chromium/third_party/pdfium/testing/image_diff/image_diff.cpp

// Copyright 2011 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This file input format is based loosely on
// Tools/DumpRenderTree/ImageDiff.m

// The exact format of this tool's output to stdout is important, to match
// what the run-webkit-tests script expects.

#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include <algorithm>
#include <cmath>
#include <map>
#include <string>
#include <vector>

#include "core/fxcrt/fx_memory.h"
#include "core/fxcrt/numerics/safe_conversions.h"
#include "testing/image_diff/image_diff_png.h"
#include "testing/utils/path_service.h"

#if BUILDFLAG(IS_WIN)
#include <windows.h>
#endif

// Return codes used by this utility.
constexpr int kStatusSame = …;
constexpr int kStatusDifferent = …;
constexpr int kStatusError = …;

// Color codes.
constexpr uint32_t RGBA_RED = …;
constexpr uint32_t RGBA_ALPHA = …;

class Image { … };

float CalculateDifferencePercentage(const Image& actual, int pixels_different) { … }

void CountImageSizeMismatchAsPixelDifference(const Image& baseline,
                                             const Image& actual,
                                             int* pixels_different) { … }

struct UnpackedPixel { … };

uint8_t ChannelDelta(uint8_t baseline_channel, uint8_t actual_channel) { … }

uint8_t MaxPixelPerChannelDelta(const UnpackedPixel& baseline_pixel,
                                const UnpackedPixel& actual_pixel) { … }

float PercentageDifferent(const Image& baseline,
                          const Image& actual,
                          uint8_t max_pixel_per_channel_delta) { … }

float HistogramPercentageDifferent(const Image& baseline, const Image& actual) { … }

void PrintHelp(const std::string& binary_name) { … }

int CompareImages(const std::string& binary_name,
                  const std::string& file1,
                  const std::string& file2,
                  bool compare_histograms,
                  bool reverse_byte_order,
                  uint8_t max_pixel_per_channel_delta) { … }

bool CreateImageDiff(const Image& image1, const Image& image2, Image* out) { … }

bool SubtractImages(const Image& image1, const Image& image2, Image* out) { … }

int DiffImages(const std::string& binary_name,
               const std::string& file1,
               const std::string& file2,
               const std::string& out_file,
               bool do_subtraction,
               bool reverse_byte_order) { … }

int main(int argc, const char* argv[]) { … }