Image processing system

An image processing system comprising:

• image reducing unit for generating a plurality of reduced image data obtained by reducing a plurality of image data, the plurality of image data being obtained by photographing the same photographing range at the same photographing time using a plurality of cameras arranged at different positions for stereo photographing;
• first parallax calculation unit for calculating a parallax using the plurality of reduced image data;
• parallax calculation region determining unit for determining a parallax calculation region for calculating a parallax on image data formed prior to reducing the image data, based on the parallax calculated from the reduced image data by the first parallax calculation unit;
• and
• parallax calculation unit that calculates a parallax in the parallax calculation region on the plurality of image data formed before image reduction, and uses the calculated parallax as the parallax of the image data formed before image reduction.