after decoding is also described.