Patent ID: 7460128

Claim:
An image drawing apparatus in communication with a host and for conducting a data transfer at a bit unit for image data stored in a memory device, comprising: a region storing part storing based upon a single coordinate instruction from the host, coordinate information of a single inside region of the image data where at least one attribute value concerning a pixel is not constant in the image data; an attribute value storing part storing each attribute value of pixels in the single inside region; a constant value storing part storing a constant value as the attribute value; an inside region determining part determining whether a coordinate being transferred is within the single inside region; a selection signal generating part generating a selection signal selecting reading an attribute value from the attribute value storing part and/or from the constant value storing part, based on the determining of whether the coordinate is within the single inside region; and reading the attribute value from the selected storing part for processing the source image data, wherein the inside region determining part further comprises: a first comparison determining part determining whether the coordinate being transferred is within the single inside region by comparing a X coordinate being transferred with a first minimum value and a second maximum value of a X coordinate of the single inside region stored by the single coordinate instruction from the host, respectively, and a second comparison determining part determining whether the coordinate being transferred is within the single inside region by comparing a Y coordinate being transferred with a first minimum value and a second maximum value of a Y coordinate of the single inside region stored by the single coordinate instruction from the host, respectively, wherein the coordinate being transferred is within the single inside region when both results from the first comparison determining part and the second comparison determining part are within the single inside region.