Opencv 基于肤色的手势分割

首先通过摄像头采集图像，用Otsu方法进行二值化处理，然后找出最大两个连通区域，此处默认有手和脸，最后通过指尖检测算法，将脸部排除。
#include "cxcore.h"
#include "math.h"
#include <cmath>
#include <vector>
#include <stdio.h>
#include <string.h>
#include <sstream>
#include <time.h>
#include <iostream>
#include <cstring>
#include <cv.h>
#include <highgui.h>
#include <assert.h>

using namespace std;
using namespace cv;

void cvThresholdOtsu(IplImage* src,IplImage* dst)//otsu 最大类间差分法，一种自适应阈值确定方法
{
    int height = src->height;
    int width = src->width;

    float histogram[256] = {0};
    for (int i = 0; i < height; i++)
    {
        unsigned char* p = (unsigned char*)src->imageData + src->widthStep*i;
        for (int j = 0; j < width; j++)
        {
             histogram[*p++]++;
        }
    }
    int size = height * width;
    for (int i = 0; i < 256; i++)
    {
        histogram[i] = histogram[i] / size;
    }
    float avgValue = 0;
    for (int i = 0; i < 256; i++)
    {
        avgValue += i*histogram[i];
    }

    int threshold;
    float maxVariance = 0;
    float w = 0, u = 0;
    for (int i = 0; i < 256; i++)
    {
        w += histogram[i];
        u += i*histogram[i];
        float t = avgValue*w - u;
        float variance = t*t / (w*(1-w));
        if (variance > maxVariance)
        {
            maxVariance = variance;
               threshold = i;
        }
    }
    cvThreshold(src,dst,threshold,255,CV_THRESH_BINARY);
}

void cvSkinOtsu(IplImage* src,IplImage* dst)
{    
    assert(dst->nChannels == 1 && src->nChannels == 3);

       IplImage* ycrcb = cvCreateImage(cvGetSize(src),8,3);
       IplImage* cr = cvCreateImage(cvGetSize(src),8,1);
       cvCvtColor(src,ycrcb,CV_BGR2YCrCb);
       cvSplit(ycrcb,0,cr,0,0);
       cvThresholdOtsu(cr,cr);
       cvCopyImage(cr,dst);
       cvReleaseImage(&cr);
       cvReleaseImage(&ycrcb);
}

// 计算两点(p1,p2) 和 (p3,p4) 之间的距离 
double distance(double p1,double p2,double p3,double p4)
{
    double a = (p1 - p3)*(p1 - p3) + (p2 - p4)*(p2 - p4);
    double b = sqrt(a);
    return b;
}

//主函数
int main()
{        
    
    CvCapture* capture = cvCaptureFromCAM(0);//从对摄像头的初始化捕获
    if(!cvQueryFrame(capture))  cout<<"Video capture failed, please check the camera."<<endl;
    else cout<<"Video camera capture status: OK"<<endl;
     CvSize sz = cvGetSize(cvQueryFrame( capture));//得到摄像头图像大小

     IplImage* src = cvCreateImage( sz, 8, 3 );//3通道，每个通道8位
    IplImage* dst_crotsu = cvCreateImage(sz, 8, 1);
    IplImage* dst_MaxSecond = cvCreateImage(sz, 8, 1);
    IplImage* dst_hand = cvCreateImage(sz, 8, 3);
      CvMemStorage* storage = cvCreateMemStorage(0);//分配大小为0的内存空间
    CvMemStorage* storageHand = cvCreateMemStorage(0);
    CvMemStorage* dftStorage = cvCreateMemStorage(0);
    CvMemStorage* minStorage = cvCreateMemStorage(0);

    CvSeq* contour = 0;//用于选取最大两区域
    CvSeq* sq = 0;//用于选取手

      cvNamedWindow("source", CV_WINDOW_AUTOSIZE);//创建用于显示的窗口
    cvNamedWindow("cvSkinOtsu", CV_WINDOW_AUTOSIZE);
    cvNamedWindow("cvHandFace", CV_WINDOW_AUTOSIZE);
    cvNamedWindow("Hand", CV_WINDOW_AUTOSIZE);
    cvNamedWindow("bg", CV_WINDOW_AUTOSIZE);

    // 以下两行是为了计算图形的重心做准备 
    CvMoments moments;
     CvMat* region;
    //定义一些点和具体的参数 
    CvPoint pt1,pt2,ptmax;
    double m00 = 0,m10,m01,p1x,p1y,p2x,p2y,max,sum,average;
    int n = 0,Nc;

//    src = cvQueryFrame(capture);
//    cvShowImage("source", src);
//    cvSaveImage("test.img", src);
//    cout<<"hejhd"<<endl;    
     while(1)
    {
          IplImage* bg = cvCreateImage( sz, 8, 3);//
          cvRectangle( bg, cvPoint(0,0), cvPoint(bg->width,bg->height), CV_RGB( 255, 255, 255), -1, 8, 0 );//画矩形，参数：Image，两个顶点坐标，线的颜色，线的厚度(CV_FILLED时绘制填充了色彩的矩形)，线条类型，坐标点的小数点位数
          bg->origin = 0;//表示坐标系统的原点，0表示左上，1表示左下
          for(int b = 0; b< int(bg->width/10); b++)//画网格
          {
               cvLine( bg, cvPoint(b*20, 0), cvPoint(b*20, bg->height), CV_RGB( 200, 200, 200), 1, 8, 0 );//画竖线
            //cvLine（图像，线段的第一个端点，第二个端点，颜色，粗细，类型，坐标点的小数点位数）
               cvLine( bg, cvPoint(0, b*20), cvPoint(bg->width, b*20), CV_RGB( 200, 200, 200), 1, 8, 0 );//画横线
          }
        cvShowImage("bg", bg);
          src = cvQueryFrame(capture);//得到一帧图像
         cvSaveImage("src.jpg", src);
        cvShowImage("source", src);
    //    cvWaitKey(100);
        cvZero(dst_crotsu);
        cvSkinOtsu(src, dst_crotsu);//得到二值化图像

    //    cvShowImage("cvSkinOtsu", dst_crotsu);
        cvSaveImage("skinOtsu.jpg", dst_crotsu);
    
        cvThreshold(dst_crotsu, dst_crotsu, 127, 255, CV_THRESH_BINARY);

        int contour_num = cvFindContours(dst_crotsu, storage, &contour, sizeof(CvContour), CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE);//得到最大两轮廓
        double maxarea = 0;//
        double secondarea = 0;
        double minarea = 100;
        cvZero(dst_MaxSecond);
        CvSeq* _contour = contour;
        int m = 0;
        for(;contour != 0; contour = contour->h_next)
        {
            m++;
            double tmparea = fabs(cvContourArea(contour));
            if(tmparea < minarea) {cvSeqRemove(contour, 0); continue;}//删除噪声
            if(tmparea > maxarea) {secondarea = maxarea; maxarea = tmparea;}//得到最大面积
            else if(tmparea > secondarea) {secondarea = tmparea;}//得到第二大面积
        }

        contour = _contour;    
    
        for(; contour != 0; contour = contour->h_next)//画出最大两区域
        {
            double tmparea = fabs(cvContourArea(contour));
            if (tmparea == maxarea)
            {
                CvScalar color = CV_RGB(255, 255, 255);
                cvDrawContours(dst_MaxSecond, contour, color, color, 0, CV_FILLED);
            }
            else if (tmparea == secondarea)
            {
                CvScalar color = CV_RGB(255, 255, 255);
                cvDrawContours(dst_MaxSecond, contour, color, color, 0, CV_FILLED);
            }
        }

        cvShowImage("cvHandFace", dst_MaxSecond);
        cvSaveImage("handface.jpg", dst_MaxSecond);

    //    cvWaitKey(100);

        //选取手区域
        cvZero(dst_hand);
         cvThreshold(dst_MaxSecond, dst_MaxSecond,127,255,CV_THRESH_BINARY);
        Nc = cvFindContours(dst_MaxSecond, storageHand, &sq, sizeof(CvContour), CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE);
        for (; sq != NULL; sq = sq->h_next)
        {
            max = 0;
            sum = 0;
            average = 0;
            vector<CvPoint> pt_vec;
            vector<CvPoint>::iterator piter;
            n++;

            CvSeq* csq = cvApproxPoly(sq, sizeof(CvContour), storageHand, CV_POLY_APPROX_DP, 25, 0);// 相似多边形逼近该轮廓，以更好地求重心坐标 
            region = (CvMat*)csq;
            // 将保存多边形的矩阵region的重心计算出来并保存在moments中 
            cvMoments(region,&moments,0);
            m00 = moments.m00;  // 总重
            m10 = moments.m10;  // x轴重
            m01 = moments.m01; //  y轴重
            double inv_m00 = 1. / m00;  // 总重的倒数
            pt1.x = cvRound(m10 * inv_m00);  // 重心的横坐标
            p2x = pt1.x * 1.0;               // 用p2x表示重心的横坐标
            pt1.y = cvRound(m01 * inv_m00);  // 重心的纵坐标
            p2y = pt1.y * 1.0;     // 用p2y来表示重心的纵坐标，以方便计算距离   

            cout << "contour #" << n << ":" << endl;  // 打印当前的轮廓
            // 打印当前轮廓的重心 
            cout << "重心: " << "(" << p2x << "," << p2y << ")" << endl;
            // 打印当前轮廓包含像素点的总数 
            cout << "sq->total = " << sq->total << endl;
                                         
            //将当前轮廓中的每一个点保存在链表 pt_vec中 
            for (int i = 0; i < sq->total; ++i)
            {
                CvPoint* p = CV_GET_SEQ_ELEM(CvPoint,sq,i);
                pt_vec.push_back(*p);
            }
             // 将链表的迭代器指向链表中的第一个点上 
             piter = pt_vec.begin();
             //循环进行轮廓上每一个点的操作 
             for (; piter < pt_vec.end();++piter)
             {
                 pt2 = *piter;   // 将当前迭代器所指向的点保存在pt2中
                 p1x = pt2.x * 1.0; // 获取当前点的横坐标
                 p1y = pt2.y * 1.0; // 获取当前点的纵坐标
                 double d = distance(p1x,p1y,p2x,p2y); // 求当前点到重心的距离
                 sum += d;  // 每次将距离都加在sum，以便求总距离

                 //求最大距离所对应的点，把最大距离保存在max中，所对应的点 保存在 ptmax中 
                 if (d > max)
                 {
                     max = d;
                     ptmax = pt2;
                 }
              }

              //求轮廓所有的点到重心的平均距离 
              average = sum / (sq->total * 1.0);
              double ab = max / average;   // ab 就是那个倍数
              cout << "distanceMax = " << max << endl;  // 打印最大距离
              cout << "distanceAverage = " << average << endl; // 打印平均距离
              cout << "ab = " << ab << endl;  // 打印那个倍数
              if (ab < 1.5)     // 如果该倍数小于1.6,则舍弃该轮廓    改成1.5倍
              {
                  cout << "remove #" << n << endl;  // 打印删除的是哪个轮廓
                  cvSeqRemove(sq,0);  // 删除该轮廓
                  continue;
              }

              //将保留下的轮廓填充颜色显示 
              CvScalar color = CV_RGB(255,255,255);
              cvDrawContours(dst_hand,sq,color,color,-1,-1,8);

              //在bg图上确定手的区域
              CvRect rect = cvBoundingRect( sq, 0 );//返回一个2d矩形的点集合
                 cvRectangle( bg, cvPoint(rect.x, rect.y + rect.height), cvPoint(rect.x + rect.width, rect.y), CV_RGB(200, 0, 200), 1, 8, 0 );
                
              cvDrawContours(bg,sq,CV_RGB(127,0,0),CV_RGB(127,0,0),-1,-1,8);
              cvShowImage("bg",bg);
              
        }
    
    
        cvShowImage("Hand", dst_hand);
        cvSaveImage("hand.jpg", dst_hand);
    
        cvWaitKey(100);

    }
             
     cvReleaseCapture( &capture);
     cvDestroyAllWindows();
}