Invariant signatures for planar shape recognition under partialocclusion

摘要

A planar shape distorted by a projective viewing transformationcan be recognized under partial occlusion if an invariant description ofits boundary is available. Research in this area has provided a theoryfor invariant boundary descriptions based on an interplay ofdifferential, local, and global invariants. Differential invariantsrequire high-order derivatives. The use of global invariants and pointmatches on the distorting transformations enables one to reduce theorder. Trade-offs between the highest order derivatives required and thequantity of additional information constraining the distorting viewingtransformations are made explicit