Through analyzing response non-uniformity of visible light area CCD

a kind of system that is used to response non-uniformity detection had been presented

and it is applied to all kinds of area CCD. After radiation scale was done for area CCD485 with this system

the respond relation was established between the gray value of digital image and radiation luminance which integration sphere exported

and responsibility curve was also described. From the digital image that can be gathered

it can be find out the gray value have obvious jump

response non-uniformity has exceeded 5%. When taking pictures under weak light

it will be serious to affect the quality of pictures

so must be rectified. Correction algorithm is selected according to the responsibility curve of area CCD. Because of the area CCD485s responsibility is linear

so here have adopted two-point correction algorithm

calculate the correction factors (gain and offset) of all pixels

and put them into correction matrix. Through multiplication and addition operation

the signal of every pixel is rectified into the average signal of area CCD. Experiment result shows that two-point correction algorithm makes response non-uniformity of CCD485 arrive original 1/10

it is a practical effective method of correction.