A Comparative Study on Lossless compression mode in WebP, Better Portable Graphics (BPG), and JPEG XL Image Compression Algorithms

On daily basis, millions of images related to the fields of medicine, astronomy, and remote sensing are generated. According to the sensitivity of the information, the generated images require storing them without any pictorial information loss. The lossless mode in image compression algorithms didn't introduce any loss to the pictorial information while compressing the image size by a ratio called the compression ratio (CR). In this study, the most recent and promising general image compression algorithms are compared side by side in terms of CR. The tested algorithms are WebP, BPG, and JPEG XL. The dataset used in this study is the TESTIMAGES archive which has been used due to its futuristic features such as high dynamic range (HDR) and high resolution as well as the availability of both natural and synthetic images. The results indicate that JPEG XL has the best CR on average compared to the other two algorithms when images with 8 bits per channel are used. Unlike the BPG and WebP, the JPEG XL offered real compression when HDR images, i.e., with 16 bits per channel, are feed for compression while the other algorithms didn't support such bit depth and generated images with 8 bits per channel.