Climbing the Contrast Pyramid

A contrast pyramid is a multi-resolution image representation where every levelconsists of a plane multi-graph that is adapted level by level to the contentof the image. The base level is the 4-neighborhood graph of the image. Theequipment to climb the pyramid level-by-level consists of following ingredients:(1) edge contraction and (2) edge removal. Edges have one main attribute: (3)the contrast between the two connected pixels. Edges with contrast zero connectidentical pixels and are contracted rst. Then the contrast of contracted edgesslowly increases up to the top. Novel equipment includes (4) a contrast histogram,(5) a discrete spiral total order, (6) a max-link strategy generating eciently aspanning forest of the image. This contribution explores the main properties thatrelate the top of the pyramid with the features of the lower level image featuresin order to be able to explain the view from the top by the existing properties inthe base.