opencv之mat元素访问

 1 #include <stdlib.h>
 2 #include <stdio.h>
 3 #include <opencv/cv.h>
 4 #include <opencv/highgui.h>
 5 #include <opencv2/opencv.hpp>
 6 
 7 using namespace std;
 8 using namespace cv;
 9 int main()
10 {
11     Mat img(3, 4, CV_32FC1, Scalar_<float>(12.625));
12     
13     cout<<img<<endl;
14     cout<<endl;
15     /*cout << "dims:" << img.dims << endl;   
16     cout << "rows:" << img.rows << endl;   
17     cout << "cols:" << img.cols << endl;   
18     cout << "channels:" << img.channels() << endl;
19     
20     cout << "elemSize:" << img.elemSize() << endl;  
21     cout << "elemSize1:" << img.elemSize1() << endl;*/
22 
23     
24 
25     //元素的遍历：
26     for(int row = 0; row < img.rows; row++)
27     {
28         for(int col = 0;col < img.cols; col++)
29         {
30             cout<<img.at<float>(row,col)<<" ";
31         }
32         cout<<endl;
33     }
34     
35     system("pause");
36     return 0;
37 }

 Mat img(3, 4, CV_32FC1, Scalar_<float>(12.625));
3乘4的图片~
Mat_<uchar>对应的是CV_8U，
Mat_<char>对应的是CV_8S，
Mat_<int>对应的是CV_32S，
Mat_<float>对应的是CV_32F，
Mat_<double>对应的是CV_64F，对应的数据深度如下：

Scalar_<**>的**处填上对应的类型！！

 CV_8U - 8-bit unsigned integers ( 0..255 )
 CV_8S - 8-bit signed integers ( -128..127 )
 CV_16U - 16-bit unsigned integers ( 0..65535 )
 CV_16S - 16-bit signed integers ( -32768..32767 )
 CV_32S - 32-bit signed integers ( -2147483648..2147483647 )
 CV_32F - 32-bit ?oating-point numbers ( -FLT_MAX..FLT_MAX, INF, NAN )
 CV_64F - 64-bit ?oating-point numbers ( -DBL_MAX..DBL_MAX, INF, NAN )

因为单通道，所以上例访问元素时候对应写成

img.at<float>(row,col)

...

 1 #include <stdlib.h>
 2 #include <stdio.h>
 3 #include <opencv/cv.h>
 4 #include <opencv/highgui.h>
 5 #include <opencv2/opencv.hpp>
 6 
 7 using namespace std;
 8 using namespace cv;
 9 int main()
10 {
11     Mat img(3, 4, CV_64FC2, Scalar_<double>(12.625,3.141592653));
12     //Mat_(Vec)
13     cout<<img<<endl;
14     cout<<endl;
15     /*cout << "dims:" << img.dims << endl;   
16     cout << "rows:" << img.rows << endl;   
17     cout << "cols:" << img.cols << endl;   
18     cout << "channels:" << img.channels() << endl;
19     
20     cout << "elemSize:" << img.elemSize() << endl;  
21     cout << "elemSize1:" << img.elemSize1() << endl;*/
22 
23 
24     //元素的遍历：
25     for(int row = 0; row < img.rows; row++)
26     {
27         for(int col = 0;col < img.cols; col++)
28         {
29             cout<<img.at<Vec2d>(row,col)[0]<<" "<<img.at<Vec2d>(row,col)[1]<<"\t";
30         }
31         cout<<endl;
32     }
33 
34 
35     system("pause");
36     return 0;
37 }

typedef Vec<uchar, 2> Vec2b;
typedef Vec<uchar, 3> Vec3b;
typedef Vec<uchar, 4> Vec4b;

typedef Vec<short, 2> Vec2s;
typedef Vec<short, 3> Vec3s;
typedef Vec<short, 4> Vec4s;

typedef Vec<ushort, 2> Vec2w;
typedef Vec<ushort, 3> Vec3w;
typedef Vec<ushort, 4> Vec4w;

typedef Vec<int, 2> Vec2i;
typedef Vec<int, 3> Vec3i;
typedef Vec<int, 4> Vec4i;
typedef Vec<int, 6> Vec6i;
typedef Vec<int, 8> Vec8i;

typedef Vec<float, 2> Vec2f;
typedef Vec<float, 3> Vec3f;
typedef Vec<float, 4> Vec4f;
typedef Vec<float, 6> Vec6f;

typedef Vec<double, 2> Vec2d;
typedef Vec<double, 3> Vec3d;
typedef Vec<double, 4> Vec4d;
typedef Vec<double, 6> Vec6d;