Ji Jian, Li Xiao, Xu Shuangxing. Image reconstruction algorithm based on the curvelet gaussian scale mixture model[J]. Journal of Image and Graphics, 2013, 18(10): 1247-1254.DOI: 10.11834/jig.20131004.
Compressed sensing theory samples and compresses the signals at the same time and uses the prior knowledge that signals can be represented sparsely in the transform domain to reconstruct the original signals with less measurements than Shannon-Nyquist theory. Recently
two-step Iterative Shrinkage/Threshold algorithm has been applied to compressed reconstruction as an optimization method to solve inverse problems for its tight connection with multi-scale geometry analysis
fewer parameters and simplicity. Using the hard and soft threshold operators in the time domain makes it hard to obtain sparse representation for two dimensional images. Consequently
the reconstruction precision of the algorithm is low. Based on the TwIST algorithm
an adaptive two-step Iterative Shrinkage/Threshold algorithm is presented. It makes use of the information obtained from current estimated values to calculate the step parameters and ensure the estimate value moving towards the optimum solution to improve its reconstruction precision. Regarding the poor ability to represent images sparsely
we use the Gaussian scale mixture model to model the curvelet neighborhood coefficients and enhance the ability of image sparse representation with the shift-invariance and directional-selectivity of the curvelet transform. Finally
the method is applied to image compression reconstruction and the experimental results show that it is better than both
the wavelet Gaussian scale mixture models and the curvelet hard threshold reconstruction methods in terms of subjective visual and peak signal noise ratio.