Image processing apparatus and image processing method utilizing efficient memory regions

An image processing apparatus comprising:

• a storage unit configured to store image data;
• and
• a control unit configured to ensure a common region in the storage unit, the common region including an input image data storage region and an output image data storage region,
• wherein the image data that is compressed at a preset compression ratio and sequentially inputted is stored in the input image data storage region, and the image data stored in the input image data storage region is sequentially expanded and temporarily stored in the output image data storage region for output,
• wherein the control unit is also configured to control allocation of the input image data storage region and the output image data storage region in the common region, by sequentially releasing a predicted excess memory amount from an initial memory size of either the input image data storage region or the output image data storage region,
• wherein, in response to reading and printing of the image data, the control unit is configured to
• allocate the output image processing region for printing, upon starting of the reading of the image data, and
• allocate, after start of the sequential input of the image data, a portion of the output image data storage region to the input image data storage region to accumulate the image data, in response to the initial memory size of the input image data storage region being of an insufficient size, and
• wherein initially, there is no division between the input image data storage region and the output image data storage region of the common region prior to starting the sequential input of the image data.