| 摘要 |
A method of and apparatus for discriminating sharp edge transitions produced during optical scanning, as by a CCD or the like, of differently reflective regions of a surface, such as copper conductors and resist background on printed circuit boards and similar applications, through delaying N successive sampling signals defining the edge transition of the desired edge transition regions slope and amplitude from unwanted reflections from other regions, subtracting each camera scan sampling signal from the previous Nth sample signal to produce a large difference signal only for the edge transitions, and adding such difference to the camera output signals to provide a distinctive boost to the edge transition signals which are then thresholded in a manner to insure rejection of signals from unwanted or spurious reflection regions into binary output signals unambiguously indentifying the edge transitions. |
