| 1 | // -*- mode: c++ -*- |
| 2 | |
| 3 | #ifndef __FACE_DETECTOR_MATH_UTILS_H__ |
| 4 | #define __FACE_DETECTOR_MATH_UTILS_H__ |
| 5 | |
| 6 | /**** |
| 7 | Copyright (c) 2020 Adrian I. Lam |
| 8 | |
| 9 | Permission is hereby granted, free of charge, to any person obtaining a copy |
| 10 | of this software and associated documentation files (the "Software"), to deal |
| 11 | in the Software without restriction, including without limitation the rights |
| 12 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 13 | copies of the Software, and to permit persons to whom the Software is |
| 14 | furnished to do so, subject to the following conditions: |
| 15 | |
| 16 | The above copyright notice and this permission notice shall be included in all |
| 17 | copies or substantial portions of the Software. |
| 18 | |
| 19 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 20 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 21 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 22 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 23 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 24 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 25 | SOFTWARE. |
| 26 | ****/ |
| 27 | |
| 28 | #include <cmath> |
| 29 | #include <initializer_list> |
| 30 | #include <dlib/image_processing.h> |
| 31 | |
| 32 | static const double PI = 3.14159265358979; |
| 33 | |
| 34 | template<class T> |
| 35 | static double avg(T container, double defaultValue = 0) |
| 36 | { |
| 37 | if (container.size() == 0) |
| 38 | { |
| 39 | return defaultValue; |
| 40 | } |
| 41 | |
| 42 | double sum = 0; |
| 43 | for (auto it = container.begin(); it != container.end(); ++it) |
| 44 | { |
| 45 | sum += *it; |
| 46 | } |
| 47 | return sum / container.size(); |
| 48 | } |
| 49 | |
| 50 | template<class... Args> |
| 51 | static dlib::point centroid(Args&... args) |
| 52 | { |
| 53 | std::size_t numArgs = sizeof...(args); |
| 54 | if (numArgs == 0) return dlib::point(0, 0); |
| 55 | |
| 56 | double sumX = 0, sumY = 0; |
| 57 | for (auto point : {args...}) |
| 58 | { |
| 59 | sumX += point.x(); |
| 60 | sumY += point.y(); |
| 61 | } |
| 62 | |
| 63 | return dlib::point(sumX / numArgs, sumY / numArgs); |
| 64 | } |
| 65 | |
| 66 | static inline double sq(double x) |
| 67 | { |
| 68 | return x * x; |
| 69 | } |
| 70 | |
| 71 | static double solveCosineRuleAngle(double opposite, |
| 72 | double adjacent1, |
| 73 | double adjacent2) |
| 74 | { |
| 75 | // c^2 = a^2 + b^2 - 2 a b cos(C) |
| 76 | double cosC = (sq(opposite) - sq(adjacent1) - sq(adjacent2)) / |
| 77 | (-2 * adjacent1 * adjacent2); |
| 78 | return std::acos(cosC); |
| 79 | } |
| 80 | |
| 81 | static inline double radToDeg(double rad) |
| 82 | { |
| 83 | return rad * 180 / PI; |
| 84 | } |
| 85 | |
| 86 | static inline double degToRad(double deg) |
| 87 | { |
| 88 | return deg * PI / 180; |
| 89 | } |
| 90 | |
| 91 | double dist(dlib::point& p1, dlib::point& p2) |
| 92 | { |
| 93 | double xDist = p1.x() - p2.x(); |
| 94 | double yDist = p1.y() - p2.y(); |
| 95 | |
| 96 | return std::hypot(xDist, yDist); |
| 97 | } |
| 98 | |
| 99 | /*! Scale linearly from 0 to 1 (both end-points inclusive) */ |
| 100 | double linearScale01(double num, double min, double max, |
| 101 | bool clipMin = true, bool clipMax = true) |
| 102 | { |
| 103 | if (num < min && clipMin) return 0.0; |
| 104 | if (num > max && clipMax) return 1.0; |
| 105 | return (num - min) / (max - min); |
| 106 | } |
| 107 | |
| 108 | #endif |