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:
Nov. 03, 1998
Filed:
Mar. 06, 1996
Neri Merhav, Haifa, IL;
Vasudev Bhaskaran, Mountain View, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A method is described for filtering compressed images represented in the discrete-cosine-transform (DCT) domain. The filter includes three sparse, vertical submatrices which are sparse versions of the vertical filter components (VFCs) of a desired filter function that have been combined in such a way as to eliminate many of the non-zero elements. The filter also includes three sparse, horizontal transpose submatrices, which, like the vertical submatrices, are sparse versions of the horizontal filter components of the filter function. The sparseness of these sparse submatrices yields a significant reduction in the number of computations required to filter the image in the DCT domain. To take advantage of this discovery, the input DCT data blocks are 'butterflied' to retain the relationship between the input data blocks and the filtered output data blocks as a function of these sparse submatrices. The sparseness of the vertical and horizontal submatrices reduces the number of computations required to filter the image. The sparseness of the DCT data blocks can also be used to further reduce the number of computations required.