Patent ID: 8587703
Filing Date: 2013-11-19
Classification: H04N

Abstract:
1. A method of restoring an image, comprising: receiving a plurality of observed signals from a plurality of channels of the image, wherein the plurality of observed signals comprise a first observed signal and a second observed signal, and wherein the first and second observed signals are degradations of an original signal in a window of the image; performing lens shading correction on the plurality of observed signals; calculating one or more estimates of a signal offset of the first observed signal and the second observed signal, wherein the one or more estimates of the signal offset are measures of an imbalance between channels of the plurality of channels corresponding to the first observed signal and the second observed signal; and generating at least one recovered signal based at least in part on the one or more estimates of the signal offset, said generating including: calculating a cross-channel recovery kernel of a first offset removed signal and a second offset-removed signal; removing the one or more estimates of the signal offset from the first observed signal and the second observed signal to generate the first offset-removed signal and the second offset-removed signal; and applying the cross-channel recovery kernel to the first and the second offset-removed signals to generate the at least one recovered signal, wherein (i) said calculating the cross-channel recovery kernel comprises: receiving information associated with at least one point spread function (PSF), the at least one PSF comprising blurring information of the first and the second observed signals; receiving information associated with one or more weights, the one or more weights are associated with one or more parameterizations of restoration kernels; determining a cross-channel signal to noise ratio (SNR) estimate in the window, the cross-channel SNR estimate being a function of an estimated cross-channel variance of the original signal and an estimated variance of cross-channel sensor noise; and generating the cross-channel recovery kernel based on one or more of the information associated with the at least one PSF, the information associated with the one or more weights, and the cross-channel SNR estimate, and (ii) said determining the cross-channel SNR estimate comprises: receiving at least one sensor state signal; determining the estimated variance of the cross-channel sensor noise based on the at least one sensor state signal and at least one statistic associated with the first offset-removed signal and the second offset-removed signal; determining the estimated cross-channel variance of the original signal based on one or more of (a) the information associated with the at least one PSF, (b) the estimated variance of the cross-channel sensor noise, and (c) the at least one statistic associated with the first offset-removed signal and the second offset-removed signal; and generating the cross-channel SNR estimate, wherein the cross-channel SNR estimate is a ratio between the estimated cross-channel variance of the original signal and the estimated variance of the cross-channel sensor noise.