Content-Based Hyperspectral Image Compression Using a Multi-Depth Weighted Map With Dynamic Receptive Field Convolution

In content-based image compression, the importance map guides the bit allocation based on its ability to represent the importance of image contents. In this paper, we improve the representational power of importance map using Squeeze-and-Excitation (SE) block, and propose multi-depth structure to reconstruct non-important channel information at low bit rates. Furthermore, Dynamic Receptive Field convolution (DRFc) is introduced to improve the ability of normal convolution to extract edge information, so as to increase the weight of edge content in the importance map and improve the reconstruction quality of edge regions. Results indicate that our proposed method can extract an importance map with clear edges and fewer artifacts so as to provide obvious advantages for bit rate allocation in content-based image compression. Compared with typical compression methods, our proposed method can greatly improve the performance of Peak Signal-to-Noise Ratio (PSNR), structural similarity (SSIM) and spectral angle (SAM) on three public datasets, and can produce a much better visual result with sharp edges and fewer artifacts. As a result, our proposed method reduces the SAM by 42.8% compared to the recently SOTA method to achieve the same low bpp (0.25) on the KAIST dataset

Lossy-to-lossless block-based compression of hyperspectral volumetric data

An embedded, block-based, wavelet transform coding algorithm of low complexity is proposed. Three-Dimensional Set Partitioned Embedded bloCK(3D-SPECK) efficiently encodes hyperspectral volumetric image data by exploiting the dependencies in all dimensions. Integer wavelet transform is applied to enable lossy and lossless decompression from the same bit stream. We demonstrate that 3D-SPECK, a wavelet domain algorithm, like other time domain algorithms, can preserve spectral profiles well. Airborne Visible Infrared Imaging Spectrometer (AVIRIS) imagery is used to test the proposed algorithm. Results show that 3D-SPECK, in addition to being very flexible, retains all the desirable features of compared state-of-the-art algorithms and is highly competitive to 3D-SPIHT and better than JPEG2000 multi-component in compression efficiency. 1