Patent US 5,764,809

An image processing apparatus comprises a CPU, an information input unit, a main storage made up of a RAM, an image input interface, a display interface, and a ROM. These components are mutually connected on a bus. The CPU includes an image processor which operates according to programs stored in the ROM. The image processor comprises a corresponding point detector for detecting corresponding points in multiple images, an image matching unit for matching at least two images according to the output result of the corresponding point detector, and an image synthesizer for synthesizing at least part of at least one image portion matched by said image matching unit with at least part of image information of other images to form a single image. The information input unit is a keyboard for entering the type of an electronic endoscope and other data. The image input interface is connected to image memories and receives image data from the memories.