图片对比度增强

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv/cv.h>  using namespace cv;IplImage *DrawHistogram(CvHistogram *hist,float scaleX = 1,float scaleY = 1){float histMax = 0;cvGetMinMaxHistValue(hist,0,&histMax,0,0);IplImage *imgHist = cvCreateImage(cvSize(256*scaleX,64*scaleY),8,1);cvZero(imgHist);for(int i=0;i<255;i++){float histValue = cvQueryHistValue_1D(hist,i);float nextValue = cvQueryHistValue_1D(hist,i+1);CvPoint pt1 = cvPoint(i*scaleX,64*scaleY);CvPoint pt2 = cvPoint((i+1)*scaleX,64*scaleY);CvPoint pt3 = cvPoint((i+1)*scaleX,64*scaleY - (nextValue/histMax) * 64*scaleY);CvPoint pt4 = cvPoint(i*scaleX,64*scaleY - (histValue/histMax) * 64*scaleY);int numPts = 5;CvPoint pts[5];pts[0] = pt1;pts[1] = pt2;pts[2] = pt3;pts[3] = pt4;pts[4] = pt1;cvFillConvexPoly(imgHist,pts,numPts,cvScalar(255));}return imgHist;
}int main(int argc , char** argv){cv::Mat image;int dims = 1;int size = 256;float range[] = {0,255};float* ranges[] = {range};Mat mat;IplImage src;if(argc < 2){printf("Please input picture!\n");return -1;}mat = imread(argv[1], 0);src = mat;cvShowImage("src", &src);CvHistogram *hist = cvCreateHist(dims,&size,CV_HIST_ARRAY,ranges,1);cvClearHist(hist);IplImage *imgGray = cvCreateImage(cvGetSize(&src),8,1);cvSplit(&src,imgGray, NULL, NULL, NULL);cvCalcHist(&imgGray, hist, 0, 0);IplImage *histGray = DrawHistogram(hist);cvClearHist(hist);cvShowImage("Gray",histGray);cv::waitKey(0);return 0;
}

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv/cv.h>  using namespace cv;int main(int argc , char** argv){cv::Mat image;int size = 256;Mat mat;IplImage src;int i, j, width, height;int c[size];double p[size];CvScalar s1;double max, min;if(argc < 2){printf("Please input picture!\n");return -1;}mat = imread(argv[1], 0);src = mat;imshow("src", mat);width = mat.rows;height = mat.cols;uchar* ptr = mat.ptr(0);for(i=0; i<size; i++){p[i] = 0;c[i] = 0;   }max=min=ptr[0];for(i=0; i<width; i++){for(j=0;j<height; j++){int k;s1 = cvGet2D(&src, i, j);k = (int)s1.val[0];c[k]++;if(max<s1.val[0]){max=s1.val[0];}else if(min>s1.val[0]){min=s1.val[0];}}}printf("min:%lf, max:%lf\n", min, max);for(i=0;i<size;i++){if(i > 0){p[i] += p[i - 1];}p[i] += ((double)c[i])/((double)(width*height));printf("p[%d]:%lf, c[%d]:%d\n", i, p[i], i, c[i]);}for(i=0; i<width; i++){for(j=0; j<height; j++){s1 = cvGet2D(&src, i, j);s1.val[0] = p[(int)s1.val[0]] * (max-min) + min;cvSet2D(&src, i, j, s1);}}imshow("dst", mat);imwrite("dst1.png", mat);cv::waitKey(0);return 0;
}

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv/cv.h>  using namespace cv;#define throDark 30
#define throMid 100
#define throBright 170double getUdark(double num){double tmpUdark;if(num <= throDark){tmpUdark = 1;   }else if((num > throDark) && (num <= throMid)){tmpUdark  = ((double)(throMid - num)) / ((double)(throMid - throDark));}else{tmpUdark = 0;   }return tmpUdark;
}double getUmid(double num){double tmpUmid;if((num > throDark) && (num < throMid)){tmpUmid  = (num - throDark) / (throMid - throDark);}else if((num >= throMid) && (num < throBright)){tmpUmid  = (throBright - num) / (throBright - throMid);}else{tmpUmid = 0;    }return tmpUmid;
}double getUbright(double num){double tmpUbright;if(num <= throMid){tmpUbright = 0; }else if((num > throMid) && (num <= throBright)){tmpUbright  = (num - throMid) / (throBright - throMid);}else{tmpUbright = 1;}return tmpUbright;
}int main(int argc , char** argv){cv::Mat image;Mat mat;IplImage src;int i, j, width, height;CvScalar s1;int Uall;double tmp, Udark, Umid, Ubright;if(argc < 2){printf("Please input picture!\n");return -1;}mat = imread(argv[1], 0);src = mat;imshow("src", mat);width = mat.rows;height = mat.cols;uchar* ptr = mat.ptr(0);for(i=0; i<width; i++){for(j=0;j<height; j++){s1 = cvGet2D(&src, i, j);Udark   = getUdark(s1.val[0]);Umid    = getUmid(s1.val[0]);Ubright = getUbright(s1.val[0]);s1.val[0] = (0 * Udark + 127 * Umid + 255 * Ubright) / (Udark + Umid + Ubright);
//          printf("Udark:%lf, Umid:%lf, Ubright:%lf, s1.val[0]%lf\n", Udark, Umid, Ubright, s1.val[0]);cvSet2D(&src, i, j, s1);}}imshow("dst", mat);imwrite("dst2.png", mat);cv::waitKey(0);return 0;
}