JPS6462779A - Shading correcting circuit for image sensor - Google Patents

Abstract

PURPOSE:To easily and quickly perform the shading correction operation to satisfactorily cope with shading even in on-line by using hardware to digitally execute the shading correction. CONSTITUTION:A video signal Vp from a TV camera 10 is converted to a digital signal Vd by an A/D converter 16, and a synchronizing signal HS2 and a clock signal CLK are separated from the signal Vp and are inputted to a counter 17. The counter 17 counts the clock CLK for each picture element in order from a part A of a line sensor incorporated in the TV camera 10 and its counted value (n) is increased up to a part B. An integral value N of the counted value (n) is inputted as the address to a memory 18, and a correction function F(N) is stored in the memory 18 correspondingly to each picture element, and a correction value Cn corresponding to (n), namely, the address input N is outputted. A multiplier 19 multiplies the digital signal Vd and the correction value Cn and outputs a correction signal Vo3. Thus, shading correction is accurately and quickly performed to satisfactorily cope with shading even in on-line.