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:
May. 25, 1999
Filed:
Jan. 17, 1997
Naoto Yamamoto, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Picture data into small-area blocks, which are then shuffled. The shuffled picture data is then subjected to orthogonal transform. A total-frequency-range activity of transform coefficients is calculated on a block-by-block basis and accumulated over a slice. A high-frequency-range activity of the transform coefficients is calculated on a block-and-block basis and accumulated over the slice. Selection is made between a block quantization step which is calculated from the total-frequency-range activity of a block and a slice quantization step which is calculated adaptively from the total-frequency-range activity accumulation value of the slice. A quantization step to be used in actual quantization is determined by using the sum of the selected quantization step and a difference quantization step.