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:
Jan. 01, 1991
Filed:
May. 30, 1989
Hitoshi Ishii, Yokohama, JP;
Ricoh Company, Ltd., , JP;
Abstract
A method applicable to an image filing system or similar system for recording data representative of a halftone image by compressing the data and reconstructing the compressed data. In an input two-dimensional halftone image, the coordinates points where a difference of density changes in the x direction are determined to produce an x direction transition point pattern associated with the coordinates. A y direction transition point pattern is produced by effecting similar processing in the y direction. Further, an AND pattern of the x direction and y direction transition point patterns is generated. The pixels based on the AND pattern are determined to be the characteristic density and are coded, the densities of the other pixels being calculated at the time of decoding. The transition patterns are individually coded by transforming the differences of density data into Huffman codes.