opencv绘制灰度直方图
2016-04-10 14:08 GarfieldEr007 阅读(1261) 评论(0) 编辑 收藏 举报代码之一:
#include <cv.h> #include <highgui.h> #pragma comment( lib, "cv.lib" ) #pragma comment( lib, "cxcore.lib" ) #pragma comment( lib, "highgui.lib" ) int main() { IplImage* src=cvLoadImage("lena.jpg",0); int width=src->width; int height=src->height; int step=src->widthStep; uchar* data=(uchar *)src->imageData; int hist[256]={0}; for(int i=0;i<height;i++) { for(int j=0;j<width;j++) { hist[data[i*step+j]]++; } } int max=0; for(i=0;i<256;i++) { if(hist[i]>max) { max=hist[i]; } } IplImage* dst=cvCreateImage(cvSize(400,300),8,3); cvSet(dst,cvScalarAll(255),0); double bin_width=(double)dst->width/256; double bin_unith=(double)dst->height/max; for(i=0;i<256;i++) { CvPoint p0=cvPoint(i*bin_width,dst->height); CvPoint p1=cvPoint((i+1)*bin_width,dst->height-hist[i]*bin_unith); cvRectangle(dst,p0,p1,cvScalar(0,255),-1,8,0); } cvNamedWindow("src",1); cvShowImage("src",src); cvNamedWindow("dst",1); cvShowImage("dst",dst); cvWaitKey(0); cvDestroyAllWindows(); cvReleaseImage(&src); cvReleaseImage(&dst); return 0; }
代码之二 :
#include <cv.h> #include <highgui.h> #pragma comment( lib, "cv.lib" ) #pragma comment( lib, "cxcore.lib" ) #pragma comment( lib, "highgui.lib" ) int main() { IplImage* src=cvLoadImage("lena.jpg",0); int size=256; float range[]={0,255}; float* ranges[]={range}; CvHistogram* hist=cvCreateHist(1,&size,CV_HIST_ARRAY,ranges,1); cvCalcHist(&src,hist,0,NULL); float max=0; cvGetMinMaxHistValue(hist,NULL,&max,NULL,NULL); IplImage* dst=cvCreateImage(cvSize(400,300),8,3); cvSet(dst,cvScalarAll(255),0); double bin_width=(double)dst->width/size; double bin_unith=(double)dst->height/max; for(int i=0;i<size;i++) { CvPoint p0=cvPoint(i*bin_width,dst->height); CvPoint p1=cvPoint((i+1)*bin_width,dst->height-cvGetReal1D(hist->bins,i)*bin_unith); cvRectangle(dst,p0,p1,cvScalar(0,255),-1,8,0); } cvNamedWindow("src",1); cvShowImage("src",src); cvNamedWindow("dst",1); cvShowImage("dst",dst); cvWaitKey(0); cvDestroyAllWindows(); cvReleaseImage(&src); cvReleaseImage(&dst); return 0; }
from: http://blog.csdn.net/abcjennifer/article/details/7315650