Noise reduction for image sequences using an oriented pyramid thresholding technique
Peter M.B. van Roosmalen, Stefan J. P. Westen, Reginald L. Lagendijk, Jan Biemond · 2002
Denoising images by means of thresholding transform coefficients has become popular. The discrete wavelet transform (DWT) seems to be very useful in this context. We propose a method for achieving a spatio-temporal decomposition of image sequences by combining the spacial Simoncelli (1992) pyramid with, in a temporal direction, wavelets. The directionally sensitive filter banks of the Simoncelli pyramid lead to better separation of signal and noise compared to a separable DWT. Including motion compensated temporal information further improves this separation. The directional sensitive filters also make it possible to locally estimate the amount of noise and the orientation of image structures. This information can be used to control the thresholding operation.