Image MSE Image mean square error (MSE). In TypeScript/JavaScript. For browser/server. Features Luminosity calculation Alpha channel multiplier Four channel variants: Grey = 1, GreyAlpha = 2, RGB = 3, RGBAlpha = 4 Calculates peak signal-to-noise ratio (PSNR) too Documentation http://darosh.github.io/image-mse-js/doc/