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. 03, 2002
Filed:
Jan. 23, 1998
Kokusai Denshin Denwa Kabushiki Kaisha, Tokyo, JP;
Abstract
This invention aims to provide a method and apparatus for detecting a synchronization shift in which the synchronization shift between an original image and a reproduced image can be accurately detected even if noises are generated by a video codec or the like. An original image sent out from an image source has a sine wave for synchronization overwritten thereon in a frame memory. The image on which the sine wave has been overwritten is decoded in a codec and stored in another frame memory. The two images srored. in two frame memories are simultaneously started to be read out. From the image from the other frame memory, only the sine wave is extracted in a notch filter, subjected to an offset correction in an adder, and inputted to asynchronization shift detecting unit. The synchronization shift detecting unit uses the sine wave to detect line, frame and horizontal pixel shifts. Since a sine wave is used as a synchronization marker and only the sine wave is extracted in the notch filter, the synchronization shift can be accurately detected.