OpenCV--调整图像亮度和对比度

//调整图像亮度和对比度
void Demo(){
Mat src,dest;
src = imread("sanli.jpg");
if(!src.data){
cout << "图片打开失败！" << endl;
return;
}
namedWindow("原图像",CV_WINDOW_AUTOSIZE);
imshow("原图像",src);
dest = Mat::zeros(src.size(),src.type());
int rows = src.rows;
int cols = src.cols;
int n = src.channels();//通道数

float alpha = 1.5;
float beta = 30;
for(int row = 0;row<rows;row++){
for(int col = 0;col<cols;col++){
if(n==3){
int b = src.at<Vec3b>(row,col)[0];
int g = src.at<Vec3b>(row,col)[1];
int r = src.at<Vec3b>(row,col)[2];

dest.at<Vec3b>(row,col)[0] = saturate_cast<uchar>(alpha*b+beta);
dest.at<Vec3b>(row,col)[1] = saturate_cast<uchar>(alpha*g+beta);
dest.at<Vec3b>(row,col)[2] = saturate_cast<uchar>(alpha*r+beta);

}else{
if(n==1){
dest.at<uchar>(row,col) = saturate_cast<uchar>(alpha*src.at<uchar>(row,col)+beta);
}
}
}
}

namedWindow("增强后",CV_WINDOW_AUTOSIZE);
imshow("增强后",dest);
cvWaitKey();
}

float b = src.at<Vec3f>(row,col)[0];
float g = src.at<Vec3f>(row,col)[1];
float r = src.at<Vec3f>(row,col)[2];

一旦我们运行就会产生错误：



解决方法：

在for循环之前添加代码：

src.convertTo(src,CV_32F);