用鼠标框选图片感兴趣区域并提取灰度直方图

                                           Jun.L

                   http://blog.csdn.net/jingjun1822

    最近看了很多提取边缘局部特征的文章，包括Hog，Snake等等，会在这段时间内分享我的阅读心得。CV刚刚接触不久，基础薄弱，见识短浅。简直是要理论没理论，要代码没代码。不过既然在做了就不能急躁，应该静下心来，扎扎实实地走好每一步。因为是初学者，理论分析不到位或者代码有误的地方，前辈们看到了还望不吝赐教，在此先谢过了。

    为了做一些局部特征的分析，我把以前所编的用鼠标提取图片感兴趣区域并提取灰度直方图的opencv程序拿了出来，打算把它改造成提取一些局部特征的工具。程序运行环境opencv2.4.3+VS2010。参考资料OpenCV2 Computer Vision Application Programmming Cookbook是一本学习opencv2.0系列的C++接口的好书。

下载链接：http://download.csdn.net/detail/a973206267/6996239

main.cpp    

//Use mouse to get gray histogram form RIO//Author:Jun.L//Data:2013-12-10//Homepage://Email:[e-mail]//references:OpenCV2 Computer Vision Application Programmming Cookbook#include "stdafx.h"#include <cv.h>#include <cxcore.h>#include <highgui.h>#include "Ms_program.h"#include <iostream>using namespace std;using namespace cv;CvRect ROI_rect; IplImage* workImg=NULL;IplImage* Imgshow=NULL;bool check_line_state=false;void on_mouse4(int event, int x,int y,int flags, void* param);int _tmain(int argc, _TCHAR* argv[]){workImg=cvLoadImage("E:\\dataset\\input\\pics\\head977.jpg",-1);if(!workImg){    cout<<"Open File Error!"<<endl;return -1;}Imgshow=cvCreateImage(cvSize(workImg->width,workImg->height),workImg->depth,workImg->nChannels);  cvCopy(workImg,Imgshow);cvNamedWindow("image",1); cvShowImage( "image",workImg); cvSetMouseCallback("image",on_mouse4);//cv::Mat Matinput(MP1.Imginput,false);cvWaitKey(0); cvReleaseImage(&Imgshow);cvReleaseImage(&workImg);}void on_mouse4(int event, int x,int y,int flags, void* param){int thickness=2;CvPoint p1,p2;if(event==CV_EVENT_LBUTTONDOWN){    //left button of mouse is down    ROI_rect.x=x;ROI_rect.y=y;check_line_state=true;}else if(check_line_state&&event==CV_EVENT_MOUSEMOVE){    Imgshow = cvCreateImage(cvGetSize(workImg), IPL_DEPTH_8U, 3);//use Imgshow to show that we draw a green rect in it  Imgshow  = cvCloneImage(workImg);p1=cvPoint(ROI_rect.x,ROI_rect.y);p2=cvPoint(x,y);cvRectangle(Imgshow,p1,p2,CV_RGB(0,255,150),thickness,CV_AA,0);cvShowImage("image",Imgshow); cvReleaseImage(& Imgshow); }else if(check_line_state&&event==CV_EVENT_LBUTTONUP){   //left button of mouse is upROI_rect.width = abs(x - ROI_rect.x); ROI_rect.height = abs(y - ROI_rect.y);cvSetImageROI(workImg, ROI_rect); IplImage* RoiImg;IplImage* Imggray;Imggray = cvCreateImage(cvSize(ROI_rect.width,ROI_rect.height),8,1);RoiImg = cvCreateImage(cvSize(ROI_rect.width,ROI_rect.height),8,3);cvCopy(workImg,RoiImg);cvResetImageROI(workImg);cvNamedWindow("ROI",1);cvShowImage("ROI",RoiImg);/***********************draw the gray histogram*************************/cvCvtColor(RoiImg,Imggray,CV_RGB2GRAY); Mos_pro MP1;cvNamedWindow("histogram",1);    cv::imshow("histogram",MP1.getHistogramImage(Imggray));cv::MatND histo=MP1.getHistogram(Imggray);for(int i=0;i<256;i++)cout<<"value"<<i<<"="<<histo.at<float>(i)<<endl;cvReleaseImage(&RoiImg);cvReleaseImage(&Imggray);    check_line_state=false;cvWaitKey(20);}  }

Ms_program.h    

#if !defined MS_PROGRAM#define MS_PROGRAM#include "stdafx.h"#define  WINSIZE 3#include <cv.h>#include <cxcore.h>#include <highgui.h>#include <math.h>#include <iostream>using namespace std;using namespace cv;class Mos_pro{public:Mos_pro();cv::MatND getHistogram(const cv::Mat &image){    cv::MatND hist;// Compute histogramcv::calcHist(&image, 1,// histogram of 1 image onlychannels,// the channel usedcv::Mat(),// no mask is usedhist,// the resulting histogram1,// it is a 1D histogramhistSize,// number of binsranges// pixel value range);return hist;}cv::Mat getHistogramImage(const cv::Mat &image){// Compute histogram firstcv::MatND hist= getHistogram(image);// Get min and max bin valuesdouble maxVal=0;double minVal=0;cv::minMaxLoc(hist, &minVal, &maxVal, 0, 0);// Image on which to display histogramcv::Mat histImg(histSize[0], histSize[0], CV_8U,cv::Scalar(255));// set highest point at 90% of nbinsint hpt = static_cast<int>(0.9*histSize[0]);// Draw vertical line for each bin for( int h = 0; h < histSize[0]; h++ ) {float binVal = hist.at<float>(h);int intensity = static_cast<int>(binVal*hpt/maxVal);cv::line(histImg,cv::Point(h,histSize[0]),cv::Point(h,histSize[0]-intensity),cv::Scalar::all(0));}return histImg;}private:int histSize[1];float hranges[2];    const float* ranges[1];    int channels[1];};#endif

Ms_program.cpp

#include "stdafx.h"#include "Ms_program.h"#include <cv.h>#include <cxcore.h>#include <highgui.h>#include <math.h>#include <iostream>using namespace std;using namespace cv;Mos_pro::Mos_pro(){    // Prepare arguments for 1D histogramhistSize[0]= 256;hranges[0]= 0.0;hranges[1]= 255.0;ranges[0]= hranges; channels[0]= 0; // by default, we look at channel 0}