| // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
| // 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 <assert.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include <algorithm> |
| #include <iostream> |
| #include <map> |
| #include <string> |
| #include <vector> |
| |
| #include "image_diff_png.h" |
| #include "third_party/base/logging.h" |
| #include "third_party/base/numerics/safe_conversions.h" |
| |
| #if defined(OS_WIN) |
| #include <windows.h> |
| #endif |
| |
| // Return codes used by this utility. |
| static const int kStatusSame = 0; |
| static const int kStatusDifferent = 1; |
| static const int kStatusError = 2; |
| |
| // Color codes. |
| static const uint32_t RGBA_RED = 0x000000ff; |
| static const uint32_t RGBA_ALPHA = 0xff000000; |
| |
| class Image { |
| public: |
| Image() : w_(0), h_(0) { |
| } |
| |
| Image(const Image& image) |
| : w_(image.w_), |
| h_(image.h_), |
| data_(image.data_) { |
| } |
| |
| bool has_image() const { |
| return w_ > 0 && h_ > 0; |
| } |
| |
| int w() const { |
| return w_; |
| } |
| |
| int h() const { |
| return h_; |
| } |
| |
| const unsigned char* data() const { |
| return &data_.front(); |
| } |
| |
| // Creates the image from the given filename on disk, and returns true on |
| // success. |
| bool CreateFromFilename(const std::string& path) { |
| FILE* f = fopen(path.c_str(), "rb"); |
| if (!f) |
| return false; |
| |
| std::vector<unsigned char> compressed; |
| const size_t kBufSize = 1024; |
| unsigned char buf[kBufSize]; |
| size_t num_read = 0; |
| while ((num_read = fread(buf, 1, kBufSize, f)) > 0) { |
| compressed.insert(compressed.end(), buf, buf + num_read); |
| } |
| |
| fclose(f); |
| |
| if (!image_diff_png::DecodePNG(compressed.data(), compressed.size(), &data_, |
| &w_, &h_)) { |
| Clear(); |
| return false; |
| } |
| return true; |
| } |
| |
| void Clear() { |
| w_ = h_ = 0; |
| data_.clear(); |
| } |
| |
| // Returns the RGBA value of the pixel at the given location |
| uint32_t pixel_at(int x, int y) const { |
| if (!pixel_in_bounds(x, y)) |
| return 0; |
| return *reinterpret_cast<const uint32_t*>(&(data_[pixel_address(x, y)])); |
| } |
| |
| void set_pixel_at(int x, int y, uint32_t color) { |
| if (!pixel_in_bounds(x, y)) |
| return; |
| |
| void* addr = &data_[pixel_address(x, y)]; |
| *reinterpret_cast<uint32_t*>(addr) = color; |
| } |
| |
| private: |
| bool pixel_in_bounds(int x, int y) const { |
| return x >= 0 && x < w_ && y >= 0 && y < h_; |
| } |
| |
| size_t pixel_address(int x, int y) const { return (y * w_ + x) * 4; } |
| |
| // Pixel dimensions of the image. |
| int w_; |
| int h_; |
| |
| std::vector<unsigned char> data_; |
| }; |
| |
| float CalculateDifferencePercentage(const Image& actual, int pixels_different) { |
| // Like the WebKit ImageDiff tool, we define percentage different in terms |
| // of the size of the 'actual' bitmap. |
| float total_pixels = |
| static_cast<float>(actual.w()) * static_cast<float>(actual.h()); |
| if (total_pixels == 0) { |
| // When the bitmap is empty, they are 100% different. |
| return 100.0f; |
| } |
| return 100.0f * pixels_different / total_pixels; |
| } |
| |
| void CountImageSizeMismatchAsPixelDifference(const Image& baseline, |
| const Image& actual, |
| int* pixels_different) { |
| int w = std::min(baseline.w(), actual.w()); |
| int h = std::min(baseline.h(), actual.h()); |
| |
| // Count pixels that are a difference in size as also being different. |
| int max_w = std::max(baseline.w(), actual.w()); |
| int max_h = std::max(baseline.h(), actual.h()); |
| // These pixels are off the right side, not including the lower right corner. |
| *pixels_different += (max_w - w) * h; |
| // These pixels are along the bottom, including the lower right corner. |
| *pixels_different += (max_h - h) * max_w; |
| } |
| |
| float PercentageDifferent(const Image& baseline, const Image& actual) { |
| int w = std::min(baseline.w(), actual.w()); |
| int h = std::min(baseline.h(), actual.h()); |
| |
| // Compute pixels different in the overlap. |
| int pixels_different = 0; |
| for (int y = 0; y < h; ++y) { |
| for (int x = 0; x < w; ++x) { |
| if (baseline.pixel_at(x, y) != actual.pixel_at(x, y)) |
| ++pixels_different; |
| } |
| } |
| |
| CountImageSizeMismatchAsPixelDifference(baseline, actual, &pixels_different); |
| return CalculateDifferencePercentage(actual, pixels_different); |
| } |
| |
| // FIXME: Replace with unordered_map when available. |
| typedef std::map<uint32_t, int32_t> RgbaToCountMap; |
| |
| float HistogramPercentageDifferent(const Image& baseline, const Image& actual) { |
| // TODO(johnme): Consider using a joint histogram instead, as described in |
| // "Comparing Images Using Joint Histograms" by Pass & Zabih |
| // http://www.cs.cornell.edu/~rdz/papers/pz-jms99.pdf |
| |
| int w = std::min(baseline.w(), actual.w()); |
| int h = std::min(baseline.h(), actual.h()); |
| |
| // Count occurences of each RGBA pixel value of baseline in the overlap. |
| RgbaToCountMap baseline_histogram; |
| for (int y = 0; y < h; ++y) { |
| for (int x = 0; x < w; ++x) { |
| // hash_map operator[] inserts a 0 (default constructor) if key not found. |
| ++baseline_histogram[baseline.pixel_at(x, y)]; |
| } |
| } |
| |
| // Compute pixels different in the histogram of the overlap. |
| int pixels_different = 0; |
| for (int y = 0; y < h; ++y) { |
| for (int x = 0; x < w; ++x) { |
| uint32_t actual_rgba = actual.pixel_at(x, y); |
| RgbaToCountMap::iterator it = baseline_histogram.find(actual_rgba); |
| if (it != baseline_histogram.end() && it->second > 0) |
| --it->second; |
| else |
| ++pixels_different; |
| } |
| } |
| |
| CountImageSizeMismatchAsPixelDifference(baseline, actual, &pixels_different); |
| return CalculateDifferencePercentage(actual, pixels_different); |
| } |
| |
| void PrintHelp() { |
| fprintf(stderr, |
| "Usage:\n" |
| " image_diff [--histogram] <compare file> <reference file>\n" |
| " Compares two files on disk, returning 0 when they are the same;\n" |
| " passing \"--histogram\" additionally calculates a diff of the\n" |
| " RGBA value histograms (which is resistant to shifts in layout)\n" |
| " image_diff --diff <compare file> <reference file> <output file>\n" |
| " Compares two files on disk, outputs an image that visualizes the\n" |
| " difference to <output file>\n"); |
| } |
| |
| int CompareImages(const std::string& file1, |
| const std::string& file2, |
| bool compare_histograms) { |
| Image actual_image; |
| Image baseline_image; |
| |
| if (!actual_image.CreateFromFilename(file1)) { |
| fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file1.c_str()); |
| return kStatusError; |
| } |
| if (!baseline_image.CreateFromFilename(file2)) { |
| fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file2.c_str()); |
| return kStatusError; |
| } |
| |
| if (compare_histograms) { |
| float percent = HistogramPercentageDifferent(actual_image, baseline_image); |
| const char* passed = percent > 0.0 ? "failed" : "passed"; |
| printf("histogram diff: %01.2f%% %s\n", percent, passed); |
| } |
| |
| const char* const diff_name = compare_histograms ? "exact diff" : "diff"; |
| float percent = PercentageDifferent(actual_image, baseline_image); |
| const char* const passed = percent > 0.0 ? "failed" : "passed"; |
| printf("%s: %01.2f%% %s\n", diff_name, percent, passed); |
| |
| if (percent > 0.0) { |
| // failure: The WebKit version also writes the difference image to |
| // stdout, which seems excessive for our needs. |
| return kStatusDifferent; |
| } |
| // success |
| return kStatusSame; |
| } |
| |
| bool CreateImageDiff(const Image& image1, const Image& image2, Image* out) { |
| int w = std::min(image1.w(), image2.w()); |
| int h = std::min(image1.h(), image2.h()); |
| *out = Image(image1); |
| bool same = (image1.w() == image2.w()) && (image1.h() == image2.h()); |
| |
| // TODO(estade): do something with the extra pixels if the image sizes |
| // are different. |
| for (int y = 0; y < h; ++y) { |
| for (int x = 0; x < w; ++x) { |
| uint32_t base_pixel = image1.pixel_at(x, y); |
| if (base_pixel != image2.pixel_at(x, y)) { |
| // Set differing pixels red. |
| out->set_pixel_at(x, y, RGBA_RED | RGBA_ALPHA); |
| same = false; |
| } else { |
| // Set same pixels as faded. |
| uint32_t alpha = base_pixel & RGBA_ALPHA; |
| uint32_t new_pixel = base_pixel - ((alpha / 2) & RGBA_ALPHA); |
| out->set_pixel_at(x, y, new_pixel); |
| } |
| } |
| } |
| |
| return same; |
| } |
| |
| int DiffImages(const std::string& file1, |
| const std::string& file2, |
| const std::string& out_file) { |
| Image actual_image; |
| Image baseline_image; |
| |
| if (!actual_image.CreateFromFilename(file1)) { |
| fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file1.c_str()); |
| return kStatusError; |
| } |
| if (!baseline_image.CreateFromFilename(file2)) { |
| fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file2.c_str()); |
| return kStatusError; |
| } |
| |
| Image diff_image; |
| bool same = CreateImageDiff(baseline_image, actual_image, &diff_image); |
| if (same) |
| return kStatusSame; |
| |
| std::vector<unsigned char> png_encoding; |
| image_diff_png::EncodeRGBAPNG( |
| diff_image.data(), diff_image.w(), diff_image.h(), |
| diff_image.w() * 4, &png_encoding); |
| |
| FILE* f = fopen(out_file.c_str(), "wb"); |
| if (!f) |
| return kStatusError; |
| |
| size_t size = png_encoding.size(); |
| char* ptr = reinterpret_cast<char*>(&png_encoding.front()); |
| if (fwrite(ptr, 1, size, f) != size) |
| return kStatusError; |
| |
| return kStatusDifferent; |
| } |
| |
| int main(int argc, const char* argv[]) { |
| bool histograms = false; |
| bool produce_diff_image = false; |
| std::string filename1; |
| std::string filename2; |
| std::string diff_filename; |
| |
| int i; |
| for (i = 1; i < argc; ++i) { |
| const char* arg = argv[i]; |
| if (strstr(arg, "--") != arg) |
| break; |
| if (strcmp(arg, "--histogram") == 0) { |
| histograms = true; |
| } else if (strcmp(arg, "--diff") == 0) { |
| produce_diff_image = true; |
| } |
| } |
| if (i < argc) |
| filename1 = argv[i++]; |
| if (i < argc) |
| filename2 = argv[i++]; |
| if (i < argc) |
| diff_filename = argv[i++]; |
| |
| if (produce_diff_image) { |
| if (!diff_filename.empty()) { |
| return DiffImages(filename1, filename2, diff_filename); |
| } |
| } else if (!filename2.empty()) { |
| return CompareImages(filename1, filename2, histograms); |
| } |
| |
| PrintHelp(); |
| return kStatusError; |
| } |