Abstract: 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.

Abstract: A fast frame recorder records images of an event at a fast frame rate and plays back the images at a slower frame rate to facilitate analysis of the event. Disclosed is a solid state fast frame recorder having a solid state imager, which is selectively operable at different frame rates and having a solid state memory for storing a plurality of image frames. A programmable control system controls the memory to store temporally nonconsecutive images from the imager according to a preselected program. Both temporally nonconsecutive single image frames and bursts of temporally consecutive image frames may be stored. The number of image frames in a stored burst and the frame rate of the stored burst may be selectively varied.