eiryou/rqshc-image-compressor

RQSHC V64I is a research and evaluation tool for Windows that compresses images using a custom format the author invented, called RQI. Rather than wrapping an existing compression library, the author built the core compression and decompression logic from scratch in native C++17, with some performance critical parts written in x64 assembly and using AVX2 processor optimizations. The goal was to have a real environment for studying the tradeoffs between how small a compressed file becomes, how close the restored image looks to the original, and how fast the whole process runs, rather than just calling someone else's codec. All processing happens on the user's own computer. Images are not sent to any external cloud service to be compressed. The project recently added a web based version built with WebAssembly so people can try compression quickly in a browser, and images still are not uploaded to a server in that version, though the web version runs a little slower and compresses slightly less than the native Windows program. Right now the tool accepts PNG, PPM, and Windows Bitmap files as input, formats like JPEG, WebP, GIF, and TIFF are not supported and need to be converted first. The output is the custom RQI format, which cannot be opened by normal image viewers, so the project bundles its own viewer program that can open RQI files, zoom and scroll around them, and export them back to PNG. A separate program handles the actual compression step. In benchmark tests included in the README, compressing a set of PNG images took roughly 65 to 630 milliseconds depending on the test run, shrank file size by around 33 to 35 percent on average, and kept a measured similarity score to the original very close to perfect. The author is upfront that results vary by image and are not guaranteed for every file, and that the compression core itself is currently closed source. Because the released program is not code signed, Windows may show an unrecognized publisher warning the first time it runs, which the author says is expected for a new unsigned tool rather than a sign of malware. Free use is allowed for personal, educational, and research purposes, but building the compression core into a commercial product, offering it as a paid service, or making a compatible product requires contacting the author for separate permission.