In one embodiment, an image sensor includes, a bank 301 of charge-coupled devices, and charge sensing amplifiers 302, each of which transforms electric charges extracted from an associated pixel into an electrical signal. After the electric charges accumulated in every pixel have been extracted to the charge-coupled devices 301 at the same time, a color component with a high resolution is output to a horizontal transfer path 316 via the charge sensing amplifiers 302 and then output to a device outside of the image sensor. Thereafter, pixel signals representing another low-resolution color component are vertically added together on the bank 301 of charge-coupled devices. Those pixel signals are horizontally added together on the horizontal transfer path 316 and output. The image obtained by this image sensor is then input to an image processing section, thereby obtaining an output color image with a high resolution and a high frame rate.