There is disclosed an image processing apparatus for electrically handling image information, particularly in compressed form, in which the efficiency of memory utilization is improved by storing information of plural pages in successive manner in a memory. Provision is made for ensuring that, if insufficient space is left in the memory for storage of another page of compressed image data, reading of the page in question is interrupted. Once there is again sufficient availability in the memory, the page is re-read, and the read data is compressed and stored.