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:
Feb. 24, 2004
Filed:
Mar. 08, 2000
Nobuaki Abe, Hokkaido, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An image compression and expansion apparatus obtains an average value of a single block (8×8 pixels) in a first matrix (64×64 pixels) of the original image data, to generate reduced image data of a second matrix (8×8 pixels). A sub-matrix, which is displaced from the second matrix by a predetermined amount, is obtained in such a manner that a pixel of the second matrix is contained in the sub-matrix. 8×8 pixels of the sub-matrix are subjected to a two dimensional discrete cosine transformation, to obtain reduced DCT coefficient data. The reduced DCT coefficient data is subjected to an expanded inverse discrete cosine transformation to obtain expanded image data of a matrix (m×n pixels). The displacement direction and the displacement amount of the sub-matrix relative to the second matrix, and the values of “m” and “an” are selected in such a manner that the expanded image data becomes as close to the original image data as possible.