An image processing apparatus includes an inputting unit for inputting moving image data that is composed of frames each including first and second fields and that is encoded by intra-frame and inter-frame encoding; an instructing unit for submitting a request for outputting a still image; a still image generating unit for generating still image data including first encoded data and second encoded data, each of these encoded data having a prediction error of zero with respect to a reference image; a multiplexing unit for selecting to output either the still image data generated by the still image generating unit or the moving image data input by the inputting unit; a controlling unit for controlling the multiplexing unit so as to select the still image data generated by the still image generating unit; and a transmitting unit for transmitting the image data output from the multiplexing unit in an encoded state.