Accurate Local Form And Motion Extraction By A Composite 1st And 2nd Difference Processor Based On An Interpretation Of Human Vision.

Over the last two or three years the adequacy of the classical 2nd difference zero-crossing approach to edge detection in computer vision has been questioned. It has been shown that zero-crossing analysis can lose data or introduce artifacts in some situations. Although the 2nd difference approach is largely driven by the fact that human vision appears to process in 2nd difference space the present authors have concluded that perceptual behaviour is best explained as being controlled by 1st differences of luminance. Starting with a basic set of building blocks from our interpretation of human early visual function a computer simulation has been assembled which derives very simply and directly both 1st and 2nd difference maps of the input scene, both of which exhibit super-resolution capabilities. This paper describes the simple processing sequence which permits such maps to be simply derived. It is shown that the 1st difference map is free from ambiguities and contains both profile and shading data, whilst the 2nd difference map, when cued from the 1st difference map, can yield unambiguous and highly accurate motion and stereo information by simple analysis of pairs of frames.