ADAPTIVE PROCESSING FOR IMAGES OF PAGES OF A DOCUMENT

An image processing apparatus has a compression rate predicting section for computing an improving rate of compression required for storing image data of the entire document in a image data storage section, and a compression rate correction table for storing a change table for changing the reference values for bi-level processing based on the improved rate computed by the compression rate predicting section in its image processing section. In a case where storage capacity is short while the document image data is stored in the image data storage section, image processing is applied to image data in image data processing section by the compression rate predicting section and the compression rate correction table so that the compression rate is improved. Thereby, compression rate of image data is improved and the image data of the entire document is reliably stored in the image data storage section.