Means which enables image conversion in which a plurality of conversion results can be output without once saving all of video-image data, which has been input from image-pickup means, in a storage medium is provided. A single line memory having a plurality of lines is used while switching the role thereof for a reading use by a video-image converting means and a use for inputting image data from the image-pickup means. The image converting means obtains an input image, which is in the line memory, and carries out conversion of the input image based on a conversion specifying means interpreted by an instruction decoder.