godot/thirdparty/basis_universal/encoder/basisu_ssim.cpp

// basisu_ssim.cpp
// Copyright (C) 2019 Binomial LLC. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "basisu_ssim.h"

#ifndef M_PI
#define M_PI …
#endif

namespace basisu
{
	float gauss(int x, int y, float sigma_sqr)
	{ … }
		
	// size_x/y should be odd
	void compute_gaussian_kernel(float *pDst, int size_x, int size_y, float sigma_sqr, uint32_t flags)
	{ … }

	void gaussian_filter(imagef &dst, const imagef &orig_img, uint32_t odd_filter_width, float sigma_sqr, bool wrapping, uint32_t width_divisor, uint32_t height_divisor)
	{ … }

	void pow_image(const imagef &src, imagef &dst, const vec4F &power)
	{ … }

	void mul_image(const imagef &src, imagef &dst, const vec4F &mul)
	{ … }

	void scale_image(const imagef &src, imagef &dst, const vec4F &scale, const vec4F &shift)
	{ … }

	void add_weighted_image(const imagef &src1, const vec4F &alpha, const imagef &src2, const vec4F &beta, const vec4F &gamma, imagef &dst)
	{ … }

	void add_image(const imagef &src1, const imagef &src2, imagef &dst)
	{ … }

	void adds_image(const imagef &src, const vec4F &value, imagef &dst)
	{ … }

	void mul_image(const imagef &src1, const imagef &src2, imagef &dst, const vec4F &scale)
	{ … }

	void div_image(const imagef &src1, const imagef &src2, imagef &dst, const vec4F &scale)
	{ … }

	vec4F avg_image(const imagef &src)
	{ … }
		
	// Reference: https://ece.uwaterloo.ca/~z70wang/research/ssim/index.html
	vec4F compute_ssim(const imagef &a, const imagef &b)
	{ … }

	vec4F compute_ssim(const image &a, const image &b, bool luma, bool luma_601)
	{ … }

} // namespace basisu