This tool computes (dis)similarity between two or more PNG images using an algorithm approximating human vision. Comparison is done in L*a*b* color space (D65 white point, sRGB gamma) using a multi-scale variant of the SSIM algorithm. Features: - Improved algorithm - Compares at multiple weighed resolutions, and scaling is done in linear-light RGB. It's sensitive to distortions of various sizes and blends colors correctly to detect e.g. chroma subsampling errors. - Uses L*a*b* color space for the SSIM algorithm. It measures brightness and color much better than metrics from average of RGB channels. - Supports alpha channel. - Supports images with color profiles. - Takes advantage of multi-core CPUs. - Can be used as a library in C, Rust, and WASM. - No OpenCV or MATLAB needed. WWW: https://kornel.ski/dssim