| /* |
| * 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; |
| } |