From 143959dba65c78f404a5d8984edb5ec5e507325e Mon Sep 17 00:00:00 2001 From: Lei Zhang Date: Thu, 22 Jun 2017 12:20:58 -0700 Subject: Move image_diff code into testing/image_diff/ It is not actually a sample program to demonstrate how to use PDFium APIs. It is more of a test utility program. Remove header include dependency from samples/ to core/, to set a good example. Change-Id: Idd5d567c82314bcf0e4a7bec8a3210e7d57226ee Reviewed-on: https://pdfium-review.googlesource.com/6871 Reviewed-by: dsinclair Commit-Queue: Lei Zhang --- testing/image_diff/image_diff.cpp | 336 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 336 insertions(+) create mode 100644 testing/image_diff/image_diff.cpp (limited to 'testing/image_diff/image_diff.cpp') diff --git a/testing/image_diff/image_diff.cpp b/testing/image_diff/image_diff.cpp new file mode 100644 index 0000000000..806e0c84d5 --- /dev/null +++ b/testing/image_diff/image_diff.cpp @@ -0,0 +1,336 @@ +// 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 +#include +#include +#include + +#include +#include +#include +#include +#include + +#include "core/fxcrt/fx_memory.h" +#include "testing/image_diff/image_diff_png.h" +#include "third_party/base/logging.h" +#include "third_party/base/numerics/safe_conversions.h" + +#if defined(OS_WIN) +#include +#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 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(&(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(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 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(actual.w()) * static_cast(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); +} + +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. + std::map 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); + auto 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] \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 \n" + " Compares two files on disk, outputs an image that visualizes the\n" + " difference to \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 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(&png_encoding.front()); + if (fwrite(ptr, 1, size, f) != size) + return kStatusError; + + return kStatusDifferent; +} + +int main(int argc, const char* argv[]) { + FXMEM_InitializePartitionAlloc(); + + 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; +} -- cgit v1.2.3