An image-signal processor may be provided to support CCD image sensors. A timing generator may provide timing signals to CCD image sensors, to enable each of the CCD image sensors to output captured-image data in form of an analog signal that a corresponding A/D converter converts into a CYMG signal. Image-processing parts may receive the CYMG image signal from the A/D converter and convert the CYMG image signal into an YCbCr signal. An image-combination part may combine horizontally or vertically images in form of the YCbCr signal into a combination image and store the combination image in an internal memory, and scale down horizontally or vertically the combination image while reading out the combination image from the internal memory, storing the scaled-down combination image in an external memory, and outputting the scaled-down combination image in form of an YCbCr signal.