From 1838d8c62fe6b562753deedf87d44cab2f6aaf02 Mon Sep 17 00:00:00 2001
From: Ian Gulliver <flamingcow@gmail.com>
Date: Sat, 12 Aug 2017 12:01:21 -0700
Subject: [PATCH] Lut base class, ScoreImage -> ScoreLut

---
 Makefile       |  2 +-
 colorchecker.h |  6 +++---
 lut.cc         |  4 ++++
 lut.h          | 51 +++++++++++++++++++++++++++++---------------------
 piphoto.cc     |  5 +++--
 5 files changed, 41 insertions(+), 27 deletions(-)
 create mode 100644 lut.cc

diff --git a/Makefile b/Makefile
index 88111f5..1554d9c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 all: piphoto
 
-objects = piphoto.o util.o
+objects = piphoto.o lut.o util.o
 
 piphoto: $(objects) Makefile
 	clang-3.9 -O3 -g -Weverything -Werror --std=c++1z --stdlib=libc++ -o piphoto $(objects) -lc++ -lunwind -lpng
diff --git a/colorchecker.h b/colorchecker.h
index 13c2f91..41d7821 100644
--- a/colorchecker.h
+++ b/colorchecker.h
@@ -69,7 +69,7 @@ Array<Coord<2>, kColorCheckerSrgb.size()> FindClosest(const Image<X, Y, C>& imag
 }
 
 template <int32_t X, int32_t Y, int32_t C>
-int32_t ScoreImage(const Image<X, Y, C>& image) {
+int32_t ScoreLut(const Image<X, Y, C>& image, const Lut& lut) {
   static_assert(C == 3);
 
   Array<int32_t, kColorCheckerSrgb.size()> diff;
@@ -79,7 +79,7 @@ int32_t ScoreImage(const Image<X, Y, C>& image) {
     const auto& row = image.at(y);
 
     for (int32_t x = 0; x < X; ++x) {
-      const auto& pixel = row.at(x);
+      const auto pixel = lut.MapColor(row.at(x));
 
       for (int32_t cc = 0; cc < kColorCheckerSrgb.ssize(); ++cc) {
         auto pixel_diff = pixel.AbsDiff(kColorCheckerSrgb.at(cc));
@@ -138,7 +138,7 @@ int32_t OptimizeLut(const Image<IMG_X, IMG_Y, C>& image, Lut3d<LUT_X, LUT_Y, LUT
             [&image, &snapshot, x, y, z, c](int32_t val) {
               auto test_lut = snapshot;
               test_lut.at(x).at(y).at(z).at(c) = val;
-              return ScoreImage(*test_lut.MapImage(image));
+              return ScoreLut(image, test_lut);
             });
           // Magic value of 8 is the number of points making up a square, so the number
           // of points that control any given given LUT mapping.
diff --git a/lut.cc b/lut.cc
new file mode 100644
index 0000000..48f83df
--- /dev/null
+++ b/lut.cc
@@ -0,0 +1,4 @@
+#include "lut.h"
+
+Lut::~Lut() {
+}
diff --git a/lut.h b/lut.h
index 23bb116..65502de 100644
--- a/lut.h
+++ b/lut.h
@@ -3,17 +3,41 @@
 #include "array.h"
 #include "color.h"
 #include "coord.h"
+#include "image.h"
+
+class Lut {
+ public:
+  Lut() = default;
+  Lut(const Lut&) = default;
+  virtual ~Lut();
+
+  virtual Color<3> MapColor(const Color<3>& in) const = 0;
+
+  template <int32_t X, int32_t Y, int32_t C>
+  std::unique_ptr<Image<X, Y, C>> MapImage(const Image<X, Y, C>& in) const;
+};
+
+template <int32_t X, int32_t Y, int32_t C>
+std::unique_ptr<Image<X, Y, C>> Lut::MapImage(const Image<X, Y, C>& in) const {
+  auto out = std::make_unique<Image<X, Y, C>>();
+
+  for (int32_t y = 0; y < Y; ++y) {
+    for (int32_t x = 0; x < X; ++x) {
+      Coord<2> coord = {{{{x, y}}}};
+      out->SetPixel(coord, MapColor(in.GetPixel(coord)));
+    }
+  }
+
+  return out;
+}
+
 
-// Hardcoded to Color<3>, so color dimensions == LUT dimensions
 template <int32_t X, int32_t Y, int32_t Z>
-class Lut3d : public Array<Array<Array<Color<3>, X>, Y>, Z> {
+class Lut3d : public Array<Array<Array<Color<3>, X>, Y>, Z>, public Lut {
  public:
   static Lut3d<X, Y, Z> Identity();
 
-  Color<3> MapColor(const Color<3>& in) const;
-
-  template <int32_t IMG_X, int32_t IMG_Y, int32_t C>
-  std::unique_ptr<Image<IMG_X, IMG_Y, C>> MapImage(const Image<IMG_X, IMG_Y, C>& in) const;
+  Color<3> MapColor(const Color<3>& in) const override;
 
  private:
   // Return value is (root_indices, remainders)
@@ -82,21 +106,6 @@ Color<3> Lut3d<X, Y, Z>::MapColor(const Color<3>& in) const {
   return inter0.Interpolate(inter1, rem.at(2), BlockSize(Z)).Crop();
 }
 
-template <int32_t X, int32_t Y, int32_t Z>
-template <int32_t IMG_X, int32_t IMG_Y, int32_t C>
-std::unique_ptr<Image<IMG_X, IMG_Y, C>> Lut3d<X, Y, Z>::MapImage(const Image<IMG_X, IMG_Y, C>& in) const {
-  auto out = std::make_unique<Image<IMG_X, IMG_Y, C>>();
-
-  for (int32_t y = 0; y < IMG_Y; ++y) {
-    for (int32_t x = 0; x < IMG_X; ++x) {
-      Coord<2> coord = {{{{x, y}}}};
-      out->SetPixel(coord, MapColor(in.GetPixel(coord)));
-    }
-  }
-
-  return out;
-}
-
 template <int32_t X, int32_t Y, int32_t Z>
 constexpr std::pair<Coord<3>, Coord<3>> Lut3d<X, Y, Z>::FindRoot(const Color<3>& in) {
   auto root_x = FindChannelRoot(in.at(0), X);
diff --git a/piphoto.cc b/piphoto.cc
index 9586b8b..c50fa03 100644
--- a/piphoto.cc
+++ b/piphoto.cc
@@ -8,13 +8,14 @@
 int main() {
   auto image = PiRaw2::FromJpeg(ReadFile("test.jpg"));
   WriteFile("start.png", HighlightClosest(*image)->ToPng());
-  std::cout << "Initial error: " << ScoreImage(*image) << std::endl;
 
   auto lut = MinimalLut3d::Identity();
+  std::cout << "Initial error: " << ScoreLut(*image, lut) << std::endl;
+
   int32_t diff = 1;
   while (diff) {
     diff = OptimizeLut<4>(*image, &lut);
-    std::cout << "diff=" << diff << " error=" << ScoreImage(*lut.MapImage(*image)) << std::endl;
+    std::cout << "diff=" << diff << " error=" << ScoreLut(*image, lut) << std::endl;
     WriteFile("inter.png", HighlightClosest(*lut.MapImage(*image))->ToPng());
   }