Multi-scale optical image processing

The authors introduce two multiscale optical image processing systems, a centroid scale-space processor and an optical wavelet processor. A.P. Witkin (1984) introduced the idea of scale-space, where information is presented on a coordinate system with continuous spatial and scale axes. His representation consists of a convolving the input signal with a Laplacian of a Gaussian point spread function and retaining the zero-crossings (which correspond to edges) as scale (width of the Gaussian) is varied. These edge maps form continuous contours in scale-space. The optical implementation of the system is discussed. The centroid scale-space map (CSSM) is constructed. This technique is extended to 2D input functions by using correlation techniques. The optical system which computes a 2D wavelet transform is shown. One special advantage is that the system complexity is independent of the scale parameter. This gives the flexibility to tailor the scale parameter to the particular application