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:
Jul. 05, 1994
Filed:
Mar. 23, 1992
Robert F Miller, Modesto, CA (US);
Steven M Blonstein, San Jose, CA (US);
Ricoh Company, Ltd., Tokyo, JP;
Ricoh Corporation, Menlo Park, CA (US);
Abstract
In an image compression system using a typical image compression scheme, a pointer array is provided to point to each of the many MCUs in a compressed image file. From all the blocks of an image, a subset of the blocks is selected as a virtual image. The virtual image is edited, and each edited block is compressed into an edited block. The edited block is compressed into an edited MCU and placed in an edited block region, and the pointer to the original MCU is changed to point to the new MCU. In this way, the pointer array can be modified to perform an Undo operation. An edge table is provided to hold values where each value, when combined with the differential value for a block on the edge of the virtual image, provides an absolute value for the block without reference to blocks beyond the edge of the virtual image. The entries in the edge table are determined from the compressed MCUs without the blocks being fully decompressed. More than one edge table can be provided. In an image editor, a virtual image is decompressed from a compressed image, the virtual image is processed, and recompressed. The recompressed, edited blocks are then placed in a edited block memory.