Study On The Image Coding And Reconstruction Algorithm Based On Compressed Sensing

Compressed Sensing (CS), which can use the frequency that far less than the required sampling frequency of the Nyquist Sampling Theorem to sample the signal and accurately reconstruct the signal, is a theory developed in recent years and has attracted much public attention in the area of image.On the basis of reading a lot of reference material, deep analysis and research on the algorithm of image coding and reconstruction based on compressive sensing are made in this paper. This paper proposes an adaptive image coding algorithm based on compressive sensing and an image blocking reconstruction algorithm based on the total variation minimization, moreover, according to the interframe redundancy of image sequence, the paper proposes an adaptive coding algorithm for image sequence.When the image is compressed and reconstructed with compressive sensing theory at the same sampling rate, the low sampling rate can’t ensure that every block in the image obtains the higher reconstruction quality and the high sampling rate usually leads to the resource waste because of the different sparseness degree for each block in the image. In order to solve the above problem, an image adaptive coding algorithm based on compressive sensing is proposed in this paper. The sparseness degree in DCT domain for each block in the image is estimated firstly, then the adaptive compression is applied to each block according to the estimated results, thus a higher reconstruction quality is acquired for the image at a lower sampling rate.While using compressed sensing theory to process image reconstruction, the method based on the block may improve the speed of the reconstruction obviously, but this will bring a strong blocking effects., an image block reconstruction algorithm based on TV norm is proposed, which improves the gradient calculation method based on the entire image, and makes full use of the boundary pixel information that has been reconstructed, thus the image blocking effects are eliminated effectively.When encoding the image sequences, there is much redundant information among the image sequences. This paper proposed an adaptive coding algorithm according to the residual between the sequence frames. This algorithm is especially useful for those slow motion sequences, which can not only ensure the quality of the reconstructions of the sequences, but also can reduce the sampling data and improve the compression ratio at maximum, is especially useful for those slow motion sequences.