图像检索：二维直方图+EMD距离

#include<iostream>
#include<fstream>
#include<map>
#include<string>
using namespace std;

#include<opencv2\core\core.hpp>
#include<opencv2\highgui\highgui.hpp>
#include<opencv2\imgproc\imgproc.hpp>
using namespace cv;

Mat signature(const Mat & src);
int main(int argc,char* argv[])
{
//定义文件流，只能读取
ifstream inPutFile(argv[1],ios::in);
if(! inPutFile)
{
cerr <<"File Open Erro !"<<endl;
return -1;
}

//读取文件流中的每一行，并赋值给fileName,形成查询数据库
string fileName;
Mat image,imageSignature,sourceSignature;
vector<Mat> signatures;

map<int,string> index;//图像的索引
index.clear();
int number = 0;
signatures.clear();
while(getline(inPutFile,fileName))
{
index.insert(pair<int,string>(number,fileName));
number++;
image = imread(fileName,1);
imageSignature =  signature(image);
signatures.push_back(imageSignature);
}

//待搜索的图像
number = 0;
Mat imageSource = imread(argv[2],1);
sourceSignature = signature(imageSource);
vector<Mat>::iterator iter;
map<float,int> distance;
for(iter = signatures.begin();iter != signatures.end();iter ++)
{
distance.insert(pair<float,int>(EMD(sourceSignature,*iter,CV_DIST_L2,number),number));
number ++;
}
//显示距离最小的前五名的检索图像
number = 0;
map<float,int>::iterator mapiter;
for(mapiter = distance.begin();mapiter != distance.end() && number <1;mapiter++,number++)
{
string simage = index.find((*mapiter).second)->second;
image = imread(simage,1);
namedWindow(simage,1);
imshow(simage,image);
}
waitKey(0);
return 0;
}

Mat signature(const Mat & src)
{
Mat hsv,hist,normalHist,histCol;
//颜色空间转换
cvtColor(src,hsv,CV_BGR2HSV);
//二维直方图
int hbins = 30;
int sbins  = 16;
int histSize[] = {hbins,sbins};
float hranges[] = {0.0,180.0};
float sranges[] = {0.0,256.0};
const float* ranges[] = {hranges,sranges};

int channels[] ={0,1};
calcHist(&hsv,1,channels,Mat(),hist,2,histSize,ranges,true,false);
//把直方图特征按一列来存储
int rows = hbins*sbins;
histCol = hist.reshape(1,rows);
//把直方图归一化
normalize(histCol,normalHist,1000,0,CV_L1,CV_32F);

Mat signature(hbins*sbins,3,CV_32FC1);
normalHist.copyTo(signature.col(0));

//我们把bin的索引放在signature的第二列和第三列
for(int h =0 ;h<hbins;h++)
{
Mat roi(signature,Rect(1,h*sbins,2,sbins));
for(int s= 0;s<sbins;s++)
{
roi.at<float>(s,0) = float(h);
roi.at<float>(s,1) =float(s);
}
}
return signature;
}