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:
Jul. 23, 1996
Filed:
Jan. 10, 1995
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
An image signal is divided into pixel blocks, each of which is subjected to orthogonal transform to be converted to transform coefficients. The transform coefficients are divided by respective thresholds set as a quantization matrix to become quantized coefficients. Coding symbols are constructed from the quantized coefficients using a coding symbol table which includes additional coding symbols corresponding to adaptive coding operations. The coding symbols are entropy-coded to become coded information. One of the adaptive coding operations is effected in accordance with identification information that is produced in accordance with a statistical parameter of the pixel blocks. The transform and quantizing operations are stopped during a block run, and after the end of the block run a coding symbol corresponding to the block-run detection is coded. The quantization matrix is switched in accordance with variance of pixel values of the pixel block, and a coding symbol corresponding to the switching of the quantization matrix is coded.