Question

我想知道Mat图像中Vec3b像素中的值。我不是真正的OpenCV专家。我的Vec3b是，如果我打印Vec3b：

Vec3b centralIntensity;
cx=70; cy=700;
centralIntensity = (Vec3b)imgTemp->at<Vec3b>(cx, cy);
cout<<"I:["<<cx<<","<<cy<<"]="<<centralIntensity<<endl;

我明白了：

我：[70,700] = [150,162,160]

如果我打印单个值：

 cout<<"***Uchar:["<<cx<<","<<cy<<"]="<<int(centralIntensity[0])<<","<<int(centralIntensity[1])<<","<<int(centralIntensity[2])<<endl;

我明白了：

UCHAR：[70700] = 127,0,0

我注意到如果我更改坐标，最后一次打印始终是相同的。由于我必须比较不同通道上的强度像素，这样做的好方法是什么，并且知道BGR通道中的像素值？

*** EDIT1：这是我创建Mat图像的方式（我已经有了一个Mat imgIn作为输入），我以另一种方式显示Vec3b：

Mat *imgTemp;
uchar cblue, blue, cgreen;
imgTemp = new Mat(imgIn->size(), CV_8UC3);
imgIn->convertTo(*imgTemp, CV_8UC3);
Vec3b centralIntensity;
centralIntensity = (Vec3b)imgTemp->at<Vec3b>(cx, cy);
cout<<"I:["<<cx<<","<<cy<<"]="<<centralIntensity<<endl;
centralIntensity[0] = cblue;
centralIntensity[1] = cgreen;
centralIntensity[2] = cred;
cout<<"I:["<<cx<<","<<cy<<"]="<<centralIntensity<<endl;
cout<<"***Uchar:["<<cx<<","<<cy<<"]="<<int(centralIntensity[0])<<","<<int(centralIntensity[1])<<","<<int(centralIntensity[2])<<endl;
cout<<"***Uchar:["<<cx<<","<<cy<<"]="<<int(cblue)<<","<<int(cgreen)<<","<<int(cred)<<endl;

我明白了：

我：[70,700] = [150,162,160]

*** UCHAR：[70700] = 127,0,0

*** UCHAR：[70700] = 127,0,0

如果我更改坐标？

我：[300,400] = [109,123,105]

*** UCHAR：[300400] = 127,0,0

*** UCHAR：[300400] = 127,0,0

Answer 1

您正在使用未初始化的值centralIntensity，cblue，cred覆盖cgreen，其中包含随机值。

只需更正作业：

cblue = centralIntensity[0];
cgreen = centralIntensity[1];
cred = centralIntensity[2];

Answer 2

对于Vec3b，你可以这样做，

Mat image = imread("img_Path");
for(int y=0;y<img.rows;y++)
{
   for(int x=0;x<img.cols;x++)
   {
      // get pixel
      Vec3b color = image.at<Vec3b>(x, y);

      //color.val[0] // B
      //color.val[1] // G
      //color.val[2] // R
   }
}

在OpenCV Mat图像

2 个答案: