diff options
| -rw-r--r-- | gyp/tools.gyp | 18 | ||||
| -rw-r--r-- | resources/gamut.png | bin | 0 -> 131981 bytes | |||
| -rw-r--r-- | tools/visualize_color_gamut.cpp | 135 |
3 files changed, 153 insertions, 0 deletions
diff --git a/gyp/tools.gyp b/gyp/tools.gyp index a1d4deef73..ab8b4c6d8b 100644 --- a/gyp/tools.gyp +++ b/gyp/tools.gyp @@ -32,6 +32,7 @@ 'skpmaker', 'test_public_includes', 'using_skia_and_harfbuzz', + 'visualize_color_gamut', 'whitelist_typefaces', ], 'conditions': [ @@ -422,6 +423,23 @@ 'xcode_settings': { 'WARNING_CFLAGS': [ '-w', ], }, }, { + 'target_name': 'visualize_color_gamut', + 'type': 'executable', + 'sources': [ + '../tools/visualize_color_gamut.cpp', + ], + 'include_dirs': [ + '../src/core', + '../include/private', + '../tools', + ], + 'dependencies': [ + 'flags.gyp:flags', + 'resources', + 'skia_lib.gyp:skia_lib', + ], + }, + { 'target_name': 'whitelist_typefaces', 'type': 'executable', 'sources': [ diff --git a/resources/gamut.png b/resources/gamut.png Binary files differnew file mode 100644 index 0000000000..8fb2ce9b7f --- /dev/null +++ b/resources/gamut.png diff --git a/tools/visualize_color_gamut.cpp b/tools/visualize_color_gamut.cpp new file mode 100644 index 0000000000..8fdd962185 --- /dev/null +++ b/tools/visualize_color_gamut.cpp @@ -0,0 +1,135 @@ +/* + * Copyright 2016 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "Resources.h" + +#include "SkBitmap.h" +#include "SkCanvas.h" +#include "SkCodec.h" +#include "SkColorSpace.h" +#include "SkCommandLineFlags.h" +#include "SkForceLinking.h" +#include "SkImageEncoder.h" +#include "SkMatrix44.h" +#include "SkOSFile.h" + +__SK_FORCE_IMAGE_DECODER_LINKING; + +DEFINE_string2(input, i, "input.png", "A path to the input image."); +DEFINE_string2(output, o, "output.png", "A path to the output image."); + +/** + * Loads the triangular gamut as a set of three points. + */ +static void load_gamut(SkPoint rgb[], const SkMatrix44& xyz) { + // rx = rX / (rX + rY + rZ) + // ry = rX / (rX + rY + rZ) + // gx, gy, bx, and gy are calulcated similarly. + float rSum = xyz.get(0, 0) + xyz.get(0, 1) + xyz.get(0, 2); + float gSum = xyz.get(1, 0) + xyz.get(1, 1) + xyz.get(1, 2); + float bSum = xyz.get(2, 0) + xyz.get(2, 1) + xyz.get(2, 2); + rgb[0].fX = xyz.get(0, 0) / rSum; + rgb[0].fY = xyz.get(0, 1) / rSum; + rgb[1].fX = xyz.get(1, 0) / gSum; + rgb[1].fY = xyz.get(1, 1) / gSum; + rgb[2].fX = xyz.get(2, 0) / bSum; + rgb[2].fY = xyz.get(2, 1) / bSum; +} + +/** + * Calculates the area of the triangular gamut. + */ +float calculate_area(SkPoint abc[]) { + SkPoint a = abc[0]; + SkPoint b = abc[1]; + SkPoint c = abc[2]; + return 0.5f * SkTAbs(a.fX*b.fY + b.fX*c.fY - a.fX*c.fY - c.fX*b.fY - b.fX*a.fY); +} + +int main(int argc, char** argv) { + SkCommandLineFlags::SetUsage( + "Usage: visualize_color_gamut --input <path to input image>" + "--output <path to output image>\n" + "Description: Writes a visualization of the color gamut to the output image\n"); + SkCommandLineFlags::Parse(argc, argv); + const char* input = FLAGS_input[0]; + const char* output = FLAGS_output[0]; + if (!input || !output) { + SkCommandLineFlags::PrintUsage(); + return -1; + } + + SkAutoTUnref<SkData> data(SkData::NewFromFileName(input)); + if (!data) { + SkDebugf("Cannot find input image.\n"); + return -1; + } + SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(data)); + if (!codec) { + SkDebugf("Invalid input image.\n"); + return -1; + } + + // Load a graph of the CIE XYZ color gamut. + SkBitmap bitmap; + if (!GetResourceAsBitmap("gamut.png", &bitmap)) { + SkDebugf("Program failure.\n"); + return -1; + } + SkCanvas canvas(bitmap); + + sk_sp<SkColorSpace> colorSpace = sk_ref_sp(codec->getColorSpace()); + if (!colorSpace) { + SkDebugf("Image had no embedded color space information. Defaulting to sRGB.\n"); + colorSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named); + } + + // Calculate the points in the gamut from the XYZ values. + SkMatrix44 xyz = colorSpace->xyz(); + SkPoint rgb[4]; + load_gamut(rgb, xyz); + + // Report the XYZ values. + SkDebugf(" X Y Z\n"); + SkDebugf("Red %.2f %.2f %.2f\n", xyz.get(0, 0), xyz.get(0, 1), xyz.get(0, 2)); + SkDebugf("Green %.2f %.2f %.2f\n", xyz.get(1, 0), xyz.get(1, 1), xyz.get(1, 2)); + SkDebugf("Blue %.2f %.2f %.2f\n", xyz.get(2, 0), xyz.get(2, 1), xyz.get(2, 2)); + + // Report the area of the gamut. + SkDebugf("Area of Gamut: %g\n", calculate_area(rgb)); + + // Now transform the points so they can be drawn on our canvas. We use 1000 pixels + // to represent the space from 0 to 1. Note that the graph is at an offset of (50, 50). + // Also note that y increases as we move down the canvas. + rgb[0].fX = 50 + 1000*rgb[0].fX; + rgb[0].fY = 50 + 1000*(1 - rgb[0].fY); + rgb[1].fX = 50 + 1000*rgb[1].fX; + rgb[1].fY = 50 + 1000*(1 - rgb[1].fY); + rgb[2].fX = 50 + 1000*rgb[2].fX; + rgb[2].fY = 50 + 1000*(1 - rgb[2].fY); + + // Repeat the first point to connect the polygon. + rgb[3] = rgb[0]; + + SkPaint paint; + canvas.drawPoints(SkCanvas::kPolygon_PointMode, 4, rgb, paint); + + // Finally, encode the result to out.png. + SkAutoTUnref<SkData> out(SkImageEncoder::EncodeData(bitmap, SkImageEncoder::kPNG_Type, 100)); + if (!out) { + SkDebugf("Failed to encode output.\n"); + return -1; + } + SkFILEWStream stream(output); + bool result = stream.write(out->data(), out->size()); + if (!result) { + SkDebugf("Failed to write output.\n"); + return -1; + } + + return 0; +} |
