HybridDog

// SPDX-License-Identifier: MIT
//
// This program contains an implementation of SSIM-based perceptual image
// downscaling for PNG images.
// The program can be twice as fast when compiled with -Ofast.
// The program behaviour can be adjusted with predefined preprocessor macros:
// * -DTILEABLE: Assume images wrap around at corners. This should be enabled
//   when downscaling tileable textures.
// * -DGAMMA_INCORRECT: Downscale without applying the sRGB EOTF and OETF.
//   When downscaling images with symbolic meaning, e.g. screenshots of text or