Accelerated detection of image objects and their orientations with distance transforms

摘要

Abstract: A new approach is developed for detection of image objects and their orientations, based on distance transforms of intermediate level edge information(i.e., edge segments and vertices). Objects are modeled with edge segments and these edges are matched to edges extracted from an image by correlating spatially transformed versions of one with a distance transform of the other. Upper bounds on change in cross- correlation between edge maps and distance transforms are shown to be simple functions of change in translation and rotation. The process of computing the optimal object rotation at each possible translation can be accelerated by one to two orders of magnitude when these bounds are applied in conjunction with an object translation-rotation traversal strategy. Examples with detection and acceleration results demonstrate the robustness and high discriminatory power of the algorithm.!