1. A method of measurement of tool dimensions which uses an image capture device which moves relative to a tool to capture an image of said tool and which uses the obtained image data to measure dimensions of said tool, the method of measurement of tool dimensions comprising the steps of: using image data of part of the contour of said tool captured by said image capture device as the basis to specify a partial contour of said tool, using said specified partial contour as the basis to make the field of view of said image capture device move in a direction of the contour of said tool outside of the field of view of said image data, and outputting movement commands for making said image capture device and said tool move relative to each other so that the field of view of said image capture device moves in the determined direction of movement of said field of view.