//---------------------------------------------------------------------------- // Anti-Grain Geometry (AGG) - Version 2.5 // A high quality rendering engine for C++ // Copyright (C) 2002-2006 Maxim Shemanarev // Contact: mcseem@antigrain.com // mcseemagg@yahoo.com // http://antigrain.com // // AGG is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License // as published by the Free Software Foundation; either version 2 // of the License, or (at your option) any later version. // // AGG is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with AGG; if not, write to the Free Software // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, // MA 02110-1301, USA. //---------------------------------------------------------------------------- #ifndef AGG_IMAGE_FILTERS_INCLUDED #define AGG_IMAGE_FILTERS_INCLUDED #include "agg_array.h" #include "agg_math.h" namespace agg { // See Implementation agg_image_filters.cpp enum image_filter_scale_e { image_filter_shift = 14, //----image_filter_shift image_filter_scale = 1 << image_filter_shift, //----image_filter_scale image_filter_mask = image_filter_scale - 1 //----image_filter_mask }; enum image_subpixel_scale_e { image_subpixel_shift = 8, //----image_subpixel_shift image_subpixel_scale = 1 << image_subpixel_shift, //----image_subpixel_scale image_subpixel_mask = image_subpixel_scale - 1 //----image_subpixel_mask }; //-----------------------------------------------------image_filter_lut class image_filter_lut { public: template<class FilterF> void calculate(const FilterF& filter, bool normalization=true) { double r = filter.radius(); realloc_lut(r); unsigned i; unsigned pivot = diameter() << (image_subpixel_shift - 1); for(i = 0; i < pivot; i++) { double x = double(i) / double(image_subpixel_scale); double y = filter.calc_weight(x); m_weight_array[pivot + i] = m_weight_array[pivot - i] = (int16)iround(y * image_filter_scale); } unsigned end = (diameter() << image_subpixel_shift) - 1; m_weight_array[0] = m_weight_array[end]; if(normalization) { normalize(); } } image_filter_lut() : m_radius(0), m_diameter(0), m_start(0) {} template<class FilterF> image_filter_lut(const FilterF& filter, bool normalization=true) { calculate(filter, normalization); } double radius() const { return m_radius; } unsigned diameter() const { return m_diameter; } int start() const { return m_start; } const int16* weight_array() const { return &m_weight_array[0]; } void normalize(); private: void realloc_lut(double radius); image_filter_lut(const image_filter_lut&); const image_filter_lut& operator = (const image_filter_lut&); double m_radius; unsigned m_diameter; int m_start; pod_array<int16> m_weight_array; }; //--------------------------------------------------------image_filter template<class FilterF> class image_filter : public image_filter_lut { public: image_filter() { calculate(m_filter_function); } private: FilterF m_filter_function; }; //-----------------------------------------------image_filter_bilinear struct image_filter_bilinear { static double radius() { return 1.0; } static double calc_weight(double x) { return 1.0 - x; } }; //-----------------------------------------------image_filter_hanning struct image_filter_hanning { static double radius() { return 1.0; } static double calc_weight(double x) { return 0.5 + 0.5 * cos(pi * x); } }; //-----------------------------------------------image_filter_hamming struct image_filter_hamming { static double radius() { return 1.0; } static double calc_weight(double x) { return 0.54 + 0.46 * cos(pi * x); } }; //-----------------------------------------------image_filter_hermite struct image_filter_hermite { static double radius() { return 1.0; } static double calc_weight(double x) { return (2.0 * x - 3.0) * x * x + 1.0; } }; //------------------------------------------------image_filter_quadric struct image_filter_quadric { static double radius() { return 1.5; } static double calc_weight(double x) { double t; if(x < 0.5) return 0.75 - x * x; if(x < 1.5) {t = x - 1.5; return 0.5 * t * t;} return 0.0; } }; //------------------------------------------------image_filter_bicubic class image_filter_bicubic { static double pow3(double x) { return (x <= 0.0) ? 0.0 : x * x * x; } public: static double radius() { return 2.0; } static double calc_weight(double x) { return (1.0/6.0) * (pow3(x + 2) - 4 * pow3(x + 1) + 6 * pow3(x) - 4 * pow3(x - 1)); } }; //-------------------------------------------------image_filter_kaiser class image_filter_kaiser { double a; double i0a; double epsilon; public: image_filter_kaiser(double b = 6.33) : a(b), epsilon(1e-12) { i0a = 1.0 / bessel_i0(b); } static double radius() { return 1.0; } double calc_weight(double x) const { return bessel_i0(a * sqrt(1. - x * x)) * i0a; } private: double bessel_i0(double x) const { int i; double sum, y, t; sum = 1.; y = x * x / 4.; t = y; for(i = 2; t > epsilon; i++) { sum += t; t *= (double)y / (i * i); } return sum; } }; //----------------------------------------------image_filter_catrom struct image_filter_catrom { static double radius() { return 2.0; } static double calc_weight(double x) { if(x < 1.0) return 0.5 * (2.0 + x * x * (-5.0 + x * 3.0)); if(x < 2.0) return 0.5 * (4.0 + x * (-8.0 + x * (5.0 - x))); return 0.; } }; //---------------------------------------------image_filter_mitchell class image_filter_mitchell { double p0, p2, p3; double q0, q1, q2, q3; public: image_filter_mitchell(double b = 1.0/3.0, double c = 1.0/3.0) : p0((6.0 - 2.0 * b) / 6.0), p2((-18.0 + 12.0 * b + 6.0 * c) / 6.0), p3((12.0 - 9.0 * b - 6.0 * c) / 6.0), q0((8.0 * b + 24.0 * c) / 6.0), q1((-12.0 * b - 48.0 * c) / 6.0), q2((6.0 * b + 30.0 * c) / 6.0), q3((-b - 6.0 * c) / 6.0) {} static double radius() { return 2.0; } double calc_weight(double x) const { if(x < 1.0) return p0 + x * x * (p2 + x * p3); if(x < 2.0) return q0 + x * (q1 + x * (q2 + x * q3)); return 0.0; } }; //----------------------------------------------image_filter_spline16 struct image_filter_spline16 { static double radius() { return 2.0; } static double calc_weight(double x) { if(x < 1.0) { return ((x - 9.0/5.0 ) * x - 1.0/5.0 ) * x + 1.0; } return ((-1.0/3.0 * (x-1) + 4.0/5.0) * (x-1) - 7.0/15.0 ) * (x-1); } }; //---------------------------------------------image_filter_spline36 struct image_filter_spline36 { static double radius() { return 3.0; } static double calc_weight(double x) { if(x < 1.0) { return ((13.0/11.0 * x - 453.0/209.0) * x - 3.0/209.0) * x + 1.0; } if(x < 2.0) { return ((-6.0/11.0 * (x-1) + 270.0/209.0) * (x-1) - 156.0/ 209.0) * (x-1); } return ((1.0/11.0 * (x-2) - 45.0/209.0) * (x-2) + 26.0/209.0) * (x-2); } }; //----------------------------------------------image_filter_gaussian struct image_filter_gaussian { static double radius() { return 2.0; } static double calc_weight(double x) { return exp(-2.0 * x * x) * sqrt(2.0 / pi); } }; //------------------------------------------------image_filter_bessel struct image_filter_bessel { static double radius() { return 3.2383; } static double calc_weight(double x) { return (x == 0.0) ? pi / 4.0 : besj(pi * x, 1) / (2.0 * x); } }; //-------------------------------------------------image_filter_sinc class image_filter_sinc { public: image_filter_sinc(double r) : m_radius(r < 2.0 ? 2.0 : r) {} double radius() const { return m_radius; } double calc_weight(double x) const { if(x == 0.0) return 1.0; x *= pi; return sin(x) / x; } private: double m_radius; }; //-----------------------------------------------image_filter_lanczos class image_filter_lanczos { public: image_filter_lanczos(double r) : m_radius(r < 2.0 ? 2.0 : r) {} double radius() const { return m_radius; } double calc_weight(double x) const { if(x == 0.0) return 1.0; if(x > m_radius) return 0.0; x *= pi; double xr = x / m_radius; return (sin(x) / x) * (sin(xr) / xr); } private: double m_radius; }; //----------------------------------------------image_filter_blackman class image_filter_blackman { public: image_filter_blackman(double r) : m_radius(r < 2.0 ? 2.0 : r) {} double radius() const { return m_radius; } double calc_weight(double x) const { if(x == 0.0) return 1.0; if(x > m_radius) return 0.0; x *= pi; double xr = x / m_radius; return (sin(x) / x) * (0.42 + 0.5*cos(xr) + 0.08*cos(2*xr)); } private: double m_radius; }; //------------------------------------------------image_filter_sinc36 class image_filter_sinc36 : public image_filter_sinc { public: image_filter_sinc36() : image_filter_sinc(3.0){} }; //------------------------------------------------image_filter_sinc64 class image_filter_sinc64 : public image_filter_sinc { public: image_filter_sinc64() : image_filter_sinc(4.0){} }; //-----------------------------------------------image_filter_sinc100 class image_filter_sinc100 : public image_filter_sinc { public: image_filter_sinc100() : image_filter_sinc(5.0){} }; //-----------------------------------------------image_filter_sinc144 class image_filter_sinc144 : public image_filter_sinc { public: image_filter_sinc144() : image_filter_sinc(6.0){} }; //-----------------------------------------------image_filter_sinc196 class image_filter_sinc196 : public image_filter_sinc { public: image_filter_sinc196() : image_filter_sinc(7.0){} }; //-----------------------------------------------image_filter_sinc256 class image_filter_sinc256 : public image_filter_sinc { public: image_filter_sinc256() : image_filter_sinc(8.0){} }; //---------------------------------------------image_filter_lanczos36 class image_filter_lanczos36 : public image_filter_lanczos { public: image_filter_lanczos36() : image_filter_lanczos(3.0){} }; //---------------------------------------------image_filter_lanczos64 class image_filter_lanczos64 : public image_filter_lanczos { public: image_filter_lanczos64() : image_filter_lanczos(4.0){} }; //--------------------------------------------image_filter_lanczos100 class image_filter_lanczos100 : public image_filter_lanczos { public: image_filter_lanczos100() : image_filter_lanczos(5.0){} }; //--------------------------------------------image_filter_lanczos144 class image_filter_lanczos144 : public image_filter_lanczos { public: image_filter_lanczos144() : image_filter_lanczos(6.0){} }; //--------------------------------------------image_filter_lanczos196 class image_filter_lanczos196 : public image_filter_lanczos { public: image_filter_lanczos196() : image_filter_lanczos(7.0){} }; //--------------------------------------------image_filter_lanczos256 class image_filter_lanczos256 : public image_filter_lanczos { public: image_filter_lanczos256() : image_filter_lanczos(8.0){} }; //--------------------------------------------image_filter_blackman36 class image_filter_blackman36 : public image_filter_blackman { public: image_filter_blackman36() : image_filter_blackman(3.0){} }; //--------------------------------------------image_filter_blackman64 class image_filter_blackman64 : public image_filter_blackman { public: image_filter_blackman64() : image_filter_blackman(4.0){} }; //-------------------------------------------image_filter_blackman100 class image_filter_blackman100 : public image_filter_blackman { public: image_filter_blackman100() : image_filter_blackman(5.0){} }; //-------------------------------------------image_filter_blackman144 class image_filter_blackman144 : public image_filter_blackman { public: image_filter_blackman144() : image_filter_blackman(6.0){} }; //-------------------------------------------image_filter_blackman196 class image_filter_blackman196 : public image_filter_blackman { public: image_filter_blackman196() : image_filter_blackman(7.0){} }; //-------------------------------------------image_filter_blackman256 class image_filter_blackman256 : public image_filter_blackman { public: image_filter_blackman256() : image_filter_blackman(8.0){} }; } #endif |