diff options
Diffstat (limited to 'xBRZ/src/xbrz.cpp')
| -rw-r--r-- | xBRZ/src/xbrz.cpp | 43 |
1 files changed, 24 insertions, 19 deletions
diff --git a/xBRZ/src/xbrz.cpp b/xBRZ/src/xbrz.cpp index 6c015aa1..659614fd 100644 --- a/xBRZ/src/xbrz.cpp +++ b/xBRZ/src/xbrz.cpp @@ -27,8 +27,10 @@ using namespace xbrz; namespace { +//blend front color with opacity M / N over opaque background: https://en.wikipedia.org/wiki/Alpha_compositing + //TODO!? gamma correction: https://en.wikipedia.org/wiki/Alpha_compositing#Gamma_correction template <unsigned int M, unsigned int N> inline -uint32_t gradientRGB(uint32_t pixFront, uint32_t pixBack) //blend front color with opacity M / N over opaque background: https://en.wikipedia.org/wiki/Alpha_compositing#Alpha_blending +uint32_t gradientRGB(uint32_t pixFront, uint32_t pixBack) { static_assert(0 < M && M < N && N <= 1000); @@ -43,8 +45,10 @@ uint32_t gradientRGB(uint32_t pixFront, uint32_t pixBack) //blend front color wi } +//find intermediate color between two colors with alpha channels (=> NO alpha blending!!!) +//TODO!? gamma correction: https://en.wikipedia.org/wiki/Alpha_compositing#Gamma_correction template <unsigned int M, unsigned int N> inline -uint32_t gradientARGB(uint32_t pixFront, uint32_t pixBack) //find intermediate color between two colors with alpha channels (=> NO alpha blending!!!) +uint32_t gradientARGB(uint32_t pixFront, uint32_t pixBack) { static_assert(0 < M && M < N && N <= 1000); @@ -153,10 +157,11 @@ double distRGB(uint32_t pix1, uint32_t pix2) inline -double distYCbCr(uint32_t pix1, uint32_t pix2, double lumaWeight) +double distYCbCr(uint32_t pix1, uint32_t pix2, double /*testAttribute*/) { //https://en.wikipedia.org/wiki/YCbCr#ITU-R_BT.601_conversion - //YCbCr conversion is a matrix multiplication => take advantage of linearity by subtracting first! + //Y'CbCr conversion is a matrix multiplication => take advantage of linearity by subtracting first! + //NOTE: input is gamma-encoded RGB! => what does this mean for the output distance!?? const int r_diff = static_cast<int>(getRed (pix1)) - getRed (pix2); //defer division by 255 to after matrix multiplication const int g_diff = static_cast<int>(getGreen(pix1)) - getGreen(pix2); // const int b_diff = static_cast<int>(getBlue (pix1)) - getBlue (pix2); //substraction for int is noticeable faster than for double! @@ -175,12 +180,12 @@ double distYCbCr(uint32_t pix1, uint32_t pix2, double lumaWeight) const double c_r = scale_r * (r_diff - y); //we skip division by 255 to have similar range like other distance functions - return std::sqrt(square(lumaWeight * y) + square(c_b) + square(c_r)); + return std::sqrt(square(y) + square(c_b) + square(c_r)); } inline -double distYCbCrBuffered(uint32_t pix1, uint32_t pix2) +double distYCbCrBuffered(uint32_t pix1, uint32_t pix2, double /*testAttribute*/) { //30% perf boost compared to plain distYCbCr()! //consumes 64 MB memory; using double is only 2% faster, but takes 128 MB @@ -287,7 +292,7 @@ BlendResult preProcessCorners(const Kernel_4x4& ker, const xbrz::ScalerCfg& cfg) ker.f == ker.i)) return result; - auto dist = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.luminanceWeight); }; + auto dist = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.testAttribute); }; const double hf = dist(ker.g, ker.e) + dist(ker.e, ker.c) + dist(ker.k, ker.i) + dist(ker.i, ker.o) + cfg.centerDirectionBias * dist(ker.h, ker.f); const double ei = dist(ker.d, ker.h) + dist(ker.h, ker.l) + dist(ker.b, ker.f) + dist(ker.f, ker.n) + cfg.centerDirectionBias * dist(ker.e, ker.i); @@ -394,8 +399,8 @@ void blendPixel(const Kernel_3x3& ker, if (getBottomR(blend) >= BLEND_NORMAL) { - auto eq = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.luminanceWeight) < cfg.equalColorTolerance; }; - auto dist = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.luminanceWeight); }; + auto eq = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.testAttribute) < cfg.equalColorTolerance; }; + auto dist = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.testAttribute); }; const bool doLineBlend = [&]() -> bool { @@ -1081,9 +1086,9 @@ struct Scaler6x : public ColorGradient struct ColorDistanceRGB { - static double dist(uint32_t pix1, uint32_t pix2, double luminanceWeight) + static double dist(uint32_t pix1, uint32_t pix2, double testAttribute) { - return distYCbCrBuffered(pix1, pix2); + return distYCbCrBuffered(pix1, pix2, testAttribute); //if (pix1 == pix2) //about 4% perf boost // return 0; @@ -1093,7 +1098,7 @@ struct ColorDistanceRGB struct ColorDistanceARGB { - static double dist(uint32_t pix1, uint32_t pix2, double luminanceWeight) + static double dist(uint32_t pix1, uint32_t pix2, double testAttribute) { const double a1 = getAlpha(pix1) / 255.0 ; const double a2 = getAlpha(pix2) / 255.0 ; @@ -1109,7 +1114,7 @@ struct ColorDistanceARGB alternative? std::sqrt(a1 * a2 * square(distYCbCrBuffered(pix1, pix2)) + square(255 * (a1 - a2))); */ //=> following code is 15% faster: - const double d = distYCbCrBuffered(pix1, pix2); + const double d = distYCbCrBuffered(pix1, pix2, testAttribute); if (a1 < a2) return a1 * d + 255 * (a2 - a1); else @@ -1120,12 +1125,12 @@ struct ColorDistanceARGB struct ColorDistanceUnbufferedARGB { - static double dist(uint32_t pix1, uint32_t pix2, double luminanceWeight) + static double dist(uint32_t pix1, uint32_t pix2, double testAttribute) { const double a1 = getAlpha(pix1) / 255.0 ; const double a2 = getAlpha(pix2) / 255.0 ; - const double d = distYCbCr(pix1, pix2, luminanceWeight); + const double d = distYCbCr(pix1, pix2, testAttribute); if (a1 < a2) return a1 * d + 255 * (a2 - a1); else @@ -1204,16 +1209,16 @@ void xbrz::scale(size_t factor, const uint32_t* src, uint32_t* trg, int srcWidth } -bool xbrz::equalColorTest(uint32_t col1, uint32_t col2, ColorFormat colFmt, double luminanceWeight, double equalColorTolerance) +bool xbrz::equalColorTest2(uint32_t col1, uint32_t col2, ColorFormat colFmt, double equalColorTolerance, double testAttribute) { switch (colFmt) { case ColorFormat::rgb: - return ColorDistanceRGB::dist(col1, col2, luminanceWeight) < equalColorTolerance; + return ColorDistanceRGB::dist(col1, col2, testAttribute) < equalColorTolerance; case ColorFormat::argb: - return ColorDistanceARGB::dist(col1, col2, luminanceWeight) < equalColorTolerance; + return ColorDistanceARGB::dist(col1, col2, testAttribute) < equalColorTolerance; case ColorFormat::argbUnbuffered: - return ColorDistanceUnbufferedARGB::dist(col1, col2, luminanceWeight) < equalColorTolerance; + return ColorDistanceUnbufferedARGB::dist(col1, col2, testAttribute) < equalColorTolerance; } assert(false); return false; |