The invention is characterized by the fact that an area sensor for outputting an analog signal responsive to the light reception amount of light of CMYG is used and when CMYG image data is converted into RGB image data, RGB image data having a domain also in negative values is generated without performing processing of putting the RGB image data into values of 0 or more, without decreasing the information amount of the CMYG image data. Further, the invention is characterized by the fact that when the image data is recorded in a file section 16 finally as a JPEG file, the pixel data of each color of YCbCr is represented as data type of eight bits and the information amount per pixel is 24 bits for recording more color information without increasing the memory capacity.