Automatic detection of edges of hardness measurement impressions - involves maximum contrast illumination video imaging and evaluation by threshold comparison, then differentiation of contour pulses

摘要

The method for the automatic detection of the edges of hardness measurement impressions in workpieces involves illuminating the workpiece to produce a maximum contrast change at the edges, acquiring an image of the impression with a video camera, feeding the video signal to a comparator with a contrast level, differentiating the signal and storing the resulting contour pulses and deriving geometric data from them. The geometric data are derived by computer, e.g. to obtain a diagonal of the impression or its surface area. ADVANTAGE - Automatic evaluation of results to be improved.