【Opencv】大律法求阈值+分割图像计算像素比

#include "opencv2/highgui/highgui.hpp"  
#include "opencv2/imgproc/imgproc.hpp"  
#include "opencv2/core/core.hpp"
#include <opencv\ml.h>
#include <iostream>
#include <vector>
#include <math.h>
#include <string.h>
using namespace std;
using namespace cv;;

//大津法求阈值
int otsu1(Mat frame)
{
//frame灰度级
int width=frame.rows;
int	height=frame.cols;
int pixelCount[256]={0};
float pixelPro[256]={0};
int i, j, pixelSum = width * height, threshold = 0;
uchar* data = frame.data;
float w0, w1, u0tmp, u1tmp, u0, u1, deltaTmp, deltaMax = 0;
//统计每个灰度级中像素的个数
for(i = 0; i < height; i++)
{
for(j = 0;j < width;j++)
{
pixelCount[(int)data[i * width + j]]++;
}
}
//计算每个灰度级的像素数目占整幅图像的比例
for(i = 0; i < 256; i++)
{
pixelPro[i] = (float)pixelCount[i] / pixelSum;
}
//遍历灰度级[0,255],寻找合适的threshold
for(i = 0; i < 256; i++)
{
w0 = w1 = u0tmp = u1tmp = u0 = u1 = deltaTmp = 0;
for(j = 0; j < 256; j++)
{
if(j <= i)   //背景部分
{
w0 += pixelPro[j];
u0tmp += j * pixelPro[j];
}
else   //前景部分
{
w1 += pixelPro[j];
u1tmp += j * pixelPro[j];
}
}
u0 = u0tmp / w0;
u1 = u1tmp / w1;
deltaTmp = (float)(w0 *w1* pow((u0 - u1), 2)) ;
if(deltaTmp > deltaMax)
{
deltaMax = deltaTmp;
threshold = i;
}
}
return threshold;
}
//计算每个小块所占比例，存入向量
float Bili1(Mat src)
{

float BL,counter = 0;
int Sqaure = src.cols * src.rows;

Mat_<uchar>::iterator it = src.begin<uchar>();
Mat_<uchar>::iterator itend = src.end<uchar>();
for (; it!=itend; ++it)
{
if((*it)>0) counter+=1;
}
BL = counter/Sqaure;
return BL;
}
vector<float> Devide441(Mat img)
{
//归一化，灰度化，二值化
resize(img,img,Size(16,32));
cvtColor(img,img,COLOR_BGR2GRAY);
int th = otsu1(img);
cv::threshold(img,img,th,255,THRESH_BINARY);

//切割为4*4
int a = img.cols/4;
int b = img.rows/4;
vector<float> reback;
for(int i = 0; i<4 ;++i)
{
for(int j = 0; j<4 ;++j)
{
Rect roi_rect = Rect(Point(j*a,i*b),Size(a,b));
Mat roi = img(roi_rect);
float BL = Bili1(roi);

reback.push_back(BL);
}
}
return reback;

}

int main()
{
Mat img1 = imread("train/7.bmp",1);
imshow("img1",img1);
vector<float> a = Devide441(img1);

Mat A = Mat(a);
cout<<A<<endl;

Mat img2 = imread("LP8.jpg",1);
imshow("img2",img2);
vector<float> b = Devide441(img2);
Mat B = Mat(b);
cout<<B<<endl;

waitKey();
return 0;

}