Multi-Channel Deep Networks for Block-Based Image Compressive Sensing

TL;DR

This paper introduces a multichannel deep neural network for block-based image compressive sensing that leverages inter-block correlations to significantly improve reconstruction quality and speed, outperforming existing methods.

Contribution

The proposed multichannel deep network uniquely reconstructs blocks with various sampling rates in a single model, reducing blocking artifacts and enhancing image quality.

Findings

Outperforms state-of-the-art CS methods in objective metrics

Reconstructs images with fewer blocking artifacts

Achieves faster reconstruction speeds

Abstract

Incorporating deep neural networks in image compressive sensing (CS) receives intensive attentions in multimedia technology and applications recently. As deep network approaches learn the inverse mapping directly from the CS measurements, the reconstruction speed is significantly faster than the conventional CS algorithms. However, for existing network based approaches, a CS sampling procedure has to map a separate network model. This may potentially degrade the performance of image CS with block-wise sampling because of blocking artifacts, especially when multiple sampling rates are assigned to different blocks within an image. In this paper, we develop a multichannel deep network for block-based image CS by exploiting inter-block correlation with performance significantly exceeding the current state-of-the-art methods. The significant performance improvement is attributed to block-wise approximation but full image removal of blocking artifacts. Specifically, with our multichannel structure, the image blocks with a variety of sampling rates can be reconstructed in a single model. The initially reconstructed blocks are then capable of being reassembled into a full image to improve the recovered images by unrolling a hand-designed block based CS recovery algorithm. Experimental results demonstrate that the proposed method outperforms the state-of-the-art CS methods by a large margin in terms of objective metrics and subjective visual image quality. Our source codes are available at https://github.com/siwangzhou/DeepBCS.