When a region of interest of an image is compressed with high quality by an
image sensing apparatus, such as a digital camera or the like, the region of interest
(ROI) can be compressed by a compression coefficient different from that of other
regions of the image according to the so-called JPEG 2000 method. However, setting
the ROI is a complicated operation for a user. In the present invention, when a
continuous photographing mode is not set, a single image sensing operation is assumed
and the ROI is automatically set in a first region, which is the largest of three
regions. Whereas in the continuous photographing mode, if a low-speed mode is set,
the ROI is set in a second region smaller than the first region, and if a high-speed
mode is set, the ROI is set in a third region, which is the smallest. In other
words, the ROI is automatically set in the largest region in the single photographing
mode, and when the continuous photographing mode is set, the ROI is automatically
set larger in the low-speed mode than in the high-speed mode.
