基于动态阈值的白平衡算法 照片校色

话不多说，原理见上一篇博客，结果耶很好，直接贴代码：

/*这个是基于动态阈值的自动白平衡算法做的照片颜色校正的程序*/
/*Automatic White Balance Method*/
/*输入包含照片名字的txt文本，输出加前缀的较色后的照片*/
/*时间:2015.8.24*/
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/face.hpp>
#include <opencv2/xphoto/white_balance.hpp>
#include <opencv2/xphoto.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <vector>
using namespace std;
using namespace cv;
double baidianave(Mat frame,int n)
{
int a[256];
for (int i=0;i<256;i++)
{
a[i]=0;
}
double sum=0;
double ave;
for (int i=0;i<n;i++)
{
int d=frame.at<double>(0,i);
a[d]++;
}
int n0=255;
for (int k=255;k>0;k--)
{
sum+=a[k];
if (sum>frame.rows*frame.cols/10)
{
break;
}
n0--;
}
sum=0;
for (int i=n0;i<256;i++)
{
sum+=a[i]*i;
}
ave=sum/(frame.rows*frame.cols/10);
return ave;
}
double baidianave(Mat frame)
{
int a[256];
//cvZero(a);
for (int i=0;i<256;i++)
{
a[i]=0;
}
double sum=0;
double ave;
for (int i=0;i<frame.rows;i++)
{
for (int j=0;j<frame.cols;j++)
{
int d=(int)frame.at<uchar>(i,j);
a[d]++;
}
}

int n0=255;
for (int k=255;k>0;k--)
{
sum+=a[k];
if (sum>frame.rows*frame.cols/10)
{
break;
}
n0--;
}
sum=0;
for (int i=n0;i<256;i++)
{
sum+=a[i]*i;
}
ave=sum/(frame.rows*frame.cols/10);
return ave;

}

int main(int argc, char* argv[])
{
if (2 != argc)
{
cout << "Please enter the image list!" <<endl;
return -1;
}
vector<string> file_names;
FILE *file_list = fopen(argv[1],"r");
char buf[255];
memset(&buf,0,sizeof(buf));

while(fgets(buf,255,file_list))
{
if(buf[strlen(buf)-1] == '\n')
buf[strlen(buf)-1] = '\0';
file_names.push_back(string(buf));

}

fclose(file_list);
int count = file_names.size();
for(int i=0; i<count; i++)
{
string img_nm = file_names[i];
string img_mask = "c2" + img_nm;
int pos = img_nm.rfind('.');
string img_fmt = img_nm.substr(pos+1);
if("jpg" != img_fmt)
{
cout << "Unknown format: " << img_fmt << endl;
continue;
}
Mat frame= imread(img_nm,1);
// cout<<frame.rows<<" "<<frame.cols<<endl;
// cvShowImage("处理前图像",frame);
int heightyiban=frame.rows;
int widthyiban=frame.cols;
double Mb,Db;//图像分成四部分，每部分Cb的均值和均方差
double Mr,Dr;//Cr的均值和均方差
Mat imageYCrCb = Mat::zeros(frame.size(), CV_8UC3);
Mat imageCb = Mat::zeros(frame.size(), CV_8UC1);
Mat imageCr = Mat::zeros(frame.size(), CV_8UC1);
Mat imageY = Mat::zeros(frame.size(), CV_8UC1);
cvtColor(frame,imageYCrCb,CV_BGR2YCrCb);

std::vector<cv::Mat>ybr(imageYCrCb.channels());
split(imageYCrCb,ybr);

Mat imageb=Mat::zeros(frame.size(), CV_8UC1);
Mat imagec=Mat::zeros(frame.size(), CV_8UC1);
ybr[1].copyTo(imageb);
ybr[2].copyTo(imagec);
Mat savg,sfangcha;//全局scalar 变量用来放平均值和方差
meanStdDev(ybr[2],savg,sfangcha);
Mb=savg.at<double>(0);
Db=sfangcha.at<double>(0);//求出第一部分cb的均值和均方差
meanStdDev(ybr[1],savg,sfangcha);
Mr=savg.at<double>(0);
// cout<<"Mr: "<<Mr[0]<<endl;
Dr=sfangcha.at<double>(0);;//求出第一部分cr的均值和均方差
// cout<<"Dr: "<<Dr[0]<<endl;
double b,c;
if (Mb<0)//计算mb+db*sign（mb）
{
b=Mb+Db*(-1);
}
else
b=Mb+Db;

if (Mr<0)//计算1.5*mr+dr*sign（mb）；
{
c=1.5*Mr+Dr*(-1);
}
else
c=1.5*Mr+Dr;
double Ymax=baidianave(ybr[0]);
//下面是对第一部分进行白点的选择
Mat Bbaidian=Mat::zeros(1,6000000,CV_64FC1);
Mat Gbaidian=Mat::zeros(1,6000000,CV_64FC1);
Mat Rbaidian=Mat::zeros(1,6000000,CV_64FC1);

//CvScalar s1;
int n1=0;
// cout<<"b[0]: "<<b[0]<<" c[0]: "<<c[0]<<endl;
for (int i=0;i<heightyiban;i++)
{
for (int j=0;j<widthyiban;j++)
{
if (((ybr[2].at<uchar>(i,j)-b)<(1.5*Db))&&((ybr[1].at<uchar>(i,j)-c)<(1.5*Dr)))
{

double d1=frame.at<Vec3b>(i,j)[0];
Bbaidian.at<double>(0,n1)=d1;

double d2=frame.at<Vec3b>(i,j)[1];
Gbaidian.at<double>(0,n1)=d2;

double d3=frame.at<Vec3b>(i,j)[2];
Rbaidian.at<double>(0,n1)=d3;
n1++;
}
}
}

double Bave1=baidianave(Bbaidian,n1);
double Gave1=baidianave(Gbaidian,n1);
double Rave1=baidianave(Rbaidian,n1);
// cout<<"Bave1: "<<Bave1<<" Gave1: "<<Gave1<<" Rave1: "<<Rave1<<" Ymax: "<<Ymax<<endl;
double Bgain1=Ymax/(Bave1);
double Ggain1=Ymax/(Gave1);
double Rgain1=Ymax/(Rave1);
// cout<<Bgain1<<" "<<Ggain1<<" "<<Rgain1<<endl;
for (int i=0;i<heightyiban;i++)
{
for (int j=0;j<widthyiban;j++)
{
int tb=Bgain1*frame.at<Vec3b>(i,j)[0];
int tg=Ggain1*frame.at<Vec3b>(i,j)[1];
int tr=Rgain1*frame.at<Vec3b>(i,j)[2];
if (tb>255)
{
tb=255;
}
if (tg>255)
{
tg=255;
}
if (tr>255)
{
tr=255;
}
frame.at<Vec3b>(i,j)[0]=tb;
frame.at<Vec3b>(i,j)[1]=tg;
frame.at<Vec3b>(i,j)[2]=tr;
}
}
imwrite(img_mask.c_str(),frame);
cout<<"Finish!"<<endl;
}

return 0;
}