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. 09, 2002
Filed:
Jul. 12, 1999
Kannan Ramchandran, Champaign, IL (US);
Jim Chou, Redondo Beach, CA (US);
Igor Kozintsev, Savoy, IL (US);
Merunetworks, Inc., Santa Clara, CA (US);
Abstract
Method and apparatus for image transmission using arithmetic coding, based on continuous error detection uses a controlled amount of added redundancy. A continuous error detection scheme is provided, wherein there is a trade-off between the amount of added redundancy and the time needed to detect an error once it occurs. Herein, there is no need for the cyclic redundancy check (CRC) to wait until an entire block of data has been received and processed before an error can be detected. The invention can be used to great advantage both in the automatic repeat request (ARQ) and other concatenated coding schemes. Errors in the received bit stream are detected by introducing added redundancy, e.g., a forbidden symbol, in the arithmetic coding operation. The forbidden symbol is never intended to be encoded. The redundancy error causes loss of synchronization, which is used to detect errors. If a forbidden symbol gets decoded, it means that an error has occurred. In this invention, there is direct control over the amount of redundancy added vs. the amount of time it takes to detect an error. For image compression systems, by using the invention and ARQ, only one device would suffice both for source compression and channel coding.