PURPOSE: To attain stable automatic tracking of an object by introducing an item of feature element extract data obtained by a gene algorithm as an arithmetic operation condition when a deviation between a reference histogram of the object to be automatically tracked and a detection histogram is obtained.

CONSTITUTION: A digital camera processing circuit 8 gives color difference signals R-Y, B-Y as an object tracking detection signal S4 to a tracking control circuit 11. A tracking signal processing circuit 16 obtains a histogram based on a color difference signal H and a saturation signal S from a picture memory 15 and outputs a tracking signal S5 based on the frequency characteristic. Succeedingly, the circuit 16 extracts feature element extract data so that a ratio of a Euclid distance between a center frame in which an object is set and other measurement frames is highest by using a gene algorithm. A measurement frame having a largest similarity is evaluated to have an object therein by using the element extract data. Thus, a background picture and an object picture are clearly separated and sure automatic tracking is attained.