Wang Xianghai, Cheng Lulu, Zhou Xia, Song Chuanming. Image codec research on the optimum directional selection of wavelet sub-band and compressed sensing[J]. Journal of Image and Graphics, 2013, 18(12): 1551-1558. DOI: 10.11834/jig.20131201.
For the problem of large decoding errors generated by the image compression based on Bayesian compressed sensing with local optimization
a new codec uniting the optimal directional selection of wavelet sub-bands with Bayesian compressed sensing is proposed
which reduces the error of the decoded images and increases the accuracy of the codec. According to the correlation differences between the low-frequency and the high-frequency sub-bands
we use a respective codec for each of them. Low-frequency coefficients contain the images' main information. With the purpose of avoiding local optimization
we apply the correlation of the low-frequency sub-band
introducing the optimal direction selection codec to the low-frequency coefficients
and combining Bayesian compressed sensing based on the wavelet transform to deal with high-frequency coefficients containing details of images. The experimental results show that in the case without increasing the bit rate
the decoded images using the proposed method have good subjective quality
and the PSNR and SSIM of images are improved to some extent.