Real-time transformation of incoherent light images to edge- enhanced darkfield representation for cross-correlation applications

摘要

Cross-correlation of an image with a reference pattern is done in order to determine recognizable content and gives a sharp correlation peak whenever both image and pattern are edge-enhanced, darkfield representations. Incoherent light, conventional optics and electronics are used to obtain edge- enhanced, darkfield representations which are obtained by sending the light from the object through a dual-aperture unit to a lens so that a recording medium located forward of the focusing plane of the lens will receive light blocked alternately by the regular (perimeter) stop and the central stop and will record the difference.