Spent the last few days on the sample bgfg_codebook. At this point, slowly examined the source code of the sample program - which exercises the functions of a cvaux module: cvbgfg_codebook. Have yet to run the program yet. During such course, explored a little bit on dynamic storage provided by CVCore. The MemStorage and CVSeq. Other topics that is touched on is the built-in contour tracing, supposedly the same as edge-detection/perimeter-finding. The ApproxPoly() function uses something called Douglas-Peucker algorithm to reduce the number of points needed to represent a curve. Wonder if that is what Inkscape does to 'Simplify Path'. Amazed by the depth of this openCV library.