(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2003/0185437 Al
Nakami (43) Pub. Date: Oct. 2,2003
(51) Int. CI.7 G06K 9/00
(52) U.S. CI 382/162
When JPEG data is open on a personal computer 10, YCbCr to RGB conversion is carried out. The converted RGB data may include negative color values and color values ol and over 256, which are outside ol a 0 to 255 color value range in the sRGB color space generally used on the personal computer 10. The negative color values and the color values of and over 256 included in the RGB data are linearly compressed into color values in the 0 to 255 color value range, are subjected to image processing, and are then linearly expanded. This arrangement effectively reduces deterioration of the image processed RGB data relative to the original RGB data.