Patent ID: 8515168

Claim:
An image processing apparatus that performs compression processing for image data, comprising: an image expansion unit that converts image data containing objects into bitmap image data having a predetermined resolution by performing interpolation processing according to a resolution of each object; and a compression unit that losslessly compresses the bitmap image data by converting each of pieces included in the bitmap image into a representative color of each of the pieces and interpolation data of each of the pieces, the representative color being a color of a focus pixel at a certain position of each of the pieces, the interpolation data including information indicating the sameness in color of the pixels in a piece if all of the pixels in the piece are the same in color as each other, and the interpolation data including information about color of pixels other than the focus pixel and information indicating an arrangement of the pixels in a piece if all of the pixels in the piece are not the same in color, wherein the image expansion unit shifts a rendering position of each of the objects in the bitmap image data so that a boundary of rendering a start position of each of the objects matches a boundary of one of the pieces used in the lossless compression of the bitmap image data when the image expansion unit converts the image data containing the objects into the bitmap image data.