Image processing apparatus for advantageously encoding blocks of data having either substantially the same or varied colors

摘要

Method and apparatus for efficiently encoding image data of a color facsimile or the like are provided. A specific color judgment unit discriminates a specific color portion such as white or blank portion of the image data inputted from an image input unit. An orthogonal transforming process is not executed to the blank block, thereby raising an encoding efficiency. A discrimination signal is subjected to a dynamic arithmetical encoding, thereby producing code data.