Title :
A multiresolution nonparametric regression for spatially adaptive image de-noising
Author :
Katkovnik, Vladimir
Author_Institution :
Signal Process. Lab., Tampere Univ. of Technol., Finland
Abstract :
Recently, new efficient algorithms, based on Lepski´s approach , have been proposed for spatially adaptive varying scale de-noising. Special statistical rules are exploited in order to select the estimate with the best point-wise varying scale h from a set of test-estimates yˆh(x),h∈H. In this paper, a novel multiresolution (MR) nonparametric regression technique is developed. The adaptive algorithm consists of two steps. The first step transforms the data into noisy spectrum coefficients (MR analysis). In the second step, these noisy spectrum is filtered by the thresholding procedure and exploited for estimation (MR synthesis). This nonlinear estimate is built using the test-estimates yˆh(x) of all scales. Simulation confirms the advanced performance of the new de-noising algorithms based on the MR nonparametric regression.
Keywords :
adaptive filters; image denoising; image resolution; least squares approximations; nonlinear estimation; nonparametric statistics; regression analysis; spatial filters; spectral analysis; MR synthesis; adaptive window size; least square; multiresolution analysis; multiresolution nonparametric regression; noisy spectrum coefficient; noisy spectrum filter; nonlinear estimation; point-wise varying adaptive scale; spatially adaptive filtering; spatially adaptive image denoising; statistical rule; step transform data; test-estimate; Adaptive algorithm; Image denoising; Image resolution; Least squares methods; Noise reduction; Polynomials; Signal processing algorithms; Signal resolution; Spatial resolution; Testing; Adaptive scale; adaptive window size; moving least square; multiresolution analysis; nonparametric regression; spatially adaptive filtering;
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2004.835480