Outputs of pixels present around a given pixel at an image-capturing unit having a plurality of pixels disposed two-dimensionally are added to the output of the given pixel. During this process, the addition pattern with which the pixel outputs are added together is determined in correspondence to a specific type of image processing to be executed at a subsequent stage, and an image is generated by adding together the pixel outputs constituting image signals output from the image-capturing unit based upon the addition pattern. The image resulting from the addition then undergoes the image processing and the processed image is output.