Patent ID: 8538075

Claim:
An apparatus comprising: a processor; and a memory coupled to the processor, the memory having instructions that, when executed by the processor, perform operations comprising: classifying pixels existing inside a tracking target area set on an image and pixels existing outside the tracking target area according to an attribute and storing a result of classification of the pixels on a storage medium; deriving a first ratio of the pixels existing inside the tracking target area and having the attribute to the pixels existing outside the tracking target area and having the attribute; deriving a second ratio of pixels, of the pixels existing inside the tracking target area, whose the first ratio is higher than a first predetermined value, to all pixels existing inside the tracking target area; and determining, if the second ratio is higher than a second predetermined value, that the tracking target area can be tracked, wherein the first predetermined value when a color pixel is achromatic is stricter than the first predetermined value when the color pixel is chromatic.