| 摘要 |
<p>A method and apparatus for correlating two signals representing a live image and a reference image are disclosed. The reference signal is processed to provide a polarity bit and mask bit for each pixel position in the reference image. The processed video signal is stored in a memory (20) and used in a convolver and summer section (18) in which the polarity bits between the reference and live images are gated by gate (17) and are used in generating a correlation output from summer (23). However, the polarity bits do not affect the correlation output if the logical output from gate (19) is of a given state which occurs if the associated mask bits indicate that the gradient value at the particular pixel position does not exceed certain minimum threshold values.</p> |
