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Working identity LUT

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This commit is contained in:
Ian Gulliver
2017-08-07 06:15:20 +00:00
parent 89a54867f3
commit 100c44fe4e
7 changed files with 81 additions and 14 deletions
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52
lut.h
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@@ -11,8 +11,13 @@ struct Coord3d {
template <uint32_t R, uint32_t G, uint32_t B>
class Lut3d : public std::array<std::array<std::array<Color, B>, G>, R> {
public:
static std::unique_ptr<Lut3d<R, G, B>> Identity();
Color MapColor(const Color& in) const;
template <uint32_t X, uint32_t Y>
std::unique_ptr<Image<X, Y>> MapImage(const Image<X, Y>& in) const;
private:
constexpr static Color InterpolateColor(const Color& i0, const Color& i1, uint32_t mul, uint32_t div);
constexpr static uint32_t Interpolate(uint32_t i0, uint32_t i1, uint32_t mul, uint32_t div);
@@ -24,6 +29,29 @@ class Lut3d : public std::array<std::array<std::array<Color, B>, G>, R> {
constexpr static uint32_t BlockSize(uint32_t points);
};
template <uint32_t R, uint32_t G, uint32_t B>
std::unique_ptr<Lut3d<R, G, B>> Lut3d<R, G, B>::Identity() {
auto ret = std::make_unique<Lut3d<R, G, B>>();
Color color;
for (uint32_t r = 0; r < R; ++r) {
auto& rect = ret->at(r);
color.r = std::min(kNumColors - 1, BlockSize(R) * r);
for (uint32_t g = 0; g < G; ++g) {
auto& row = rect.at(g);
color.g = std::min(kNumColors - 1, BlockSize(G) * g);
for (uint32_t b = 0; b < B; ++b) {
color.b = std::min(kNumColors - 1, BlockSize(B) * b);
row.at(b) = color;
}
}
}
return ret;
}
template <uint32_t R, uint32_t G, uint32_t B>
Color Lut3d<R, G, B>::MapColor(const Color& in) const {
const auto root_rem = FindRoot(in);
@@ -61,6 +89,21 @@ Color Lut3d<R, G, B>::MapColor(const Color& in) const {
return InterpolateColor(inter0, inter1, rem.b, BlockSize(B));
}
template <uint32_t R, uint32_t G, uint32_t B>
template <uint32_t X, uint32_t Y>
std::unique_ptr<Image<X, Y>> Lut3d<R, G, B>::MapImage(const Image<X, Y>& in) const {
auto out = std::make_unique<Image<X, Y>>();
for (uint32_t y = 0; y < Y; ++y) {
for (uint32_t x = 0; x < X; ++x) {
Coord coord = {x, y};
out->SetPixel(coord, MapColor(in.GetPixel(coord)));
}
}
return out;
}
template <uint32_t R, uint32_t G, uint32_t B>
constexpr Color Lut3d<R, G, B>::InterpolateColor(const Color& i0, const Color& i1, uint32_t mul, uint32_t div) {
return {
@@ -72,14 +115,15 @@ constexpr Color Lut3d<R, G, B>::InterpolateColor(const Color& i0, const Color& i
template <uint32_t R, uint32_t G, uint32_t B>
constexpr uint32_t Lut3d<R, G, B>::Interpolate(uint32_t i0, uint32_t i1, uint32_t mul, uint32_t div) {
return i0 + ((mul * i1) / div);
assert(i1 >= i0);
return i0 + ((mul * (i1 - i0)) / div);
}
template <uint32_t R, uint32_t G, uint32_t B>
constexpr std::pair<Coord3d, Coord3d> Lut3d<R, G, B>::FindRoot(const Color& in) {
auto root_r = FindChannelRoot(in.r, R);
auto root_g = FindChannelRoot(in.r, G);
auto root_b = FindChannelRoot(in.r, B);
auto root_g = FindChannelRoot(in.g, G);
auto root_b = FindChannelRoot(in.b, B);
return {
{root_r.first, root_g.first, root_b.first},
{root_r.second, root_g.second, root_b.second},
@@ -95,6 +139,6 @@ constexpr std::pair<uint32_t, uint32_t> Lut3d<R, G, B>::FindChannelRoot(const ui
}
template <uint32_t R, uint32_t G, uint32_t B>
constexpr uint32_t BlockSize(uint32_t points) {
constexpr uint32_t Lut3d<R, G, B>::BlockSize(uint32_t points) {
return kNumColors / (points - 1);
}