In this image processing device, an image processing portion 102 performs a predetermined pre-processing on first image data and outputs it as second image data. A judging portion 104 that judges the degree of importance of the first image data on the basis of the characteristics of a subject that is included in the first image data. A reducing portion 105 reduces the data amount of the second image data in accordance with that degree of importance and outputs it as third image data. According to this image processing device, by reducing the data amount of the second image data in accordance with the degree of importance of the first image data, it is possible to achieve greater reductions in the data amount as the degree of importance decreases. As a result, it is possible to more efficiently reduce the power consumption and time required when transferring image data after data reduction.
