首页>
外国专利>
CCD dark mean level correction circuit employing digital processing and analog subtraction requiring no advance knowledge of dark mean level
CCD dark mean level correction circuit employing digital processing and analog subtraction requiring no advance knowledge of dark mean level
展开▼
机译:采用数字处理和模拟减法的CCD暗均值校正电路,无需事先了解暗均值
展开▼
页面导航
摘要
著录项
相似文献
摘要
A digital black clamp circuit for calibrating the black level of an image signal produced by an imaging device, such as a CCD sensor. The digital black clamp circuit comprises a source of a video signal having a first interval of black level pixels and a second interval of image pixels; a differential amplifier having first and second inputs and an output, wherein the source is coupled to one of the first and second inputs; an A/D converter coupled to the output of the differential amplifier; a digital signal processor coupled to the A/D for accumulating and averaging digital black level pixels; a D/A converter coupled to the digital signal processor; and a control for selectively uncoupling the D/A converter to the other of the first and second inputs of the differential amplifier during the first interval of the video signal; and for coupling the D/A converter to the other of the first and second inputs during the second interval of the video signal to clamp the image pixels to an average black level.
展开▼