Xin Gangtao, Fan Pingyi
Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Beijing National Research Center for Information Science and Technology (BNRist), Beijing 100084, China.
Entropy (Basel). 2021 Dec 14;23(12):1680. doi: 10.3390/e23121680.
Soft compression is a lossless image compression method that is committed to eliminating coding redundancy and spatial redundancy simultaneously. To do so, it adopts shapes to encode an image. In this paper, we propose a compressible indicator function with regard to images, which gives a threshold of the average number of bits required to represent a location and can be used for illustrating the working principle. We investigate and analyze soft compression for binary image, gray image and multi-component image with specific algorithms and compressible indicator value. In terms of compression ratio, the soft compression algorithm outperforms the popular classical standards PNG and JPEG2000 in lossless image compression. It is expected that the bandwidth and storage space needed when transmitting and storing the same kind of images (such as medical images) can be greatly reduced with applying soft compression.
软压缩是一种无损图像压缩方法，致力于同时消除编码冗余和空间冗余。为此，它采用形状对图像进行编码。在本文中，我们提出了一种关于图像的可压缩指标函数，该函数给出了表示一个位置所需的平均比特数的阈值，可用于说明工作原理。我们使用特定算法和可压缩指标值对二值图像、灰度图像和多分量图像的软压缩进行了研究和分析。在压缩比方面，软压缩算法在无损图像压缩方面优于流行的经典标准PNG和JPEG2000。预计应用软压缩可以大大减少传输和存储同类型图像（如医学图像）时所需的带宽和存储空间。
