| 摘要 |
PROBLEM TO BE SOLVED: To precisely detect a foreground region by counting all pixels included in an object region and pixels which have been changed, and determining whether the object region is the foreground region or not. SOLUTION: A change detector 106 compares a current frame taken out of a current frame memory 100 with a previous frame from a previous frame memory 102 to detect a changed region in the current frame. The absolute value of a difference between a luminance value for each pixel of the current frame and a luminance value for a corresponding pixel in the previous frame is calculated first and compared with a 1st threshold value Th1. When the absolute value is larger than or equal to Th1, the given pixel is included in the changed region. A changed region signal is supplied to a foreground/ background area decision unit 110 through a line L10 and the decision unit 110 counts the changed pixels with area information from an area detector 104 and the area signal from the detector 106. Then the foreground area can be determined according to the number of all the pixels and the number of the changed pixels. |
