Title :
Superresolution and noise filtering using moving least squares
Author :
Bose, N.K. ; Ahuja, Nilesh A.
Author_Institution :
Dept. of Electr. Eng., Pennsylvania State Univ., University Park, PA
Abstract :
An irregularly spaced sampling raster formed from a sequence of low-resolution frames is the input to an image sequence superresolution algorithm whose output is the set of image intensity values at the desired high-resolution image grid. The method of moving least squares (MLS) in polynomial space has proved to be useful in filtering the noise and approximating scattered data by minimizing a weighted mean-square error norm, but introducing blur in the process. Starting with the continuous version of the MLS, an explicit expression for the filter bandwidth is obtained as a function of the polynomial order of approximation and the standard deviation (scale) of the Gaussian weight function. A discrete implementation of the MLS is performed on images and the effect of choice of the two dependent parameters, scale and order, on noise filtering and reduction of blur introduced during the MLS process is studied
Keywords :
Gaussian processes; filtering theory; image resolution; least squares approximations; Gaussian weight function; Hermite polynomials; high-resolution image grid; image sequences; moving least squares; noise filtering; polynomial space; superresolution algorithm; Filtering; Image resolution; Image sampling; Image sequences; Least squares approximation; Least squares methods; Mean square error methods; Multilevel systems; Polynomials; Scattering; Hermite polynomials; moving least squares (MLS); superresolution;
Journal_Title :
Image Processing, IEEE Transactions on
DOI :
10.1109/TIP.2006.877406