A polynomial-time On2 algorithm is presented for extracting the boundary rectangles from a given interval template having no “inner windings.” The algorithm involves only comparisons and list operations. The performance of the algorithm is tested and compared with those of four boundary extraction algorithms existing in the QFT literature. The testing is done on a benchmark suite of eleven transfer function examples, using computational time and effort (flops) as the performance metrics. The test results show the proposed algorithm to be superior in every example. The typical improvement in terms of these metrics is by several orders of magnitude.

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