Add interesting features to visualize_color_gamut
(1) Draw triangles onto a D50 color gamut so they are
actually in the correct place.
(2) Add options to display canonical sRGB and Adobe RGB
gamuts.
(3) Label the R, G, and B points of the color gamut.
(4) Decode and reencode the input image without color
correction, so we can compare to the corrected version.
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2017153002
Review-Url: https://codereview.chromium.org/2017153002
diff --git a/resources/gamut.png b/resources/gamut.png
index 8fb2ce9..7e3782b 100644
--- a/resources/gamut.png
+++ b/resources/gamut.png
Binary files differ
diff --git a/tools/visualize_color_gamut.cpp b/tools/visualize_color_gamut.cpp
index 8fdd962..bc40152 100644
--- a/tools/visualize_color_gamut.cpp
+++ b/tools/visualize_color_gamut.cpp
@@ -19,8 +19,11 @@
__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.");
+DEFINE_string(input, "input.png", "A path to the input image.");
+DEFINE_string(output, "output.png", "A path to the output image.");
+DEFINE_bool(sRGB, false, "Draws the sRGB gamut.");
+DEFINE_bool(adobeRGB, false, "Draws the Adobe RGB gamut.");
+DEFINE_string(uncorrected, "", "A path to reencode the uncorrected input image.");
/**
* Loads the triangular gamut as a set of three points.
@@ -43,18 +46,71 @@
/**
* Calculates the area of the triangular gamut.
*/
-float calculate_area(SkPoint abc[]) {
+static 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);
}
+static void draw_gamut(SkCanvas* canvas, const SkMatrix44& xyz, const char* name, SkColor color,
+ bool label) {
+ // Report the XYZ values.
+ SkDebugf("%s\n", name);
+ SkDebugf(" X Y Z\n");
+ SkDebugf("Red %.3f %.3f %.3f\n", xyz.get(0, 0), xyz.get(0, 1), xyz.get(0, 2));
+ SkDebugf("Green %.3f %.3f %.3f\n", xyz.get(1, 0), xyz.get(1, 1), xyz.get(1, 2));
+ SkDebugf("Blue %.3f %.3f %.3f\n", xyz.get(2, 0), xyz.get(2, 1), xyz.get(2, 2));
+
+ // Calculate the points in the gamut from the XYZ values.
+ SkPoint rgb[4];
+ load_gamut(rgb, xyz);
+
+ // Report the area of the gamut.
+ SkDebugf("Area of Gamut: %.3f\n\n", calculate_area(rgb));
+
+ // Magic constants that help us place the gamut triangles in the appropriate position
+ // on the canvas.
+ const float xScale = 2071.25f; // Num pixels from 0 to 1 in x
+ const float xOffset = 241.0f; // Num pixels until start of x-axis
+ const float yScale = 2067.78f; // Num pixels from 0 to 1 in y
+ const float yOffset = -144.78f; // Num pixels until start of y-axis
+ // (negative because y extends beyond image bounds)
+
+ // Now transform the points so they can be drawn on our canvas.
+ // Note that y increases as we move down the canvas.
+ rgb[0].fX = xOffset + xScale * rgb[0].fX;
+ rgb[0].fY = yOffset + yScale * (1.0f - rgb[0].fY);
+ rgb[1].fX = xOffset + xScale * rgb[1].fX;
+ rgb[1].fY = yOffset + yScale * (1.0f - rgb[1].fY);
+ rgb[2].fX = xOffset + xScale * rgb[2].fX;
+ rgb[2].fY = yOffset + yScale * (1.0f - rgb[2].fY);
+
+ // Repeat the first point to connect the polygon.
+ rgb[3] = rgb[0];
+ SkPaint paint;
+ paint.setColor(color);
+ paint.setStrokeWidth(6.0f);
+ paint.setTextSize(75.0f);
+ canvas->drawPoints(SkCanvas::kPolygon_PointMode, 4, rgb, paint);
+ if (label) {
+ canvas->drawText("R", 1, rgb[0].fX + 5.0f, rgb[0].fY + 75.0f, paint);
+ canvas->drawText("G", 1, rgb[1].fX + 5.0f, rgb[1].fY - 5.0f, paint);
+ canvas->drawText("B", 1, rgb[2].fX - 75.0f, rgb[2].fY - 5.0f, paint);
+ }
+}
+
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");
+ "Usage: visualize_color_gamut --input <path to input image> "
+ "--output <path to output image> "
+ "--sRGB <draw canonical sRGB gamut> "
+ "--adobeRGB <draw canonical Adobe RGB gamut> "
+ "--uncorrected <path to reencoded, uncorrected "
+ " input image>\n"
+ "Description: Writes a visualization of the color gamut to the output image ."
+ "Also, if a path is provided, writes uncorrected bytes to an unmarked "
+ "png, for comparison with the input image.\n");
SkCommandLineFlags::Parse(argc, argv);
const char* input = FLAGS_input[0];
const char* output = FLAGS_output[0];
@@ -75,61 +131,71 @@
}
// Load a graph of the CIE XYZ color gamut.
- SkBitmap bitmap;
- if (!GetResourceAsBitmap("gamut.png", &bitmap)) {
+ SkBitmap gamut;
+ if (!GetResourceAsBitmap("gamut.png", &gamut)) {
SkDebugf("Program failure.\n");
return -1;
}
- SkCanvas canvas(bitmap);
+ SkCanvas canvas(gamut);
+ // Draw the sRGB gamut if requested.
+ if (FLAGS_sRGB) {
+ sk_sp<SkColorSpace> sRGBSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named);
+ draw_gamut(&canvas, sRGBSpace->xyz(), "sRGB", 0xFFFF9394, false);
+ }
+
+ // Draw the Adobe RGB gamut if requested.
+ if (FLAGS_adobeRGB) {
+ sk_sp<SkColorSpace> adobeRGBSpace = SkColorSpace::NewNamed(SkColorSpace::kAdobeRGB_Named);
+ draw_gamut(&canvas, adobeRGBSpace->xyz(), "Adobe RGB", 0xFF31a9e1, false);
+ }
+
+ // Draw gamut for the input image.
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);
}
+ draw_gamut(&canvas, colorSpace->xyz(), input, 0xFF000000, true);
- // 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));
+ // Finally, encode the result to the output file.
+ SkAutoTUnref<SkData> out(SkImageEncoder::EncodeData(gamut, SkImageEncoder::kPNG_Type, 100));
if (!out) {
- SkDebugf("Failed to encode output.\n");
+ SkDebugf("Failed to encode gamut output.\n");
return -1;
}
SkFILEWStream stream(output);
bool result = stream.write(out->data(), out->size());
if (!result) {
- SkDebugf("Failed to write output.\n");
+ SkDebugf("Failed to write gamut output.\n");
return -1;
}
+ // Also, if requested, decode and reencode the uncorrected input image.
+ if (!FLAGS_uncorrected.isEmpty()) {
+ SkBitmap bitmap;
+ int width = codec->getInfo().width();
+ int height = codec->getInfo().height();
+ SkAlphaType alphaType = codec->getInfo().alphaType();
+ bitmap.allocN32Pixels(width, height, kOpaque_SkAlphaType == alphaType);
+ SkImageInfo decodeInfo = SkImageInfo::MakeN32(width, height, alphaType);
+ if (SkCodec::kSuccess != codec->getPixels(decodeInfo, bitmap.getPixels(),
+ bitmap.rowBytes())) {
+ SkDebugf("Could not decode input image.\n");
+ return -1;
+ }
+ out.reset(SkImageEncoder::EncodeData(bitmap, SkImageEncoder::kPNG_Type, 100));
+ if (!out) {
+ SkDebugf("Failed to encode uncorrected image.\n");
+ return -1;
+ }
+ SkFILEWStream bitmapStream(FLAGS_uncorrected[0]);
+ result = bitmapStream.write(out->data(), out->size());
+ if (!result) {
+ SkDebugf("Failed to write uncorrected image output.\n");
+ return -1;
+ }
+ }
+
return 0;
}
