Chan, Wai LamChoi, HyeokhoBaraniuk, Richard G.2007-10-312007-10-312005-08-012005-08-01W. L. Chan, H. Choi and R. G. Baraniuk, "Coherent Image Processing using Quaternion Wavelets," 2005.https://hdl.handle.net/1911/19776Conference paperWe develop a quaternion wavelet transform (QWT) as a new multiscale analysis tool for geometric image features. The QWT is a near shift-invariant, tight frame representation whose coefficients sport a magnitude and three phase values, two of which are directly proportional to local image shifts. The QWT can be efficiently computed using a dual-tree filter bank and is based on a 2-D Hilbert transform. We demonstrate how the QWT's magnitude and phase can be used to accurately analyze local geometric structure in images. We also develop a multiscale flow/motion estimation algorithm that computes a disparity flow map between two images with respect to local object motion.engWaveletsquaternionsedgesimage registrationdisparityImage Processing and Pattern analysisConference paperWaveletsquaternionsedgesimage registrationdisparity