Patent ID: 8170344

Claim:
An image storage device comprising: an image data storage unit configured to store image data by using lossy compression; a drawing unit configured to generate color information and drawing coordinates information of a drawing command; an attribute information storage unit configured to store attribute information of each pixel of the image data by using lossless compression; a background recognizing unit configured to recognize a background portion of the image data, the background recognizing unit including, a background color recognizing unit configured to recognize a background color based on the color information generated by the drawing unit, and a background pixel recognizing unit configured to recognize whether each pixel corresponds to the background based on the drawing coordinates information of a drawing command generated by the drawing unit; an attribute-information generating unit configured to generate background information of each pixel, the respective background information indicating whether each respective pixel is part of the background portion of the image data; and a background image processing unit configured to switch between image processing functions for an output according to the background information generated by the attribute information generating unit.