Image SSIM

Image SSIM is a TypeScript/JavaScript library for calculating the Structural Similarity (SSIM) index between two images, suitable for both browser and server environments. This metric aims to quantify perceived image quality and similarity more effectively than traditional methods like PSNR or MSE, by focusing on structural information. Currently at version 0.2.0, this package is relatively stable for its core functionality, though its low version number suggests it may not receive frequent major feature updates or breaking changes typical of rapidly evolving libraries. Its key differentiator is providing a straightforward, cross-platform implementation of the SSIM algorithm, based on established references in the field. It is designed for developers needing a perceptual image comparison tool without heavy external dependencies. While the `npm` package `img-ssim` offers similar functionality, it uses image paths/URLs and callbacks, whereas `image-ssim` expects raw `ImageData`-like objects and returns a Promise or direct value, making `image-ssim` more suitable for in-memory image processing workflows.