双线性插值与双三次插值算法代码 

  1 #include "opencv2/flann.hpp"
  2 #include "opencv2/opencv_modules.hpp"
  3 #include "opencv2/stitching/detail/matchers.hpp"
  4 #include "opencv2/imgcodecs/imgcodecs.hpp"
  5 #include "opencv2/highgui.hpp"
  6 #include <stdlib.h>
  7 #include <math.h>
  8 #include <vector>
  9 using namespace cv;
 10 
 11 
 12 
 13 #define INVALDE_DEM_VALUE  -9999999
 14 
 15 /**
 16     * @brief 双线性插值
 17     * 
 18     * @param x 插值点列坐标
 19     * @param y 插值点行坐标
 20     * @param pdfValue 影像数据
 21     * @param nWidth 影像数据宽度
 22     * @param nHeight 影像数据高度
 23     */
 24     double ResampleBilinear(double x, double y, double * pdfValue, int nWidth, int nHeight)
 25     {
 26         double dfBilinearValue;
 27         //双线性插值计算    
 28         int x_floor = x;
 29         int x_ceil = (x+1);
 30         int y_floor = y;
 31         int y_ceil = (y+1);
 32 
 33         /*we do not handle the border, attention*/
 34         if(x<0 || y<0 || (y+1) > (nHeight-1) || (x+1) > (nWidth-1) )
 35             return INVALDE_DEM_VALUE;
 36 
 37         double r1 = (x_ceil - x)*pdfValue[y_ceil*nWidth+x_floor]
 38         + (x- x_floor)*pdfValue[y_ceil*nWidth+x_ceil];
 39 
 40         double r2 = (x_ceil - x)*pdfValue[y_floor*nWidth+x_floor] 
 41         + (x- x_floor)*pdfValue[y_floor*nWidth+x_ceil];
 42 
 43         dfBilinearValue = (y-y_floor)*r1 + (y_ceil - y)*r2;
 44 
 45         return dfBilinearValue; // 所有波段都是无效值才返回false
 46     }
 47 
 48 
 49 double cubic_coeff(double x){
 50     x = (x>0)? x : -x;
 51     if (x<1){
 52         return 1-2*x*x+x*x*x;
 53     }else if(x<2){
 54         return 4-8*x+5*x*x-x*x*x;
 55     }
 56     return 0;
 57 }
 58 
 59 /**
 60 * @brief 三次卷积
 61 * 
 62 * @param x 插值点列坐标
 63 * @param y 插值点行坐标
 64 * @param pdfValue 影像数据
 65 * @param nWidth 影像数据宽度
 66 * @param nHeight 影像数据高度
 67 */
 68 double ResampleCubic(double x, double y, double * pdfValue, int nWidth, int nHeight)
 69 {
 70     double dfCubicValue;
 71     int i = x;
 72     int j = y;
 73 
 74     /*we do not handle the border, attention*/
 75     if((i-1)<0 || (j-1)<0 || (j+2) > (nHeight-1) || (i+2) > (nWidth-1) )
 76         return INVALDE_DEM_VALUE;
 77 
 78     /*get adjacent 16 values*/
 79     double values[4][4];
 80     for (int r = j-1,s=0; r <= j+2; r++,s++){
 81         for (int c = i-1,t=0; c <= i+2; c++,t++){
 82             values[s][t] = pdfValue[r*nWidth+c];
 83         }
 84     }
 85 
 86     /*calc the coeff*/
 87     double u = x - i;
 88     double v = y - j;
 89     double A[4],C[4];
 90     for (int distance =1,s=0;distance >=-2; distance --,s++){
 91         A[s] = cubic_coeff(u+distance);
 92         C[s] = cubic_coeff(v+distance);
 93     }
 94 
 95     dfCubicValue = 0;
 96     for (int s = 0; s < 4; s++)    {
 97         for (int t = 0; t < 4; t++){
 98             dfCubicValue += values[s][t]*A[t]*C[s];
 99         }
100     }
101     return dfCubicValue; 
102 }
103 
104 void main(){
105     Mat pano = cv::imread("D:/warehouse/data/test.jpg");
106     Mat gray;
107     cvtColor(pano, gray,CV_BGR2GRAY);
108     Mat gray32;
109     gray.convertTo(gray32,CV_64FC1);
110 
111 
112     Mat bil(gray32.rows*2, gray32.cols*2, CV_64FC1);
113     Mat cub(gray32.rows*2, gray32.cols*2, CV_64FC1);
114 
115     /*copy MAT  data to a buffer*/
116     int stride = gray32.step.p[0];
117     double *data = new double[gray32.cols* gray32.rows];
118     for (int i = 0; i < gray32.rows; i++){
119         char* p = ((char*)data)+i* gray32.cols*sizeof(double);
120         memcpy(p, gray32.data+stride*i, gray32.cols*sizeof(double));
121     }
122 
123     /*interpolate, Bilinear*/
124     for (int r = 0; r < bil.rows; r++){
125         for (int c = 0; c < bil.cols; c++){
126             double k = r/2.0;
127             double j = c/2.0;
128             bil.at<double>(r,c) = ResampleBilinear(j, k, data, gray32.cols, gray32.rows);
129         }
130     }
131     
132 
133     /*interpolate, Cubic3*/
134     for (int r = 0; r < bil.rows; r++){
135         for (int c = 0; c < bil.cols; c++){
136             double k = r/2.0;
137             double j = c/2.0;
138             cub.at<double>(r,c) = ResampleCubic(j, k, data, gray32.cols, gray32.rows);
139         }
140     }
141 
142     Mat bilShow;
143     bil.convertTo(bilShow,CV_8UC1);
144     namedWindow("bil",1);
145     imshow("bil",bilShow);
146     imwrite("d:/bil.jpg", bilShow);
147 
148     namedWindow("pano",1);
149     imshow("pano",pano);
150     Mat cubShow;
151     cub.convertTo(cubShow,CV_8UC1);
152     namedWindow("cub",1);
153     imshow("cub",cubShow);
154     imwrite("d:/cub.jpg", cubShow);
155 
156     waitKey();
157     return;
158 }

参考：http://baike.baidu.com/link?url=femZWLyq-bZ3tX887kzps3vfKspkdugWNs4k9MV4Cq7RiXtGz8gvao3Ac2Or0DE3Mf8ooIG0ZaqdgzobnL6me_

posted @ 2016-09-01 09:37  小阳明  阅读(8302)  评论(0)  编辑  收藏  举报