// Copyright (C) 2006 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_PIXEl_
#define DLIB_PIXEl_
#include <iostream>
#include "serialize.h"
#include <cmath>
#include "algs.h"
#include "uintn.h"
#include <limits>
#include <complex>
#include "enable_if.h"
namespace dlib
{
// ----------------------------------------------------------------------------------------
/*!
This file contains definitions of pixel objects and related classes and
functionality.
!*/
// ----------------------------------------------------------------------------------------
template <typename T>
struct pixel_traits;
/*!
WHAT THIS OBJECT REPRESENTS
As the name implies, this is a traits class for pixel types.
It defines the properties of a pixel.
This traits class will define the following public static members:
- bool grayscale
- bool rgb
- bool rgb_alpha
- bool hsi
- bool lab
- bool has_alpha
- long num
- basic_pixel_type
- basic_pixel_type min()
- basic_pixel_type max()
- is_unsigned
The above public constants are subject to the following constraints:
- only one of grayscale, rgb, rgb_alpha, hsi or lab is true
- if (rgb == true) then
- The type T will be a struct with 3 public members of type
unsigned char named "red" "green" and "blue".
- This type of pixel represents the RGB color space.
- num == 3
- has_alpha == false
- basic_pixel_type == unsigned char
- min() == 0
- max() == 255
- is_unsigned == true
- if (rgb_alpha == true) then
- The type T will be a struct with 4 public members of type
unsigned char named "red" "green" "blue" and "alpha".
- This type of pixel represents the RGB color space with
an alpha channel where an alpha of 0 represents a pixel
that is totally transparent and 255 represents a pixel
with maximum opacity.
- num == 4
- has_alpha == true
- basic_pixel_type == unsigned char
- min() == 0
- max() == 255
- is_unsigned == true
- else if (hsi == true) then
- The type T will be a struct with 3 public members of type
unsigned char named "h" "s" and "i".
- This type of pixel represents the HSI color space.
- num == 3
- has_alpha == false
- basic_pixel_type == unsigned char
- min() == 0
- max() == 255
- is_unsigned == true
- else if (lab == true) then
- The type T will be a struct with 3 public members of type
unsigned char named "l" "a" and "b".
- This type of pixel represents the Lab color space.
- num == 3
- has_alpha == false
- basic_pixel_type == unsigned char
- min() == 0
- max() == 255
- is_unsigned == true
- else
- grayscale == true
- This type of pixel represents a grayscale color space. T
will be some kind of basic scalar type such as unsigned int.
- num == 1
- has_alpha == false
- basic_pixel_type == T
- min() == the minimum obtainable value of objects of type T
- max() == the maximum obtainable value of objects of type T
- is_unsigned is true if min() == 0 and false otherwise
!*/
// ----------------------------------------------------------------------------------------
struct rgb_pixel
{
/*!
WHAT THIS OBJECT REPRESENTS
This is a simple struct that represents an RGB colored graphical pixel.
!*/
rgb_pixel (
) {}
rgb_pixel (
unsigned char red_,
unsigned char green_,
unsigned char blue_
) : red(red_), green(green_), blue(blue_) {}
unsigned char red;
unsigned char green;
unsigned char blue;
};
// ----------------------------------------------------------------------------------------
struct bgr_pixel
{
/*!
WHAT THIS OBJECT REPRESENTS
This is a simple struct that represents an BGR colored graphical pixel.
(the reason it exists in addition to the rgb_pixel is so you can lay
it down on top of a memory region that organizes its color data in the
BGR format and still be able to read it)
!*/
bgr_pixel (
) {}
bgr_pixel (
unsigned char blue_,
unsigned char green_,
unsigned char red_
) : blue(blue_), green(green_), red(red_) {}
unsigned char blue;
unsigned char green;
unsigned char red;
};
// ----------------------------------------------------------------------------------------
struct rgb_alpha_pixel
{
/*!
WHAT THIS OBJECT REPRESENTS
This is a simple struct that represents an RGB colored graphical pixel
with an alpha channel.
!*/
rgb_alpha_pixel (
) {}
rgb_alpha_pixel (
unsigned char red_,
unsigned char green_,
unsigned char blue_,
unsigned char alpha_
) : red(red_), green(green_), blue(blue_), alpha(alpha_) {}
unsigned char red;
unsigned char green;
unsigned char blue;
unsigned char alpha;
};
// ----------------------------------------------------------------------------------------
struct hsi_pixel
{
/*!
WHAT THIS OBJECT REPRESENTS
This is a simple struct that represents an HSI colored graphical pixel.
!*/
hsi_pixel (
) {}
hsi_pixel (
unsigned char h_,
unsigned char s_,
unsigned char i_
) : h(h_), s(s_), i(i_) {}
unsigned char h;
unsigned char s;
unsigned char i;
};
// ----------------------------------------------------------------------------------------
struct lab_pixel
{
/*!
WHAT THIS OBJECT REPRESENTS
This is a simple struct that represents an Lab colored graphical pixel.
!*/
lab_pixel (
) {}
lab_pixel (
unsigned char l_,
unsigned char a_,
unsigned char b_
) : l(l_), a(a_), b(b_) {}
unsigned char l;
unsigned char a;
unsigned char b;
};
// ----------------------------------------------------------------------------------------
template <
typename P1,
typename P2
>
inline void assign_pixel (
P1& dest,
const P2& src
);
/*!
requires
- pixel_traits<P1> must be defined
- pixel_traits<P2> must be defined
ensures
- if (P1 and P2 are the same type of pixel) then
- simply copies the value of src into dest. In other words,
dest will be identical to src after this function returns.
- else if (P1 and P2 are not the same type of pixel) then
- assigns pixel src to pixel dest and does any necessary color space
conversions.
- When converting from a grayscale color space with more than 255 values the
pixel intensity is saturated at pixel_traits<P1>::max() or pixel_traits<P1>::min()
as appropriate.
- if (the dest pixel has an alpha channel and the src pixel doesn't) then
- #dest.alpha == 255
- else if (the src pixel has an alpha channel but the dest pixel doesn't) then
- #dest == the original dest value blended with the src value according
to the alpha channel in src.
(i.e. #dest == src*(alpha/255) + dest*(1-alpha/255))
!*/
// ----------------------------------------------------------------------------------------
template <
typename P
>
inline typename pixel_traits<P>::basic_pixel_type get_pixel_intensity (
const P& src
);
/*!
requires
- pixel_traits<P> must be defined
ensures
- if (pixel_traits<P>::grayscale == true) then
- returns src
- else
- converts src to grayscale and returns the resulting value.
!*/
// ----------------------------------------------------------------------------------------
template <
typename P,
typename T
>
inline void assign_pixel_intensity (
P& dest,
const T& new_intensity
);
/*!
requires
- pixel_traits<P> must be defined
- pixel_traits<T> must be defined
ensures
- This function changes the intensity of the dest pixel. So if the pixel in
question is a grayscale pixel then it simply assigns that pixel with the
value of get_pixel_intensity(new_intensity). However, if the pixel is not
a grayscale pixel then it converts the pixel to the HSI color space and sets
the I channel to the given intensity and then converts this HSI value back to
the original pixel's color space.
- Note that we don't necessarily have #get_pixel_intensity(dest) == get_pixel_intensity(new_intensity)
due to vagaries of how converting to and from HSI works out.
- if (the dest pixel has an alpha channel) then
- #dest.alpha == dest.alpha
!*/
// ----------------------------------------------------------------------------------------
inline void serialize (
const rgb_pixel& item,
std::ostream& out
);
/*!
provides serialization support for the rgb_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void deserialize (
rgb_pixel& item,
std::istream& in
);
/*!
provides deserialization support for the rgb_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void serialize (
const bgr_pixel& item,
std::ostream& out
);
/*!
provides serialization support for the bgr_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void deserialize (
bgr_pixel& item,
std::istream& in
);
/*!
provides deserialization support for the bgr_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void serialize (
const rgb_alpha_pixel& item,
std::ostream& out
);
/*!
provides serialization support for the rgb_alpha_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void deserialize (
rgb_alpha_pixel& item,
std::istream& in
);
/*!
provides deserialization support for the rgb_alpha_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void serialize (
const hsi_pixel& item,
std::ostream& out
);
/*!
provides serialization support for the hsi_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void serialize (
const lab_pixel& item,
std::ostream& out
);
/*!
provides serialization support for the lab_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void deserialize (
hsi_pixel& item,
std::istream& in
);
/*!
provides deserialization support for the hsi_pixel struct
!*/
// ----------------------------------------------------------------------------------------
inline void deserialize (
lab_pixel& item,
std::istream& in
);
/*!
provides deserialization support for the lab_pixel struct
!*/
// ----------------------------------------------------------------------------------------
template <>
struct pixel_traits<rgb_pixel>
{
constexpr static bool rgb = true;
constexpr static bool rgb_alpha = false;
constexpr static bool grayscale = false;
constexpr static bool hsi = false;
constexpr static bool lab = false;
enum { num = 3};
typedef unsigned char basic_pixel_type;
static basic_pixel_type min() { return 0;}
static basic_pixel_type max() { return 255;}
constexpr static bool is_unsigned = true;
constexpr static bool has_alpha = false;
};
// ----------------------------------------------------------------------------------------
template <>
struct pixel_traits<bgr_pixel>
{
constexpr static bool rgb = true;
constexpr static bool rgb_alpha = false;
constexpr static bool grayscale = false;
constexpr static bool hsi = false;
constexpr static bool lab = false;
constexpr static long num = 3;
typedef unsigned char basic_pixel_type;
static basic_pixel_type min() { return 0;}
static basic_pixel_type max() { return 255;}
constexpr static bool is_unsigned = true;
constexpr static bool has_alpha = false;
};
// ----------------------------------------------------------------------------------------
template <>
struct pixel_traits<rgb_alpha_pixel>
{
constexpr static bool rgb = false;
constexpr static bool rgb_alpha = true;
constexpr static bool grayscale = false;
constexpr static bool hsi = false;
constexpr static bool lab = false;
constexpr static long num = 4;
typedef unsigned char basic_pixel_type;
static basic_pixel_type min() { return 0;}
static basic_pixel_type max() { return 255;}
constexpr static bool is_unsigned = true;
constexpr static bool has_alpha = true;
};
// ----------------------------------------------------------------------------------------
template <>
struct pixel_traits<hsi_pixel>
{
constexpr static bool rgb = false;
constexpr static bool rgb_alpha = false;
constexpr static bool grayscale = false;
constexpr static bool hsi = true;
constexpr static bool lab = false;
constexpr static long num = 3;
typedef unsigned char basic_pixel_type;
static basic_pixel_type min() { return 0;}
static basic_pixel_type max() { return 255;}
constexpr static bool is_unsigned = true;
constexpr static bool has_alpha = false;
};
// ----------------------------------------------------------------------------------------
template <>
struct pixel_traits<lab_pixel>
{
constexpr static bool rgb = false;
constexpr static bool rgb_alpha = false;
constexpr static bool grayscale = false;
constexpr static bool hsi = false;
constexpr static bool lab = true;
constexpr static long num = 3;
typedef unsigned char basic_pixel_type;
static basic_pixel_type min() { return 0;}
static basic_pixel_type max() { return 255;}
constexpr static bool is_unsigned = true;
constexpr static bool has_alpha = false;
};
// ----------------------------------------------------------------------------------------
template <typename T>
struct grayscale_pixel_traits
{
constexpr static bool rgb = false;
constexpr static bool rgb_alpha = false;
constexpr static bool grayscale = true;
constexpr static bool hsi = false;
constexpr static bool lab = false;
constexpr static long num = 1;
constexpr static bool has_alpha = false;
typedef T basic_pixel_type;
static basic_pixel_type min() { return std::numeric_limits<T>::min();}
static basic_pixel_type max() { return std::numeric_limits<T>::max();}
constexpr static bool is_unsigned = is_unsigned_type<T>::value;
};
template <> struct pixel_traits<unsigned char> : public grayscale_pixel_traits<unsigned char> {};
template <> struct pixel_traits<unsigned short> : public grayscale_pixel_traits<unsigned short> {};
template <> struct pixel_traits<unsigned int> : public grayscale_pixel_traits<unsigned int> {};
template <> struct pixel_traits<unsigned long> : public grayscale_pixel_traits<unsigned long> {};
template <> struct pixel_traits<char> : public grayscale_pixel_traits<char> {};
template <> struct pixel_traits<signed char> : public grayscale_pixel_traits<signed char> {};
template <> struct pixel_traits<short> : public grayscale_pixel_traits<short> {};
template <> struct pixel_traits<int> : public grayscale_pixel_traits<int> {};
template <> struct pixel_traits<long> : public grayscale_pixel_traits<long> {};
template <> struct pixel_traits<int64> : public grayscale_pixel_traits<int64> {};
template <> struct pixel_traits<uint64> : public grayscale_pixel_traits<uint64> {};
// ----------------------------------------------------------------------------------------
template <typename T>
struct float_grayscale_pixel_traits
{
constexpr static bool rgb = false;
constexpr static bool rgb_alpha = false;
constexpr static bool grayscale = true;
constexpr static bool hsi = false;
constexpr static bool lab = false;
constexpr static long num = 1;
constexpr static bool has_alpha = false;
typedef T basic_pixel_type;
static basic_pixel_type min() { return -std::numeric_limits<T>::max();}
static basic_pixel_type max() { return std::numeric_limits<T>::max();}
constexpr static bool is_unsigned = false;
};
template <> struct pixel_traits<float> : public float_grayscale_pixel_traits<float> {};
template <> struct pixel_traits<double> : public float_grayscale_pixel_traits<double> {};
template <> struct pixel_traits<long double> : public float_grayscale_pixel_traits<long double> {};
// These are here mainly so you can easily copy images into complex arrays. This is
// useful when you want to do a FFT on an image or some similar operation.
template <> struct pixel_traits<std::complex<float> > : public float_grayscale_pixel_traits<float> {};
template <> struct pixel_traits<std::complex<double> > : public float_grayscale_pixel_traits<double> {};
template <> struct pixel_traits<std::complex<long double> > : public float_grayscale_pixel_traits<long double> {};
// ----------------------------------------------------------------------------------------
// The following is a bunch of conversion stuff for the assign_pixel function.
namespace assign_pixel_helpers
{
// -----------------------------
// all the same kind
template < typename P >
typename enable_if_c<pixel_traits<P>::grayscale>::type
assign(P& dest, const P& src)
{
dest = src;
}
// -----------------------------
template <typename T>
typename unsigned_type<T>::type make_unsigned (
const T& val
) { return static_cast<typename unsigned_type<T>::type>(val); }
inline float make_unsigned(const float& val) { return val; }
inline double make_unsigned(const double& val) { return val; }
inline long double make_unsigned(const long double& val) { return val; }
template <typename T, typename P>
typename enable_if_c<pixel_traits<T>::is_unsigned == pixel_traits<P>::is_unsigned, bool>::type less_or_equal_to_max (
const P& p
)
/*!
ensures
- returns true if p is <= max value of T
!*/
{
return p <= pixel_traits<T>::max();
}
template <typename T, typename P>
typename enable_if_c<pixel_traits<T>::is_unsigned && !pixel_traits<P>::is_unsigned, bool>::type less_or_equal_to_max (
const P& p
)
{
if (p <= 0)
return true;
else if (make_unsigned(p) <= pixel_traits<T>::max())
return true;
else
return false;
}
template <typename T, typename P>
typename enable_if_c<!pixel_traits<T>::is_unsigned && pixel_traits<P>::is_unsigned, bool>::type less_or_equal_to_max (
const P& p
)
{
return p <= make_unsigned(pixel_traits<T>::max());
}
// -----------------------------
template <typename T, typename P>
typename enable_if_c<pixel_traits<P>::is_unsigned, bool >::type greater_or_equal_to_min (
const P&
) { return true; }
/*!
ensures
- returns true if p is >= min value of T
!*/
template <typename T, typename P>
typename enable_if_c<!pixel_traits<P>::is_unsigned && pixel_traits<T>::is_unsigned, bool >::type greater_or_equal_to_min (
const P& p
)
{
return p >= 0;
}
template <typename T, typename P>
typename enable_if_c<!pixel_traits<P>::is_unsigned && !pixel_traits<T>::is_unsigned, bool >::type greater_or_equal_to_min (
const P& p
)
{
return p >= pixel_traits<T>::min();
}
// -----------------------------
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::grayscale && pixel_traits<P2>::grayscale>::type
assign(P1& dest, const P2& src)
{
/*
The reason for these weird comparison functions is to avoid getting compiler
warnings about comparing signed types to unsigned and stuff like that.
*/
if (less_or_equal_to_max<P1>(src))
if (greater_or_equal_to_min<P1>(src))
dest = static_cast<P1>(src);
else
dest = pixel_traits<P1>::min();
else
dest = pixel_traits<P1>::max();
}
// -----------------------------
// -----------------------------
// -----------------------------
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb && pixel_traits<P2>::rgb>::type
assign(P1& dest, const P2& src)
{
dest.red = src.red;
dest.green = src.green;
dest.blue = src.blue;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb_alpha && pixel_traits<P2>::rgb_alpha>::type
assign(P1& dest, const P2& src)
{
dest.red = src.red;
dest.green = src.green;
dest.blue = src.blue;
dest.alpha = src.alpha;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::hsi && pixel_traits<P2>::hsi>::type
assign(P1& dest, const P2& src)
{
dest.h = src.h;
dest.s = src.s;
dest.i = src.i;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::lab && pixel_traits<P2>::lab>::type
assign(P1& dest, const P2& src)
{
dest.l = src.l;
dest.a = src.a;
dest.b = src.b;
}
// -----------------------------
// dest is a grayscale
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::grayscale && pixel_traits<P2>::rgb>::type
assign(P1& dest, const P2& src)
{
const unsigned int temp = ((static_cast<unsigned int>(src.red) +
static_cast<unsigned int>(src.green) +
static_cast<unsigned int>(src.blue))/3);
assign_pixel(dest, temp);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::grayscale && pixel_traits<P2>::rgb_alpha>::type
assign(P1& dest, const P2& src)
{
const unsigned char avg = static_cast<unsigned char>((static_cast<unsigned int>(src.red) +
static_cast<unsigned int>(src.green) +
static_cast<unsigned int>(src.blue))/3);
if (src.alpha == 255)
{
assign_pixel(dest, avg);
}
else
{
// perform this assignment using fixed point arithmetic:
// dest = src*(alpha/255) + dest*(1 - alpha/255);
// dest = src*(alpha/255) + dest*1 - dest*(alpha/255);
// dest = dest*1 + src*(alpha/255) - dest*(alpha/255);
// dest = dest*1 + (src - dest)*(alpha/255);
// dest += (src - dest)*(alpha/255);
int temp = avg;
// copy dest into dest_copy using assign_pixel to avoid potential
// warnings about implicit float to int warnings.
int dest_copy;
assign_pixel(dest_copy, dest);
temp -= dest_copy;
temp *= src.alpha;
temp /= 255;
assign_pixel(dest, temp+dest_copy);
}
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::grayscale && pixel_traits<P2>::hsi>::type
assign(P1& dest, const P2& src)
{
assign_pixel(dest, src.i);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::grayscale && pixel_traits<P2>::lab>::type
assign(P1& dest, const P2& src)
{
assign_pixel(dest, src.l);
}
// -----------------------------
struct HSL
{
double h;
double s;
double l;
};
struct COLOUR
{
double r;
double g;
double b;
};
/*
I found this excellent bit of code for dealing with HSL spaces at
http://local.wasp.uwa.edu.au/~pbourke/colour/hsl/
*/
/*
Calculate HSL from RGB
Hue is in degrees
Lightness is between 0 and 1
Saturation is between 0 and 1
*/
inline HSL RGB2HSL(COLOUR c1)
{
double themin,themax,delta;
HSL c2;
using namespace std;
themin = std::min(c1.r,std::min(c1.g,c1.b));
themax = std::max(c1.r,std::max(c1.g,c1.b));
delta = themax - themin;
c2.l = (themin + themax) / 2;
c2.s = 0;
if (c2.l > 0 && c2.l < 1)
c2.s = delta / (c2.l < 0.5 ? (2*c2.l) : (2-2*c2.l));
c2.h = 0;
if (delta > 0) {
if (themax == c1.r && themax != c1.g)
c2.h += (c1.g - c1.b) / delta;
if (themax == c1.g && themax != c1.b)
c2.h += (2 + (c1.b - c1.r) / delta);
if (themax == c1.b && themax != c1.r)
c2.h += (4 + (c1.r - c1.g) / delta);
c2.h *= 60;
}
return(c2);
}
/*
Calculate RGB from HSL, reverse of RGB2HSL()
Hue is in degrees
Lightness is between 0 and 1
Saturation is between 0 and 1
*/
inline COLOUR HSL2RGB(HSL c1)
{
COLOUR c2,sat,ctmp;
using namespace std;
if (c1.h < 120) {
sat.r = (120 - c1.h) / 60.0;
sat.g = c1.h / 60.0;
sat.b = 0;
} else if (c1.h < 240) {
sat.r = 0;
sat.g = (240 - c1.h) / 60.0;
sat.b = (c1.h - 120) / 60.0;
} else {
sat.r = (c1.h - 240) / 60.0;
sat.g = 0;
sat.b = (360 - c1.h) / 60.0;
}
sat.r = std::min(sat.r,1.0);
sat.g = std::min(sat.g,1.0);
sat.b = std::min(sat.b,1.0);
ctmp.r = 2 * c1.s * sat.r + (1 - c1.s);
ctmp.g = 2 * c1.s * sat.g + (1 - c1.s);
ctmp.b = 2 * c1.s * sat.b + (1 - c1.s);
if (c1.l < 0.5) {
c2.r = c1.l * ctmp.r;
c2.g = c1.l * ctmp.g;
c2.b = c1.l * ctmp.b;
} else {
c2.r = (1 - c1.l) * ctmp.r + 2 * c1.l - 1;
c2.g = (1 - c1.l) * ctmp.g + 2 * c1.l - 1;
c2.b = (1 - c1.l) * ctmp.b + 2 * c1.l - 1;
}
return(c2);
}
// -----------------------------
struct Lab
{
double l;
double a;
double b;
};
/*
Calculate Lab from RGB
L is between 0 and 100
a is between -128 and 127
b is between -128 and 127
RGB is between 0.0 and 1.0
*/
inline Lab RGB2Lab(COLOUR c1)
{
Lab c2;
using namespace std;
double var_R = c1.r;
double var_G = c1.g;
double var_B = c1.b;
if (var_R > 0.04045) {
var_R = pow(((var_R + 0.055) / 1.055), 2.4);
} else {
var_R = var_R / 12.92;
}
if (var_G > 0.04045) {
var_G = pow(((var_G + 0.055) / 1.055), 2.4);
} else {
var_G = var_G / 12.92;
}
if (var_B > 0.04045) {
var_B = pow(((var_B + 0.055) / 1.055), 2.4);
} else {
var_B = var_B / 12.92;
}
var_R = var_R * 100;
var_G = var_G * 100;
var_B = var_B * 100;
//Observer. = 2°, Illuminant = D65
double X = var_R * 0.4124 + var_G * 0.3576 + var_B * 0.1805;
double Y = var_R * 0.2126 + var_G * 0.7152 + var_B * 0.0722;
double Z = var_R * 0.0193 + var_G * 0.1192 + var_B * 0.9505;
double var_X = X / 95.047;
double var_Y = Y / 100.000;
double var_Z = Z / 108.883;
if (var_X > 0.008856) {
var_X = pow(var_X, (1.0 / 3));
}
else {
var_X = (7.787 * var_X) + (16.0 / 116);
}
if (var_Y > 0.008856) {
var_Y = pow(var_Y, (1.0 / 3));
}
else {
var_Y = (7.787 * var_Y) + (16.0 / 116);
}
if (var_Z > 0.008856) {
var_Z = pow(var_Z, (1.0 / 3));
}
else {
var_Z = (7.787 * var_Z) + (16.0 / 116);
}
//clamping
c2.l = max(0.0, (116.0 * var_Y) - 16);
c2.a = max(-128.0, min(127.0, 500.0 * (var_X - var_Y)));
c2.b = max(-128.0, min(127.0, 200.0 * (var_Y - var_Z)));
return c2;
}
/*
Calculate RGB from Lab, reverse of RGB2LAb()
L is between 0 and 100
a is between -128 and 127
b is between -128 and 127
RGB is between 0.0 and 1.0
*/
inline COLOUR Lab2RGB(Lab c1) {
COLOUR c2;
using namespace std;
double var_Y = (c1.l + 16) / 116.0;
double var_X = (c1.a / 500.0) + var_Y;
double var_Z = var_Y - (c1.b / 200);
if (pow(var_Y, 3) > 0.008856) {
var_Y = pow(var_Y, 3);
} else {
var_Y = (var_Y - 16.0 / 116) / 7.787;
}
if (pow(var_X, 3) > 0.008856) {
var_X = pow(var_X, 3);
} else {
var_X = (var_X - 16.0 / 116) / 7.787;
}
if (pow(var_Z, 3) > 0.008856) {
var_Z = pow(var_Z, 3);
} else {
var_Z = (var_Z - 16.0 / 116) / 7.787;
}
double X = var_X * 95.047;
double Y = var_Y * 100.000;
double Z = var_Z * 108.883;
var_X = X / 100.0;
var_Y = Y / 100.0;
var_Z = Z / 100.0;
double var_R = var_X * 3.2406 + var_Y * -1.5372 + var_Z * -0.4986;
double var_G = var_X * -0.9689 + var_Y * 1.8758 + var_Z * 0.0415;
double var_B = var_X * 0.0557 + var_Y * -0.2040 + var_Z * 1.0570;
if (var_R > 0.0031308) {
var_R = 1.055 * pow(var_R, (1 / 2.4)) - 0.055;
} else {
var_R = 12.92 * var_R;
}
if (var_G > 0.0031308) {
var_G = 1.055 * pow(var_G, (1 / 2.4)) - 0.055;
} else {
var_G = 12.92 * var_G;
}
if (var_B > 0.0031308) {
var_B = 1.055 * pow(var_B, (1 / 2.4)) - 0.055;
} else {
var_B = 12.92 * var_B;
}
// clamping
c2.r = max(0.0, min(1.0, var_R));
c2.g = max(0.0, min(1.0, var_G));
c2.b = max(0.0, min(1.0, var_B));
return (c2);
}
// -----------------------------
// dest is a color rgb_pixel
template < typename P1 >
typename enable_if_c<pixel_traits<P1>::rgb>::type
assign(P1& dest, const unsigned char& src)
{
dest.red = src;
dest.green = src;
dest.blue = src;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb && pixel_traits<P2>::grayscale>::type
assign(P1& dest, const P2& src)
{
unsigned char p;
assign_pixel(p, src);
dest.red = p;
dest.green = p;
dest.blue = p;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb && pixel_traits<P2>::rgb_alpha>::type
assign(P1& dest, const P2& src)
{
if (src.alpha == 255)
{
dest.red = src.red;
dest.green = src.green;
dest.blue = src.blue;
}
else
{
// perform this assignment using fixed point arithmetic:
// dest = src*(alpha/255) + dest*(1 - alpha/255);
// dest = src*(alpha/255) + dest*1 - dest*(alpha/255);
// dest = dest*1 + src*(alpha/255) - dest*(alpha/255);
// dest = dest*1 + (src - dest)*(alpha/255);
// dest += (src - dest)*(alpha/255);
unsigned int temp_r = src.red;
unsigned int temp_g = src.green;
unsigned int temp_b = src.blue;
temp_r -= dest.red;
temp_g -= dest.green;
temp_b -= dest.blue;
temp_r *= src.alpha;
temp_g *= src.alpha;
temp_b *= src.alpha;
temp_r >>= 8;
temp_g >>= 8;
temp_b >>= 8;
dest.red += static_cast<unsigned char>(temp_r&0xFF);
dest.green += static_cast<unsigned char>(temp_g&0xFF);
dest.blue += static_cast<unsigned char>(temp_b&0xFF);
}
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb && pixel_traits<P2>::hsi>::type
assign(P1& dest, const P2& src)
{
COLOUR c;
HSL h;
h.h = src.h;
h.h = h.h/255.0*360;
h.s = src.s/255.0;
h.l = src.i/255.0;
c = HSL2RGB(h);
dest.red = static_cast<unsigned char>(c.r*255.0 + 0.5);
dest.green = static_cast<unsigned char>(c.g*255.0 + 0.5);
dest.blue = static_cast<unsigned char>(c.b*255.0 + 0.5);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb && pixel_traits<P2>::lab>::type
assign(P1& dest, const P2& src)
{
COLOUR c;
Lab l;
l.l = (src.l/255.0)*100;
l.a = (src.a-128.0);
l.b = (src.b-128.0);
c = Lab2RGB(l);
dest.red = static_cast<unsigned char>(c.r*255.0 + 0.5);
dest.green = static_cast<unsigned char>(c.g*255.0 + 0.5);
dest.blue = static_cast<unsigned char>(c.b*255.0 + 0.5);
}
// -----------------------------
// dest is a color rgb_alpha_pixel
template < typename P1 >
typename enable_if_c<pixel_traits<P1>::rgb_alpha>::type
assign(P1& dest, const unsigned char& src)
{
dest.red = src;
dest.green = src;
dest.blue = src;
dest.alpha = 255;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb_alpha && pixel_traits<P2>::grayscale>::type
assign(P1& dest, const P2& src)
{
unsigned char p;
assign_pixel(p, src);
dest.red = p;
dest.green = p;
dest.blue = p;
dest.alpha = 255;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb_alpha && pixel_traits<P2>::rgb>::type
assign(P1& dest, const P2& src)
{
dest.red = src.red;
dest.green = src.green;
dest.blue = src.blue;
dest.alpha = 255;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb_alpha && pixel_traits<P2>::hsi>::type
assign(P1& dest, const P2& src)
{
COLOUR c;
HSL h;
h.h = src.h;
h.h = h.h/255.0*360;
h.s = src.s/255.0;
h.l = src.i/255.0;
c = HSL2RGB(h);
dest.red = static_cast<unsigned char>(c.r*255.0 + 0.5);
dest.green = static_cast<unsigned char>(c.g*255.0 + 0.5);
dest.blue = static_cast<unsigned char>(c.b*255.0 + 0.5);
dest.alpha = 255;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::rgb_alpha && pixel_traits<P2>::lab>::type
assign(P1& dest, const P2& src)
{
COLOUR c;
Lab l;
l.l = (src.l/255.0)*100;
l.a = (src.a-128.0);
l.b = (src.b-128.0);
c = Lab2RGB(l);
dest.red = static_cast<unsigned char>(c.r * 255 + 0.5);
dest.green = static_cast<unsigned char>(c.g * 255 + 0.5);
dest.blue = static_cast<unsigned char>(c.b * 255 + 0.5);
dest.alpha = 255;
}
// -----------------------------
// dest is an hsi pixel
template < typename P1>
typename enable_if_c<pixel_traits<P1>::hsi>::type
assign(P1& dest, const unsigned char& src)
{
dest.h = 0;
dest.s = 0;
dest.i = src;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::hsi && pixel_traits<P2>::grayscale>::type
assign(P1& dest, const P2& src)
{
dest.h = 0;
dest.s = 0;
assign_pixel(dest.i, src);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::hsi && pixel_traits<P2>::rgb>::type
assign(P1& dest, const P2& src)
{
COLOUR c1;
HSL c2;
c1.r = src.red/255.0;
c1.g = src.green/255.0;
c1.b = src.blue/255.0;
c2 = RGB2HSL(c1);
dest.h = static_cast<unsigned char>(c2.h/360.0*255.0 + 0.5);
dest.s = static_cast<unsigned char>(c2.s*255.0 + 0.5);
dest.i = static_cast<unsigned char>(c2.l*255.0 + 0.5);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::hsi && pixel_traits<P2>::rgb_alpha>::type
assign(P1& dest, const P2& src)
{
rgb_pixel temp;
// convert target hsi pixel to rgb
assign_pixel_helpers::assign(temp,dest);
// now assign the rgb_alpha value to our temp rgb pixel
assign_pixel_helpers::assign(temp,src);
// now we can just go assign the new rgb value to the
// hsi pixel
assign_pixel_helpers::assign(dest,temp);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::hsi && pixel_traits<P2>::lab>::type
assign(P1& dest, const P2& src)
{
rgb_pixel temp;
// convert lab value to our temp rgb pixel
assign_pixel_helpers::assign(temp,src);
// now we can just go assign the new rgb value to the
// hsi pixel
assign_pixel_helpers::assign(dest,temp);
}
// -----------------------------
// dest is an lab pixel
template < typename P1>
typename enable_if_c<pixel_traits<P1>::lab>::type
assign(P1& dest, const unsigned char& src)
{
dest.a = 128;
dest.b = 128;
dest.l = src;
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::lab && pixel_traits<P2>::grayscale>::type
assign(P1& dest, const P2& src)
{
dest.a = 128;
dest.b = 128;
assign_pixel(dest.l, src);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::lab && pixel_traits<P2>::rgb>::type
assign(P1& dest, const P2& src)
{
COLOUR c1;
Lab c2;
c1.r = src.red / 255.0;
c1.g = src.green / 255.0;
c1.b = src.blue / 255.0;
c2 = RGB2Lab(c1);
dest.l = static_cast<unsigned char>((c2.l / 100) * 255 + 0.5);
dest.a = static_cast<unsigned char>(c2.a + 128 + 0.5);
dest.b = static_cast<unsigned char>(c2.b + 128 + 0.5);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::lab && pixel_traits<P2>::rgb_alpha>::type
assign(P1& dest, const P2& src)
{
rgb_pixel temp;
// convert target lab pixel to rgb
assign_pixel_helpers::assign(temp,dest);
// now assign the rgb_alpha value to our temp rgb pixel
assign_pixel_helpers::assign(temp,src);
// now we can just go assign the new rgb value to the
// lab pixel
assign_pixel_helpers::assign(dest,temp);
}
template < typename P1, typename P2 >
typename enable_if_c<pixel_traits<P1>::lab && pixel_traits<P2>::hsi>::type
assign(P1& dest, const P2& src)
{
rgb_pixel temp;
// convert hsi value to our temp rgb pixel
assign_pixel_helpers::assign(temp,src);
// now we can just go assign the new rgb value to the
// lab pixel
assign_pixel_helpers::assign(dest,temp);
}
}
// -----------------------------
template < typename P1, typename P2 >
inline void assign_pixel (
P1& dest,
const P2& src
) { assign_pixel_helpers::assign(dest,src); }
// ----------------------------------------------------------------------------------------
template <
typename P,
typename T
>
inline typename enable_if_c<pixel_traits<P>::grayscale>::type assign_pixel_intensity_helper (
P& dest,
const T& new_intensity
)
{
assign_pixel(dest, new_intensity);
}
template <
typename P,
typename T
>
inline typename enable_if_c<pixel_traits<P>::grayscale == false &&
pixel_traits<P>::has_alpha>::type assign_pixel_intensity_helper (
P& dest,
const T& new_intensity
)
{
hsi_pixel p;
const unsigned long old_alpha = dest.alpha;
dest.alpha = 255;
rgb_pixel temp;
assign_pixel(temp, dest); // put dest into an rgb_pixel to avoid the somewhat complicated assign_pixel(hsi,rgb_alpha).
assign_pixel(p,temp);
assign_pixel(p.i, new_intensity);
assign_pixel(dest,p);
dest.alpha = old_alpha;
}
template <
typename P,
typename T
>
inline typename enable_if_c<pixel_traits<P>::grayscale == false &&
pixel_traits<P>::has_alpha == false>::type assign_pixel_intensity_helper (
P& dest,
const T& new_intensity
)
{
hsi_pixel p;
assign_pixel(p,dest);
assign_pixel(p.i, new_intensity);
assign_pixel(dest,p);
}
template <
typename P,
typename T
>
inline void assign_pixel_intensity (
P& dest,
const T& new_intensity
)
{
assign_pixel_intensity_helper(dest, new_intensity);
}
// ----------------------------------------------------------------------------------------
template <
typename P
>
inline typename enable_if_c<pixel_traits<P>::grayscale, P>::type get_pixel_intensity_helper (
const P& src
)
{
return src;
}
template <
typename P
>
inline typename enable_if_c<pixel_traits<P>::grayscale == false&&
pixel_traits<P>::has_alpha,
typename pixel_traits<P>::basic_pixel_type>::type get_pixel_intensity_helper (
const P& src
)
{
P temp = src;
temp.alpha = 255;
typename pixel_traits<P>::basic_pixel_type p;
assign_pixel(p,temp);
return p;
}
template <
typename P
>
inline typename enable_if_c<pixel_traits<P>::grayscale == false&&
pixel_traits<P>::has_alpha == false,
typename pixel_traits<P>::basic_pixel_type>::type get_pixel_intensity_helper (
const P& src
)
{
typename pixel_traits<P>::basic_pixel_type p;
assign_pixel(p,src);
return p;
}
template <
typename P
>
inline typename pixel_traits<P>::basic_pixel_type get_pixel_intensity (
const P& src
)
{
return get_pixel_intensity_helper(src);
}
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
inline void serialize (
const rgb_alpha_pixel& item,
std::ostream& out
)
{
try
{
serialize(item.red,out);
serialize(item.green,out);
serialize(item.blue,out);
serialize(item.alpha,out);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while serializing object of type rgb_alpha_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void deserialize (
rgb_alpha_pixel& item,
std::istream& in
)
{
try
{
deserialize(item.red,in);
deserialize(item.green,in);
deserialize(item.blue,in);
deserialize(item.alpha,in);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while deserializing object of type rgb_alpha_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void serialize (
const rgb_pixel& item,
std::ostream& out
)
{
try
{
serialize(item.red,out);
serialize(item.green,out);
serialize(item.blue,out);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while serializing object of type rgb_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void deserialize (
rgb_pixel& item,
std::istream& in
)
{
try
{
deserialize(item.red,in);
deserialize(item.green,in);
deserialize(item.blue,in);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while deserializing object of type rgb_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void serialize (
const bgr_pixel& item,
std::ostream& out
)
{
try
{
serialize(item.blue,out);
serialize(item.green,out);
serialize(item.red,out);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while serializing object of type bgr_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void deserialize (
bgr_pixel& item,
std::istream& in
)
{
try
{
deserialize(item.blue,in);
deserialize(item.green,in);
deserialize(item.red,in);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while deserializing object of type bgr_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void serialize (
const hsi_pixel& item,
std::ostream& out
)
{
try
{
serialize(item.h,out);
serialize(item.s,out);
serialize(item.i,out);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while serializing object of type hsi_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void deserialize (
hsi_pixel& item,
std::istream& in
)
{
try
{
deserialize(item.h,in);
deserialize(item.s,in);
deserialize(item.i,in);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while deserializing object of type hsi_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void serialize (
const lab_pixel& item,
std::ostream& out
)
{
try
{
serialize(item.l,out);
serialize(item.a,out);
serialize(item.b,out);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while serializing object of type lab_pixel");
}
}
// ----------------------------------------------------------------------------------------
inline void deserialize (
lab_pixel& item,
std::istream& in
)
{
try
{
deserialize(item.l,in);
deserialize(item.a,in);
deserialize(item.b,in);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while deserializing object of type lab_pixel");
}
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_PIXEl_