Importance

Loading Importance Indicators...

Abstract

In a high speed video capture and display system including an N.sub.channels channel sensor for producing N.sub.channels parallel analog video signals, N.sub.channels signal processing channels for processing the analog video signals, each of the N.sub.channels signal processing channels including an analog-to-digital converter (ADC) having gain and offset which are controlled by controlling the common mode and differential voltages across each ADC ladder network; and a central processing unit for controlling the gain and offset by means of digital control signals; the method of calibrating the system to produce a uniform image comprising the steps of. a) illuminating the sensor with a broadband and spatially uniform light source to determine L.sub.max ; b) initially setting the common mode and differential voltages of each ADC to nominal settings; c) illuminating the sensor with a spatially uniform broadband illumination N.sub.illum evenly spaced illumination levels; d) for each of the illumination levels collect for each of the N.sub.channels, N.sub.samples of spatially distributed pixels; and e) for each channel find the gain m.sub.j and the offset b.sub.j ; f) calculating the desired corrections in gain k.sub.mj and offset .DELTA..sub.bj by finding the specific channel whose gain m.sub.l represents the median gain value among the set of gains m.sub.j for all channels and for all channels computing k.sub.mj and .DELTA..sub.bj ; g) calculating and applying the desired correction in the digital common mode and span controls over all channels; and h) repeating steps b-g until convergence is reached.

Loading the Abstract Image...

First Claim