Calculate color minimums

This commit is contained in:
Ian Gulliver
2017-08-06 00:05:37 +00:00
parent 9000d646c7
commit 5555505446

View File

@@ -18,23 +18,107 @@ using string_view = experimental::string_view;
std::string ReadFile(const std::string& filename);
void WriteFile(const std::string& filename, const std::string& contents);
template <uint32_t X, uint32_t Y, uint32_t D, uint32_t A, uint32_t P>
class PiRaw {
public:
struct Pixel {
struct Pixel {
// 32-bit for compiler convenience, but values are 16-bit
uint32_t r;
uint32_t g;
uint32_t b;
};
typedef std::array<std::array<Pixel, X>, Y> Image;
PiRaw(std::unique_ptr<Image>);
uint32_t Difference(const Pixel& other) const;
};
uint32_t Pixel::Difference(const Pixel& other) const {
return (
((r > other.r) ? (r - other.r) : (other.r - r)) +
((g > other.g) ? (g - other.g) : (other.g - g)) +
((b > other.b) ? (b - other.b) : (other.b - b))
);
}
constexpr uint32_t kNumColorChecker = 24;
constexpr std::array<Pixel, kNumColorChecker> kColorCheckerSrgb = {{
{0x7300, 0x5200, 0x4400},
{0xc200, 0x9600, 0x8200},
{0x6200, 0x7a00, 0x9d00},
{0x5700, 0x6c00, 0x4300},
{0x8500, 0x8000, 0xb100},
{0x6700, 0xbd00, 0xaa00},
{0xd600, 0x7e00, 0x2c00},
{0x5000, 0x5b00, 0xa600},
{0xc100, 0x5a00, 0x6300},
{0x5e00, 0x3c00, 0x6c00},
{0x9d00, 0xbc00, 0x4000},
{0xe000, 0xa300, 0x2e00},
{0x3800, 0x3d00, 0x9600},
{0x4600, 0x9400, 0x4900},
{0xaf00, 0x3600, 0x3c00},
{0xe700, 0xc700, 0x1f00},
{0xbb00, 0x5600, 0x9500},
{0x0800, 0x8500, 0xa100},
{0xf300, 0xf300, 0xf200},
{0xc800, 0xc800, 0xc800},
{0xa000, 0xa000, 0xa000},
{0x7a00, 0x7a00, 0x7900},
{0x5500, 0x5500, 0x5500},
{0x3400, 0x3400, 0x3400},
}};
struct Coord {
uint32_t x;
uint32_t y;
};
std::ostream& operator<<(std::ostream& os, const Coord& coord);
std::ostream& operator<<(std::ostream& os, const Coord& coord) {
return os << "(" << coord.x << ", " << coord.y << ")";
}
template <uint32_t X, uint32_t Y>
struct Image : public std::array<std::array<Pixel, X>, Y> {
std::array<Coord, kNumColorChecker> ColorCheckerClosest() const;
};
template <uint32_t X, uint32_t Y>
std::array<Coord, kNumColorChecker> Image<X, Y>::ColorCheckerClosest() const {
std::array<Coord, kNumColorChecker> closest;
std::array<uint32_t, kNumColorChecker> diff;
diff.fill(UINT32_MAX);
for (uint32_t y = 0; y < Y; ++y) {
const auto& row = this->at(y);
for (uint32_t x = 0; x < X; ++x) {
const auto& pixel = row.at(x);
for (uint32_t cc = 0; cc < kNumColorChecker; ++cc) {
auto pixel_diff = pixel.Difference(kColorCheckerSrgb.at(cc));
if (pixel_diff < diff.at(cc)) {
diff.at(cc) = pixel_diff;
closest.at(cc) = {x, y};
}
}
}
}
return closest;
}
template <uint32_t X, uint32_t Y, uint32_t D, uint32_t A, uint32_t P>
class PiRaw {
public:
PiRaw(std::unique_ptr<Image<X, Y>>);
static PiRaw FromJpeg(const std::string_view& jpeg);
static PiRaw FromRaw(const std::string_view& raw);
std::string ToPng();
const Image<X, Y>& GetImage();
private:
static constexpr uint32_t kJpegHeaderBytes = 32768;
static constexpr const char* kJpegHeaderMagic = "BRCM";
@@ -53,13 +137,13 @@ class PiRaw {
static Chunk GetChunk(const std::string_view& raw, const uint32_t x_chunk, const uint32_t y);
static Pixel CombineRaw(uint32_t y0x0, uint32_t y0x1, uint32_t y1x0, uint32_t y1x1);
std::unique_ptr<Image> image_;
std::unique_ptr<Image<X, Y>> image_;
};
typedef PiRaw<3280,2464,10,16,2> PiRaw2;
template <uint32_t X, uint32_t Y, uint32_t D, uint32_t A, uint32_t P>
PiRaw<X,Y,D,A,P>::PiRaw(std::unique_ptr<Image> image)
PiRaw<X,Y,D,A,P>::PiRaw(std::unique_ptr<Image<X, Y>> image)
: image_(std::move(image)) {}
template <uint32_t X, uint32_t Y, uint32_t D, uint32_t A, uint32_t P>
@@ -77,7 +161,7 @@ PiRaw<X,Y,D,A,P> PiRaw<X,Y,D,A,P>::FromRaw(const std::string_view& raw) {
assert(raw.size() == GetRawBytes());
auto image = std::make_unique<Image>();
auto image = std::make_unique<Image<X, Y>>();
for (uint32_t y = 0, out_y = 0; y < Y; y += 2, ++out_y) {
for (uint32_t x_chunk = 0, out_x = 0; x_chunk < X / kPixelsPerChunk; ++x_chunk, out_x += kPixelsPerChunk / 2) {
@@ -136,7 +220,7 @@ typename PiRaw<X,Y,D,A,P>::Chunk PiRaw<X,Y,D,A,P>::GetChunk(const std::string_vi
}
template <uint32_t X, uint32_t Y, uint32_t D, uint32_t A, uint32_t P>
typename PiRaw<X,Y,D,A,P>::Pixel PiRaw<X,Y,D,A,P>::CombineRaw(uint32_t y0x0, uint32_t y0x1, uint32_t y1x0, uint32_t y1x1) {
Pixel PiRaw<X,Y,D,A,P>::CombineRaw(uint32_t y0x0, uint32_t y0x1, uint32_t y1x0, uint32_t y1x1) {
// Function is bit layout specific
Pixel ret;
ret.r = y1x1;
@@ -182,6 +266,10 @@ std::string PiRaw<X,Y,D,A,P>::ToPng() {
return ret;
}
template <uint32_t X, uint32_t Y, uint32_t D, uint32_t A, uint32_t P>
const Image<X, Y>& PiRaw<X,Y,D,A,P>::GetImage() {
return *image_;
}
std::string ReadFile(const std::string& filename) {
int fh = open(filename.c_str(), O_RDONLY);
@@ -199,7 +287,6 @@ std::string ReadFile(const std::string& filename) {
return contents;
}
void WriteFile(const std::string& filename, const std::string& contents) {
int fh = open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644);
assert(fh != -1);
@@ -210,5 +297,9 @@ void WriteFile(const std::string& filename, const std::string& contents) {
int main() {
auto raw = PiRaw2::FromJpeg(ReadFile("test.jpg"));
auto closest = raw.GetImage().ColorCheckerClosest();
for (uint32_t cc = 0; cc < kNumColorChecker; ++cc) {
std::cout << cc << ": " << closest.at(cc) << std::endl;
}
WriteFile("test.png", raw.ToPng());
}