Text and enhancing technique integrated into decoding or inverse quantisation required by JPEG standard - using two different quantisation tables one for use during compression and other for use during decompression process

Patent Assignee: HEWLETT-PACKARD CO (HEWP )

Inventor: BERETTA G; BHASKARAN V; KONSTANTINIDES K

Number of Countries: 004 Number of Patents: 002

Patent Family:

Patent No	Kind	Date	Week
EP 735771	A2	19961002	199644 B
JP 8289324	A	19961101	199703

Local Applications (No Type Date): EP 96103595 A 19960307; JP 9642751 A 19960229

Priority Applications (No Type Date): US 95411369 A 19950327

Abstract (Basic): EP 735771 A

The device for transmitting colour images uses a scanner to render a colour image into colour source image data representing the colour image. A compression device compresses the source image data. The compressor has a transformer for converting the source image data into transformed image data. Q tables store a first multi-element quantisation table (QE). A quantiser converts the transformed image data into quantised image data in accordance with elements contained in the first quantisation table. Scaled Q tables store a second multi-element quantisation table (QD) nonidentical to the first quantisation table. An entropy encoder transforms the quantised image data into the encoded image data using an entropy table. The encoded image is encapsulated with the second quantisation table and the entropy table to form an encapsulated data file. The encapsulated data file is then transmitted.

USE/ADVANTAGE - Computationally efficient method for improving visual quality of images and in partial text in scanned images.