Patent ID: 8704888

Claim:
An imaging device comprising: an image pickup portion using a rolling shutter system, an image pickup controlling portion for controlling the image pickup portion so as to pickup at least two frame images by continuous image capturing, each of the images containing a ball image of a ball, the ball image being elliptically deformed, a degree-of-separation calculating portion for calculating a degree of separation of pixels by filtering the frame images captured by the image pickup controlling portion using an ellipse degree-of-separation filter having an inside region of an ellipse shape whose major axis is inclined with respect to a horizontal line and an outside region that is adjacent to the inside region, the degree of separation being calculated between the inside region and the outside region, an estimating portion for estimating a center position, major axis, minor axis and inclination angle of the inside region that results in a maximum degree-of-separation, obtained by the degree of separation calculating portion, by changing the center position, major axis, minor axis and inclination angle of the inside region, as a center position, major axis, minor axis and inclination angle of the ball images, and a state-value calculating portion for calculating a moving-state value of the ball based on each of values of the center position, major axis, minor axis or inclination angle, estimated by the estimating portion, of the ball images in the at least two frame images.