| 摘要 |
PURPOSE: A system for automatically focusing of a video camera is provided to extract a high frequency component of a brightness signal of each pixel among image information with a hardware method and automatically control a focus of the video camera using the extracted high frequency component. CONSTITUTION: A system for automatically focusing of a video camera includes an analog /digital transformation part(110), a multiplexer part(120), a space high frequency filter part(130), a multiplication part(140), a comparison division part(150), and a focus control part(160). The analog/digital transformation part is to transform a brightness signal of each pixel offered an output from an image signal processing part of a video camera into a digital signal and offer an output. The multiplexer part is to select an established one bit value only among a large number of bit values of a brightness signal offered an output from the analog/digital transformation part and offer an output. The space high frequency filter part is to make a space high frequency filtering an output value of the multiplexer part with a filter coefficient of 3X3 structure to offer an output the high frequency component value of a brightness signal of a corresponding pixel. The multiplication part is to multiply the output value of the space high frequency filter part to a brightness signal value of a predetermined pixel to offer an output. The comparison division part is compare an output value of the multiplication part with an established first standard value, repeat an operation stacking the output value for total pixel of one field screen when the output value is larger than the established first standard value and offer an output a stacked data. The focus control part is to compare the stacked data with an established second standard value and fix or move a focus lens in the present position according to the result of the comparison. |
