Block-Based Compressive Sensing Coding of Natural Images by Local Structural Measurement Matrix
Gaussian random matrix (GRM) has been widely used to generate linear measurements in compressive sensing (CS) of natural images. However, in practice, there actually exist two problems with GRM. One is that GRM is non-sparse and complicated, leading to high computational complexity and high difficulty in hardware implementation. The other is that regardless of the characteristics of signal the measurements generated by GRM are also random, which results in low efficiency of compression coding. In this paper, we design a novel local structural measurement matrix (LSMM) for block-based CS coding of natural images by utilizing the local smooth property of images. The proposed LSMM has two main advantages. First, LSMM is a highly sparse matrix, which can be easily implemented in hardware, and its reconstruction performance is even superior to GRM at low CS sampling sub rate. Second, the adjacent measurement elements generated by LSMM have high correlation, which can be exploited to greatly improve the coding efficiency. Furthermore, this paper presents a new framework with LSMM for block-based CS coding of natural images, including measurement generating, measurement coding and CS reconstruction. Experimental results show that the proposed framework with LSMM for block-based CS coding of natural images greatly enhances the existing CS coding performance when compared with other state-of-the-art image CS coding schemes.