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Diffstat (limited to 'samples/image_diff_png.cc')
| -rw-r--r-- | samples/image_diff_png.cc | 644 |
1 files changed, 0 insertions, 644 deletions
diff --git a/samples/image_diff_png.cc b/samples/image_diff_png.cc deleted file mode 100644 index 3d12b7e948..0000000000 --- a/samples/image_diff_png.cc +++ /dev/null @@ -1,644 +0,0 @@ -// Copyright 2013 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 is a duplicate of chromium's src/tools/imagediff/image_diff_png.cc -// that has been modified to build in a pdfium environment, which itself -// was duplicated as follows: - -// This is a duplicate of ui/gfx/codec/png_codec.cc, after removing code related -// to Skia, that we can use when running layout tests with minimal dependencies. - -#include "samples/image_diff_png.h" - -#include <stdlib.h> -#include <string.h> - -#include <string> - -#include "third_party/base/logging.h" -#include "third_party/libpng16/png.h" -#include "third_party/zlib/zlib.h" - -namespace image_diff_png { - -namespace { - -enum ColorFormat { - // 3 bytes per pixel (packed), in RGB order regardless of endianness. - // This is the native JPEG format. - FORMAT_RGB, - - // 4 bytes per pixel, in RGBA order in memory regardless of endianness. - FORMAT_RGBA, - - // 4 bytes per pixel, in BGRA order in memory regardless of endianness. - // This is the default Windows DIB order. - FORMAT_BGRA, -}; - -// Represents a comment in the tEXt ancillary chunk of the png. -struct Comment { - std::string key; - std::string text; -}; - -// Converts BGRA->RGBA and RGBA->BGRA. -void ConvertBetweenBGRAandRGBA(const unsigned char* input, int pixel_width, - unsigned char* output, bool* is_opaque) { - for (int x = 0; x < pixel_width; x++) { - const unsigned char* pixel_in = &input[x * 4]; - unsigned char* pixel_out = &output[x * 4]; - pixel_out[0] = pixel_in[2]; - pixel_out[1] = pixel_in[1]; - pixel_out[2] = pixel_in[0]; - pixel_out[3] = pixel_in[3]; - } -} - -void ConvertRGBAtoRGB(const unsigned char* rgba, int pixel_width, - unsigned char* rgb, bool* is_opaque) { - for (int x = 0; x < pixel_width; x++) { - const unsigned char* pixel_in = &rgba[x * 4]; - unsigned char* pixel_out = &rgb[x * 3]; - pixel_out[0] = pixel_in[0]; - pixel_out[1] = pixel_in[1]; - pixel_out[2] = pixel_in[2]; - } -} - -} // namespace - -// Decoder -// -// This code is based on WebKit libpng interface (PNGImageDecoder), which is -// in turn based on the Mozilla png decoder. - -namespace { - -// Gamma constants: We assume we're on Windows which uses a gamma of 2.2. -const double kMaxGamma = 21474.83; // Maximum gamma accepted by png library. -const double kDefaultGamma = 2.2; -const double kInverseGamma = 1.0 / kDefaultGamma; - -class PngDecoderState { - public: - // Output is a vector<unsigned char>. - PngDecoderState(ColorFormat ofmt, std::vector<unsigned char>* o) - : output_format(ofmt), - output_channels(0), - is_opaque(true), - output(o), - row_converter(NULL), - width(0), - height(0), - done(false) { - } - - ColorFormat output_format; - int output_channels; - - // Used during the reading of an SkBitmap. Defaults to true until we see a - // pixel with anything other than an alpha of 255. - bool is_opaque; - - // An intermediary buffer for decode output. - std::vector<unsigned char>* output; - - // Called to convert a row from the library to the correct output format. - // When NULL, no conversion is necessary. - void (*row_converter)(const unsigned char* in, int w, unsigned char* out, - bool* is_opaque); - - // Size of the image, set in the info callback. - int width; - int height; - - // Set to true when we've found the end of the data. - bool done; -}; - -void ConvertRGBtoRGBA(const unsigned char* rgb, int pixel_width, - unsigned char* rgba, bool* is_opaque) { - for (int x = 0; x < pixel_width; x++) { - const unsigned char* pixel_in = &rgb[x * 3]; - unsigned char* pixel_out = &rgba[x * 4]; - pixel_out[0] = pixel_in[0]; - pixel_out[1] = pixel_in[1]; - pixel_out[2] = pixel_in[2]; - pixel_out[3] = 0xff; - } -} - -void ConvertRGBtoBGRA(const unsigned char* rgb, int pixel_width, - unsigned char* bgra, bool* is_opaque) { - for (int x = 0; x < pixel_width; x++) { - const unsigned char* pixel_in = &rgb[x * 3]; - unsigned char* pixel_out = &bgra[x * 4]; - pixel_out[0] = pixel_in[2]; - pixel_out[1] = pixel_in[1]; - pixel_out[2] = pixel_in[0]; - pixel_out[3] = 0xff; - } -} - -// Called when the png header has been read. This code is based on the WebKit -// PNGImageDecoder -void DecodeInfoCallback(png_struct* png_ptr, png_info* info_ptr) { - PngDecoderState* state = static_cast<PngDecoderState*>( - png_get_progressive_ptr(png_ptr)); - - int bit_depth, color_type, interlace_type, compression_type; - int filter_type, channels; - png_uint_32 w, h; - png_get_IHDR(png_ptr, info_ptr, &w, &h, &bit_depth, &color_type, - &interlace_type, &compression_type, &filter_type); - - // Bounds check. When the image is unreasonably big, we'll error out and - // end up back at the setjmp call when we set up decoding. "Unreasonably big" - // means "big enough that w * h * 32bpp might overflow an int"; we choose this - // threshold to match WebKit and because a number of places in code assume - // that an image's size (in bytes) fits in a (signed) int. - unsigned long long total_size = - static_cast<unsigned long long>(w) * static_cast<unsigned long long>(h); - if (total_size > ((1 << 29) - 1)) - longjmp(png_jmpbuf(png_ptr), 1); - state->width = static_cast<int>(w); - state->height = static_cast<int>(h); - - // Expand to ensure we use 24-bit for RGB and 32-bit for RGBA. - if (color_type == PNG_COLOR_TYPE_PALETTE || - (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)) - png_set_expand(png_ptr); - - // Transparency for paletted images. - if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) - png_set_expand(png_ptr); - - // Convert 16-bit to 8-bit. - if (bit_depth == 16) - png_set_strip_16(png_ptr); - - // Expand grayscale to RGB. - if (color_type == PNG_COLOR_TYPE_GRAY || - color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - png_set_gray_to_rgb(png_ptr); - - // Deal with gamma and keep it under our control. - double gamma; - if (png_get_gAMA(png_ptr, info_ptr, &gamma)) { - if (gamma <= 0.0 || gamma > kMaxGamma) { - gamma = kInverseGamma; - png_set_gAMA(png_ptr, info_ptr, gamma); - } - png_set_gamma(png_ptr, kDefaultGamma, gamma); - } else { - png_set_gamma(png_ptr, kDefaultGamma, kInverseGamma); - } - - // Tell libpng to send us rows for interlaced pngs. - if (interlace_type == PNG_INTERLACE_ADAM7) - png_set_interlace_handling(png_ptr); - - // Update our info now - png_read_update_info(png_ptr, info_ptr); - channels = png_get_channels(png_ptr, info_ptr); - - // Pick our row format converter necessary for this data. - if (channels == 3) { - switch (state->output_format) { - case FORMAT_RGB: - state->row_converter = NULL; // no conversion necessary - state->output_channels = 3; - break; - case FORMAT_RGBA: - state->row_converter = &ConvertRGBtoRGBA; - state->output_channels = 4; - break; - case FORMAT_BGRA: - state->row_converter = &ConvertRGBtoBGRA; - state->output_channels = 4; - break; - default: - NOTREACHED(); - break; - } - } else if (channels == 4) { - switch (state->output_format) { - case FORMAT_RGB: - state->row_converter = &ConvertRGBAtoRGB; - state->output_channels = 3; - break; - case FORMAT_RGBA: - state->row_converter = NULL; // no conversion necessary - state->output_channels = 4; - break; - case FORMAT_BGRA: - state->row_converter = &ConvertBetweenBGRAandRGBA; - state->output_channels = 4; - break; - default: - NOTREACHED(); - break; - } - } else { - NOTREACHED(); - longjmp(png_jmpbuf(png_ptr), 1); - } - - state->output->resize( - state->width * state->output_channels * state->height); -} - -void DecodeRowCallback(png_struct* png_ptr, png_byte* new_row, - png_uint_32 row_num, int pass) { - PngDecoderState* state = static_cast<PngDecoderState*>( - png_get_progressive_ptr(png_ptr)); - - if (static_cast<int>(row_num) > state->height) { - NOTREACHED(); - return; - } - - unsigned char* base = NULL; - base = &state->output->front(); - - unsigned char* dest = &base[state->width * state->output_channels * row_num]; - if (state->row_converter) - state->row_converter(new_row, state->width, dest, &state->is_opaque); - else - memcpy(dest, new_row, state->width * state->output_channels); -} - -void DecodeEndCallback(png_struct* png_ptr, png_info* info) { - PngDecoderState* state = static_cast<PngDecoderState*>( - png_get_progressive_ptr(png_ptr)); - - // Mark the image as complete, this will tell the Decode function that we - // have successfully found the end of the data. - state->done = true; -} - -// Automatically destroys the given read structs on destruction to make -// cleanup and error handling code cleaner. -class PngReadStructDestroyer { - public: - PngReadStructDestroyer(png_struct** ps, png_info** pi) : ps_(ps), pi_(pi) { - } - ~PngReadStructDestroyer() { - png_destroy_read_struct(ps_, pi_, NULL); - } - private: - png_struct** ps_; - png_info** pi_; -}; - -bool BuildPNGStruct(const unsigned char* input, size_t input_size, - png_struct** png_ptr, png_info** info_ptr) { - if (input_size < 8) - return false; // Input data too small to be a png - - // Have libpng check the signature, it likes the first 8 bytes. - if (png_sig_cmp(const_cast<unsigned char*>(input), 0, 8) != 0) - return false; - - *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); - if (!*png_ptr) - return false; - - *info_ptr = png_create_info_struct(*png_ptr); - if (!*info_ptr) { - png_destroy_read_struct(png_ptr, NULL, NULL); - return false; - } - - return true; -} - -} // namespace - -// static -bool Decode(const unsigned char* input, size_t input_size, - ColorFormat format, std::vector<unsigned char>* output, - int* w, int* h) { - png_struct* png_ptr = NULL; - png_info* info_ptr = NULL; - if (!BuildPNGStruct(input, input_size, &png_ptr, &info_ptr)) - return false; - - PngReadStructDestroyer destroyer(&png_ptr, &info_ptr); - if (setjmp(png_jmpbuf(png_ptr))) { - // The destroyer will ensure that the structures are cleaned up in this - // case, even though we may get here as a jump from random parts of the - // PNG library called below. - return false; - } - - PngDecoderState state(format, output); - - png_set_progressive_read_fn(png_ptr, &state, &DecodeInfoCallback, - &DecodeRowCallback, &DecodeEndCallback); - png_process_data(png_ptr, - info_ptr, - const_cast<unsigned char*>(input), - input_size); - - if (!state.done) { - // Fed it all the data but the library didn't think we got all the data, so - // this file must be truncated. - output->clear(); - return false; - } - - *w = state.width; - *h = state.height; - return true; -} - -// Encoder -// -// This section of the code is based on nsPNGEncoder.cpp in Mozilla -// (Copyright 2005 Google Inc.) - -namespace { - -// Passed around as the io_ptr in the png structs so our callbacks know where -// to write data. -struct PngEncoderState { - explicit PngEncoderState(std::vector<unsigned char>* o) : out(o) {} - std::vector<unsigned char>* out; -}; - -// Called by libpng to flush its internal buffer to ours. -void EncoderWriteCallback(png_structp png, png_bytep data, png_size_t size) { - PngEncoderState* state = static_cast<PngEncoderState*>(png_get_io_ptr(png)); - size_t old_size = state->out->size(); - state->out->resize(old_size + size); - memcpy(&(*state->out)[old_size], data, size); -} - -void FakeFlushCallback(png_structp png) { - // We don't need to perform any flushing since we aren't doing real IO, but - // we're required to provide this function by libpng. -} - -void ConvertBGRAtoRGB(const unsigned char* bgra, int pixel_width, - unsigned char* rgb, bool* is_opaque) { - for (int x = 0; x < pixel_width; x++) { - const unsigned char* pixel_in = &bgra[x * 4]; - unsigned char* pixel_out = &rgb[x * 3]; - pixel_out[0] = pixel_in[2]; - pixel_out[1] = pixel_in[1]; - pixel_out[2] = pixel_in[0]; - } -} - -#ifdef PNG_TEXT_SUPPORTED - -inline char* strdup(const char* str) { -#if defined(OS_WIN) - return _strdup(str); -#else - return ::strdup(str); -#endif -} - -class CommentWriter { - public: - explicit CommentWriter(const std::vector<Comment>& comments) - : comments_(comments), - png_text_(new png_text[comments.size()]) { - for (size_t i = 0; i < comments.size(); ++i) - AddComment(i, comments[i]); - } - - ~CommentWriter() { - for (size_t i = 0; i < comments_.size(); ++i) { - free(png_text_[i].key); - free(png_text_[i].text); - } - delete [] png_text_; - } - - bool HasComments() { - return !comments_.empty(); - } - - png_text* get_png_text() { - return png_text_; - } - - int size() { - return static_cast<int>(comments_.size()); - } - - private: - void AddComment(size_t pos, const Comment& comment) { - png_text_[pos].compression = PNG_TEXT_COMPRESSION_NONE; - // A PNG comment's key can only be 79 characters long. - if (comment.key.length() > 79) - return; - png_text_[pos].key = strdup(comment.key.substr(0, 78).c_str()); - png_text_[pos].text = strdup(comment.text.c_str()); - png_text_[pos].text_length = comment.text.length(); -#ifdef PNG_iTXt_SUPPORTED - png_text_[pos].itxt_length = 0; - png_text_[pos].lang = 0; - png_text_[pos].lang_key = 0; -#endif - } - - const std::vector<Comment> comments_; - png_text* png_text_; -}; -#endif // PNG_TEXT_SUPPORTED - -// The type of functions usable for converting between pixel formats. -typedef void (*FormatConverter)(const unsigned char* in, int w, - unsigned char* out, bool* is_opaque); - -// libpng uses a wacky setjmp-based API, which makes the compiler nervous. -// We constrain all of the calls we make to libpng where the setjmp() is in -// place to this function. -// Returns true on success. -bool DoLibpngWrite(png_struct* png_ptr, png_info* info_ptr, - PngEncoderState* state, - int width, int height, int row_byte_width, - const unsigned char* input, int compression_level, - int png_output_color_type, int output_color_components, - FormatConverter converter, - const std::vector<Comment>& comments) { -#ifdef PNG_TEXT_SUPPORTED - CommentWriter comment_writer(comments); -#endif - unsigned char* row_buffer = NULL; - - // Make sure to not declare any locals here -- locals in the presence - // of setjmp() in C++ code makes gcc complain. - - if (setjmp(png_jmpbuf(png_ptr))) { - delete[] row_buffer; - return false; - } - - png_set_compression_level(png_ptr, compression_level); - - // Set our callback for libpng to give us the data. - png_set_write_fn(png_ptr, state, EncoderWriteCallback, FakeFlushCallback); - - png_set_IHDR(png_ptr, info_ptr, width, height, 8, png_output_color_type, - PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, - PNG_FILTER_TYPE_DEFAULT); - -#ifdef PNG_TEXT_SUPPORTED - if (comment_writer.HasComments()) { - png_set_text(png_ptr, info_ptr, comment_writer.get_png_text(), - comment_writer.size()); - } -#endif - - png_write_info(png_ptr, info_ptr); - - if (!converter) { - // No conversion needed, give the data directly to libpng. - for (int y = 0; y < height; y ++) { - png_write_row(png_ptr, - const_cast<unsigned char*>(&input[y * row_byte_width])); - } - } else { - // Needs conversion using a separate buffer. - row_buffer = new unsigned char[width * output_color_components]; - for (int y = 0; y < height; y ++) { - converter(&input[y * row_byte_width], width, row_buffer, NULL); - png_write_row(png_ptr, row_buffer); - } - delete[] row_buffer; - } - - png_write_end(png_ptr, info_ptr); - return true; -} - -} // namespace - -// static -bool EncodeWithCompressionLevel(const unsigned char* input, ColorFormat format, - const int width, const int height, - int row_byte_width, - bool discard_transparency, - const std::vector<Comment>& comments, - int compression_level, - std::vector<unsigned char>* output) { - // Run to convert an input row into the output row format, NULL means no - // conversion is necessary. - FormatConverter converter = NULL; - - int input_color_components, output_color_components; - int png_output_color_type; - switch (format) { - case FORMAT_RGB: - input_color_components = 3; - output_color_components = 3; - png_output_color_type = PNG_COLOR_TYPE_RGB; - discard_transparency = false; - break; - - case FORMAT_RGBA: - input_color_components = 4; - if (discard_transparency) { - output_color_components = 3; - png_output_color_type = PNG_COLOR_TYPE_RGB; - converter = ConvertRGBAtoRGB; - } else { - output_color_components = 4; - png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA; - converter = NULL; - } - break; - - case FORMAT_BGRA: - input_color_components = 4; - if (discard_transparency) { - output_color_components = 3; - png_output_color_type = PNG_COLOR_TYPE_RGB; - converter = ConvertBGRAtoRGB; - } else { - output_color_components = 4; - png_output_color_type = PNG_COLOR_TYPE_RGB_ALPHA; - converter = ConvertBetweenBGRAandRGBA; - } - break; - - default: - NOTREACHED(); - return false; - } - - // Row stride should be at least as long as the length of the data. - if (input_color_components * width < row_byte_width) - return false; - - png_struct* png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, - NULL, NULL, NULL); - if (!png_ptr) - return false; - png_info* info_ptr = png_create_info_struct(png_ptr); - if (!info_ptr) { - png_destroy_write_struct(&png_ptr, NULL); - return false; - } - - PngEncoderState state(output); - bool success = DoLibpngWrite(png_ptr, info_ptr, &state, - width, height, row_byte_width, - input, compression_level, png_output_color_type, - output_color_components, converter, comments); - png_destroy_write_struct(&png_ptr, &info_ptr); - - return success; -} - -// static -bool Encode(const unsigned char* input, ColorFormat format, - const int width, const int height, int row_byte_width, - bool discard_transparency, - const std::vector<Comment>& comments, - std::vector<unsigned char>* output) { - return EncodeWithCompressionLevel(input, format, width, height, - row_byte_width, - discard_transparency, - comments, Z_DEFAULT_COMPRESSION, - output); -} - -// Decode a PNG into an RGBA pixel array. -bool DecodePNG(const unsigned char* input, size_t input_size, - std::vector<unsigned char>* output, - int* width, int* height) { - return Decode(input, input_size, FORMAT_RGBA, output, width, height); -} - -// Encode an RGBA pixel array into a PNG. -bool EncodeRGBAPNG(const unsigned char* input, - int width, - int height, - int row_byte_width, - std::vector<unsigned char>* output) { - return Encode(input, FORMAT_RGBA, - width, height, row_byte_width, false, - std::vector<Comment>(), output); -} - -// Encode an BGRA pixel array into a PNG. -bool EncodeBGRAPNG(const unsigned char* input, - int width, - int height, - int row_byte_width, - bool discard_transparency, - std::vector<unsigned char>* output) { - return Encode(input, FORMAT_BGRA, - width, height, row_byte_width, discard_transparency, - std::vector<Comment>(), output); -} - -} // namespace image_diff_png |