学OpenCV

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这里的行列对应y和x。

 

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 1 #include <iostream>
 2 
 3 #include <opencv2/opencv.hpp>
 4 #include <opencv2/core/utils/logger.hpp>
 5 
 6 
 7 void Test1()
 8 {
 9     float arr[] = { 1,2,3,4,
10                     5,6,7,8,
11                     9,10,11,12 };
12     cv::Mat img(3,4,CV_32FC1,arr);
13 
14     double min, max;
15     cv::Point posmin, posmax;
16     cv::minMaxLoc(img, &min, &max, &posmin, &posmax);
17     std::cout << "Test1 min:" << min << std::endl;
18     std::cout << "Test1 max:" << max << std::endl;
19     std::cout << "Test1 posmin:" << posmin << " row=" << posmin.y<<",col=" << posmin.x << std::endl;
20     std::cout << "Test1 posmax:" << posmax <<"  row=" << posmax.y << ",col=" << posmax.x << std::endl;
21 }
22 
23 template <typename T>
24 T* MakeArrInSerial(int datasize)
25 {
26     T* ptr = new T[datasize];
27     for (int i = 0; i < datasize; i++)
28     {
29         ptr[i] = (T)i;
30     }
31     return ptr;
32 }
33 
34 
35 void Test2()
36 {
37     float* arr = MakeArrInSerial<float>(36);
38     cv::Mat img(3, 4, CV_32FC3, arr);
39 
40     double min, max;
41     cv::Point posmin, posmax;
42 
43     cv::Mat imgc1=img.reshape(1);
44     cv::minMaxLoc(imgc1, &min, &max, &posmin, &posmax);
45     std::cout << "Test2 min:" << min << std::endl;
46     std::cout << "Test2 max:" << max << std::endl;
47     std::cout << "Test2 posmin:" << posmin << " row=" << posmin.y << ",col=" << posmin.x << std::endl;
48     std::cout << "Test2 posmax:" << posmax << "  row=" << posmax.y << ",col=" << posmax.x << std::endl;
49 }
50 
51 int main()
52 {
53     cv::utils::logging::setLogLevel(cv::utils::logging::LOG_LEVEL_ERROR);
54     
55     Test1();
56     Test2();
57 
58     cv::waitKey(0);
59 
60     return 0;
61 }

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结果

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这里的reshape函数，虽然有3个重载，但似乎只有1个用起来方便，其他的没成功。

 1 #include <iostream>
 2 
 3 #include <opencv2/opencv.hpp>
 4 #include <opencv2/core/utils/logger.hpp>
 5 
 6 
 7 template <typename T>
 8 T* MakeSerialArr(int datasize)
 9 {
10     T* ptr = new T[datasize];
11     for (int i = 0; i < datasize; i++)
12     {
13         ptr[i] = (T)i;
14     }
15     return ptr;
16 }
17 
18 #define SerialArr_Heap(name,type,size) \
19     type* name = new type[size];\
20     for (int i = 0; i < size; i++) \
21     {\
22         name[i] = (type)i;\
23     }
24 
25 #define SerialArr_Stack(name,type,size) \
26     type name[size]={};\
27     for (int i = 0; i < size; i++) \
28     {\
29         name[i] = (type)i;\
30     }
31 
32 
33 void Test1()
34 {
35     SerialArr_Stack(arr,int,5*6*3)
36     cv::Mat m1(5, 6, CV_32SC3, arr);
37     cv::Mat m11=m1.reshape(2);
38     cv::Mat m12 = m1.reshape(2, 3);
39 
40     //cv::Mat m12 = m1.reshape(2,4);
41     //如果不能整除，那么会报异常。
42     //OpenCV(4.10.0) Error: Bad argument (The total number of matrix elements is not divisible by the new number of rows) 
43     // in cv::Mat::reshape, file C:\GHA-OCV-1\_work\ci-gha-workflow\ci-gha-workflow\opencv\modules\core\src\matrix.cpp, 
44     // line 1183
45 }
46 
47 void Test2()
48 {
49     SerialArr_Stack(arr, int, 5 * 6 * 3);
50     cv::Mat m1(5, 6, CV_32SC3, arr);
51     //cv::Mat m11 = m1.reshape(3,std::vector<int>(6,5));
52 
53     //OpenCV(4.10.0) Error: Sizes of input arguments do not match (Requested and source matrices have different count of elements) 
54     // in cv::Mat::reshape, file C:\GHA-OCV-1\_work\ci-gha-workflow\ci-gha-workflow\opencv\modules\core\src\matrix.cpp, 
55     // line 1240
56 }
57 
58 void Test3()
59 {
60     SerialArr_Stack(arr, int, 5 * 6 * 3);
61     cv::Mat m1(5, 6, CV_32SC3, arr);
62     int newndims[] = { 2,2 };
63     //cv::Mat m11 = m1.reshape(2, 2, newndims);
64     //cv::Mat m11 = m1.reshape(2,4,newndims);
65     
66     //OpenCV(4.10.0) Error: Sizes of input arguments do not match(Requested and source matrices have different count of elements) 
67     // in cv::Mat::reshape, file C : \GHA - OCV - 1\_work\ci - gha - workflow\ci - gha - workflow\opencv\modules\core\src\matrix.cpp, 
68     // line 1240 
69 }
70 
71 
72 int main()
73 {
74     cv::utils::logging::setLogLevel(cv::utils::logging::LOG_LEVEL_ERROR);
75     
76     Test1();
77     Test2();
78     Test3();
79 
80     cv::waitKey(0);
81 
82     return 0;
83 }