APPARATUS AND METHOD FOR REMOVING OFFSET AND SHADING FROM A VIDEO SIGNAL

摘要

An apparatus and method for removing offset and shading from a video signal include a filter (28) that convolves the video signal (12) with a second derivative (Fig. 4). The derivative can include first and second non-zero values centered about a third non-zero value, zero-filling between the first and third values, and zero-filling between the second and third values. The filter (28) can be applied to Modulation Transfer Function measurement of an electro-optical sensor, in which offset and shading are removed from the sensor's video signal prior to Fourier analysis. Filtering and Fourier analysis are performed by a digital signal processor (26), which allows the measurement to be fully automated.