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. 07, 1999
Filed:
Dec. 29, 1997
Mutsumi Ohta, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The invention provides a coding system and a decoding system wherein a discrete cosine transform which provides a high coding efficiency is approximated to allow reversible coding and decoding while maintaining the high coding efficiency and a system which includes such coding and decoding systems. Reversible coding is realized by multiplying a transform matrix by a fixed number for each row to approximate the transform matrix with integer values, performing re-quantization in a basic region defined by a multiple of a determinant for suppressing redundancy while maintaining a condition wherein reversible coding is possible in the basic region, and performing re-quantization for the entire region making use of the fact that such basic region appears periodically in a signal space.