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:
Mar. 16, 1999
Filed:
Jan. 15, 1997
Wei Ding, Fremont, CA (US);
Sun Microsystems, Inc., Mountain View, CA (US);
Abstract
An array of DCT transform coefficients are converted to a two-dimensional array of spatial data in a video compression or decompression system. The array of DCT transform coefficients are divided into two groups. A regional IDCT algorithm is applied to all coefficients, both non-zero and zero, of the first group, while IDCT computation is applied to only non-zero coefficients of the second group. The results of the operations are then combined and/or mapped to form the output array of spatial data. In one specific implementation wherein an 8.times.8 array of DCT coefficients are to be transformed, the first region is defined by the first quadrant of coefficients in the 8.times.8 array. A regional IDCT algorithm is applied to both zero and non-zero coefficients in the first quadrant. The non-zero coefficients in the remaining three quadrants are calculated directly, and the results of the direct calculations are combined with the results of the regional IDCT algorithm applied to the first quadrant coefficients. The resulting values are then mapped to the output matrix.