US Patent 7813530 Motion detecting method and apparatus

A motion detection apparatuses and method where a characteristic region is extracted from an image produced by an imaging device are described. A modified region is formed by modifying the characteristic region. Voting occurs so as to count up to increase a count value at a memory address corresponding to a location inside the modified region and to reset a count value at a memory address corresponding to a location outside the modified region. At least one of the moving direction and the moving speed of the modified region is calculated based on a difference among accumulated count values for adjacent locations. The position of the modified region can be calculated based on count values and locations in the modified region.