#include <opencv2/opencv.hpp>
#include <iostream>
using namespace std;
using namespace cv;
void ChangeImgBG();
Mat HandleImgData(Mat &img);
/*
图片背景替换
知识点：分水岭分割、高斯模糊
处理步骤：数据组装-KMeans分割-背景消除-生成遮罩-模糊-输出
*/
void ChangeImgBG()
{
char* win1 = "window1";
char* win2 = "window2";
char* win3 = "window3";
char* win4 = "window4";
char* win5 = "window5";
char* win6 = "window6";
namedWindow(win1,CV_WINDOW_AUTOSIZE);//创建窗口 win1
namedWindow(win2,CV_WINDOW_AUTOSIZE);//创建窗口 win2
namedWindow(win3,CV_WINDOW_AUTOSIZE);//创建窗口 win3
namedWindow(win4, CV_WINDOW_AUTOSIZE);//创建窗口 win4
namedWindow(win5, CV_WINDOW_AUTOSIZE);//创建窗口 win5
namedWindow(win6, CV_WINDOW_AUTOSIZE);//创建窗口 win6
Mat img1, img2;
//加载图片
img1 = imread("D:\\参考手册\\opencv素材\\xl.jpg");
if (img1.empty())
{
cout << "image not found..." << endl;
exit(0);//如果图片不存在，退出程序
}
img2 = img1.clone();
//显示原始图片
imshow(win1,img1);
//组装数据
Mat points = HandleImgData(img1);
//Kmeans处理
int numCluster = 4;
Mat labels;
Mat centers;
TermCriteria termCriteria = TermCriteria(TermCriteria::EPS + TermCriteria::COUNT,10,0.1);
kmeans(points, numCluster,labels, termCriteria,3,KMEANS_PP_CENTERS,centers);
//遮罩
Mat mask = Mat::zeros(img1.size(),CV_8UC1);
int index = img1.rows*2 + 2;
int cindex = labels.at<int>(index,0);//背景设置为0
int height = img1.rows;
int width = img1.cols;
for (int row = 0;row<height;row++)
{
for (int col =0;col<width;col++)
{
index = row*width + col;
int label = labels.at<int>(index,0);
if (label ==cindex)
{
img2.at<Vec3b>(row, col)[0] = 0;
img2.at<Vec3b>(row, col)[1] = 0;
img2.at<Vec3b>(row, col)[2] = 0;
mask.at<uchar>(row, col) = 0;
}
else
{
mask.at<uchar>(row, col) = 255;
}
}
}
//腐蚀
Mat k = getStructuringElement(MORPH_RECT,Size(3,3),Point(-1,-1));
erode(mask,mask,k);
imshow(win4,mask);
//高斯模糊
GaussianBlur(mask,mask,Size(3,3),0,0);
imshow(win5,mask);
//通道混合
RNG rng(12345);
Vec3b color;
color[0] = rng.uniform(0,255);
color[1] = rng.uniform(0, 255);
color[2] = rng.uniform(0, 255);
Mat result(img1.size(),img1.type());
double d1 = 0.0;
int r = 0, g = 0, b = 0;
int r1 = 0, g1 = 0, b1 = 0;
int r2 = 0, g2 = 0, b2 = 0;
for (int row = 0; row < height;row++)
{
for (int col=0;col<width;col++)
{
int m = mask.at<uchar>(row,col);
if (m==255)
{
result.at<Vec3b>(row, col) = img1.at<Vec3b>(row,col);//前景
}
else if (m == 0)
{
result.at<Vec3b>(row, col) = color;//背景
}
else
{
d1 = m / 255.0;
b1 = img1.at<Vec3b>(row, col)[0];
g1 = img1.at<Vec3b>(row, col)[1];
r1 = img1.at<Vec3b>(row, col)[2];
b2 = color[0];
g2 = color[1];
r2 = color[2];
b = b1*d1 + b2*(1.0-d1);
g = g1*d1 + g2*(1.0-d1);
r = r1*d1 + r2*(1.0-d1);
result.at<Vec3b>(row,col)[0] = b;
result.at<Vec3b>(row, col)[1] = g;
result.at<Vec3b>(row, col)[2] = r;
}
}
}
//输出
imshow(win2,mask);
imshow(win3,img2);
imshow(win6,result);
//保存处理后的图片
imwrite("result-2.jpg",result);
}
//组装样本数据
Mat HandleImgData(Mat &img)
{
int width = img.cols;
int height = img.rows;
int count1 = width*height;
int channels1 = img.channels();
Mat points(count1, channels1,CV_32F,Scalar(10));
int index = 0;
for (int row = 0; row < height;row++)
{
for (int col = 0; col < width;col++)
{
index = row*width + col;
Vec3b bgr = img.at<Vec3b>(row,col);
points.at<float>(index, 0) = static_cast<int>(bgr[0]);
points.at<float>(index, 1) = static_cast<int>(bgr[1]);
points.at<float>(index, 2) = static_cast<int>(bgr[2]);
}
}
return points;
}
int main()
{
ChangeImgBG();
waitKey(0);
return 0;
}
运行效果：
