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42
43#ifndef __OPENCV_TEST_INTERPOLATION_HPP__
44#define __OPENCV_TEST_INTERPOLATION_HPP__
45
46#include "opencv2/core.hpp"
47#include "opencv2/imgproc.hpp"
48
49template <typename T> T readVal(const cv::Mat& src, int y, int x, int c, int border_type, cv::Scalar borderVal = cv::Scalar())
50{
51    if (border_type == cv::BORDER_CONSTANT)
52        return (y >= 0 && y < src.rows && x >= 0 && x < src.cols) ? src.at<T>(y, x * src.channels() + c) : cv::saturate_cast<T>(borderVal.val[c]);
53
54    return src.at<T>(cv::borderInterpolate(y, src.rows, border_type), cv::borderInterpolate(x, src.cols, border_type) * src.channels() + c);
55}
56
57template <typename T> struct NearestInterpolator
58{
59    static T getValue(const cv::Mat& src, float y, float x, int c, int border_type, cv::Scalar borderVal = cv::Scalar())
60    {
61        return readVal<T>(src, int(y), int(x), c, border_type, borderVal);
62    }
63};
64
65template <typename T> struct LinearInterpolator
66{
67    static T getValue(const cv::Mat& src, float y, float x, int c, int border_type, cv::Scalar borderVal = cv::Scalar())
68    {
69        int x1 = cvFloor(x);
70        int y1 = cvFloor(y);
71        int x2 = x1 + 1;
72        int y2 = y1 + 1;
73
74        float res = 0;
75
76        res += readVal<T>(src, y1, x1, c, border_type, borderVal) * ((x2 - x) * (y2 - y));
77        res += readVal<T>(src, y1, x2, c, border_type, borderVal) * ((x - x1) * (y2 - y));
78        res += readVal<T>(src, y2, x1, c, border_type, borderVal) * ((x2 - x) * (y - y1));
79        res += readVal<T>(src, y2, x2, c, border_type, borderVal) * ((x - x1) * (y - y1));
80
81        return cv::saturate_cast<T>(res);
82    }
83};
84
85template <typename T> struct CubicInterpolator
86{
87    static float bicubicCoeff(float x_)
88    {
89        float x = fabsf(x_);
90        if (x <= 1.0f)
91        {
92            return x * x * (1.5f * x - 2.5f) + 1.0f;
93        }
94        else if (x < 2.0f)
95        {
96            return x * (x * (-0.5f * x + 2.5f) - 4.0f) + 2.0f;
97        }
98        else
99        {
100            return 0.0f;
101        }
102    }
103
104    static T getValue(const cv::Mat& src, float y, float x, int c, int border_type, cv::Scalar borderVal = cv::Scalar())
105    {
106        const float xmin = ceilf(x - 2.0f);
107        const float xmax = floorf(x + 2.0f);
108
109        const float ymin = ceilf(y - 2.0f);
110        const float ymax = floorf(y + 2.0f);
111
112        float sum  = 0.0f;
113        float wsum = 0.0f;
114
115        for (float cy = ymin; cy <= ymax; cy += 1.0f)
116        {
117            for (float cx = xmin; cx <= xmax; cx += 1.0f)
118            {
119                const float w = bicubicCoeff(x - cx) * bicubicCoeff(y - cy);
120                sum += w * readVal<T>(src, (int) floorf(cy), (int) floorf(cx), c, border_type, borderVal);
121                wsum += w;
122            }
123        }
124
125        float res = (!wsum)? 0 : sum / wsum;
126
127        return cv::saturate_cast<T>(res);
128    }
129};
130
131#endif // __OPENCV_TEST_INTERPOLATION_HPP__
132