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:
Oct. 31, 2000
Filed:
Dec. 31, 1997
Larry Pearlstein, Newtown, PA (US);
Sharif M Sazzad, North Brunswick, NJ (US);
Hitachi America, Ltd., Tarrytown, NY (US);
Abstract
Methods and apparatus for combining linear image post-processing operations with an inverse discrete cosine transform (IDCT) operation are described. In accordance with various embodiments of the present invention IDCT and downsampling operations are combined into a single operation to achieve the same image processing result as sequential IDCT and downsampling operations. By combining the two operations and performing downsampling in the DCT, as opposed to pixel domain, significant complexity reduction is achieved over embodiments where the two operations are performed sequentially. In one particular embodiment, when interlaced images are being processed, combined IDCT/downsampling circuits which perform field based, as opposed to frame based, downsampling in the DCT domain are employed. The method and apparatus of the present invention can be used to implement circuits which perform a combined full order IDCT/downsampling operation and/or a reduced complexity combined full order IDCT/downsampling operation. The combined IDCT/downsampling methods and apparatus of the present invention are capable of supporting a wide range of downsampling ratios using, at least in some cases, fewer math operators, than are required to implement zonal filtering followed by a reduced order IDCT operation which requires the use of a contiguous subblock of DCT coefficients.