| 摘要 |
PURPOSE:To track a target or a scene stably, by eliminating the lowering and the fluctuation of the power ratio of noise to signal of correlation coefficients due to DC components by obtaining an average value of the video signal of a face to be correlated in the horizontal direction and the vertical direction respectively and subtracting the average value from the video signal to extract only AC components. CONSTITUTION:The video signal from a pickup device 6 is digitized by an A/D converting circuit 7, and faces to be correlated in horizontal and vertical directions are extracted by a region dividing circuit 8, and average values are detected by horizontal and vertical average value detecting circuits 9H and 9V. These average values are applied to subtracting circuits 10H and 10V, and average values are subtracted from the video signal divided by the circuit 8. Next, horizontal and vertical switches 11H and 11V are used to store preliminarily reference pictures in horizontal and vertical memories 12H and 12V, and coefficients of correlation between video signals of reference picture and video signals of newly inputted pictures to ne correlated are calculated by horizontal and vertical correlators 13H and 13V. Maximum values from horizontal and vertical maximum value detecting circuits 14H and 14V are fed back to the circuit 8 to move stably positions of pictures to be correlated. |
