Image processing apparatus and image processing method

A method 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.

A computer-readable storage medium storing instructions which, when executed by a computer, cause the computer to execute 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 existence ratio is higher than a second predetermined value, that the tracking target area can be tracked.