机器视觉-笔试题2 统计直方图

不允许用opencv的Mat，要求手写代码；
  1 #include<iostream>
  2 #include<vector>
  3 using namespace std;
  4 
  5 //随机数头文件
  6 #include <stdlib.h> 
  7 #include <stdio.h> 
  8 #include <time.h> 
  9 
 10 
 11 
 12 #define MAX_PIXEL_VALUE 25
 13 
 14 namespace MY
 15 {
 16     class Mat
 17     {
 18     public:
 19         Mat();
 20         Mat(int rows, int cols);
 21         int rows() const
 22         {
 23             return rows_;
 24         }
 25         int cols() const
 26         {
 27             return cols_;
 28         }
 29         ~Mat();
 30         bool empty() const
 31         {
 32             return image.empty();
 33         }
 34         int get(int rows, int cols) const
 35         {
 36             return image[rows][cols];
 37         }
 38     public:vector<vector<int>> image;
 39     private:
 40         int rows_;
 41         int cols_;
 42     };
 43     Mat::Mat(int rows, int cols) :rows_(rows), cols_(cols)
 44     {
 45         srand((unsigned)time(NULL));//随机数种子
 46         for (int j = 0; j < rows; j++)
 47         {
 48             vector<int> temp;
 49             for (int i = 0; i < cols; i++)
 50             {
 51                 temp.push_back(rand() % (MAX_PIXEL_VALUE+1));//【0，26)
 52             }
 53             image.push_back(temp);
 54         }
 55     }
 56     Mat::Mat()
 57     {
 58     }
 59 
 60     Mat::~Mat()
 61     {
 62     }
 63     
 64     //统计直方图
 65     void ImHist(const vector<vector<int>>& vecs)
 66     {
 67         if (vecs.empty())
 68         {
 69             cout << "empty! " << endl;
 70             return;
 71         }
 72         else
 73         {
 74             int rows = vecs.size();
 75             int cols = vecs[0].size();
 76             vector<int> imhist((MAX_PIXEL_VALUE + 1), 0);
 77             for (int j = 0; j < rows; j++)
 78             {
 79                 for (int i = 0; i < cols; i++)
 80                 {
 81                     imhist[vecs[j][i]]++;
 82                 }
 83             }
 84             // 直方图，控制台显示
 85             for(auto& pixelvalue:imhist)
 86             {
 87                 for (int i = 0; i < pixelvalue; i++)
 88                 {
 89                     cout << "-";
 90                 }
 91                 cout << endl;
 92             }
 93         }
 94     }
 95     //显示Mat
 96     void PrintMat(const Mat& mat) //const 对象只能访问const成员函数
 97     {
 98         if (mat.empty())
 99         {
100             cout << "empty! " << endl;
101             return;
102         }
103         else
104         {
105             for (int j = 0; j < mat.rows(); j++)
106             {
107                 for (int i = 0; i < mat.cols(); i++)
108                 {
109                     cout << mat.get(j,i) << " ";
110                     cout.width(2);
111                 }
112                 cout << endl;
113             }
114         }
115 
116     }
117 }
118 
119 
120 int main()
121 {
122     MY::Mat matrix(30, 30);
123     vector<vector<int>> image = matrix.image;
124     MY::PrintMat(matrix);
125     MY::ImHist(image);
126     return 1;
127 }
凑合显示下直方图