截取图中上方数码管中的数字

基本思路：

1、将图像转化为灰度图

2、截取ROI区域

3、二值化

4、循环遍历每一行和每一列，得到字符的坐标

5、截取并保存

1 #include 
     
        2 #include 
      
         3 #include 
       
          4 #include 
        
           5   6 using namespace cv;  7 using namespace std;  8   9  10 int getColSum(Mat& src, int t); 11 int getRowSum(Mat& src, int t); 12 void cutLeft(Mat& src, Mat& leftImg, Mat& rightImg); 13 void cutTop(Mat& src, Mat& dstImg); 14  15 int main() 16 { 17     Mat src = imread("数字.jpg", 0); 18     threshold(src, src, 0, 255, THRESH_BINARY|THRESH_OTSU); 19     imshow("origin", src); 20  21      22      23     Mat roi = src(Rect(250, 25, src.cols-350, 300));//截取ROI区域 24     imshow("ROI", roi); 25     //形态学操作去除干扰 26     Mat kernel = getStructuringElement(MORPH_RECT, Size(7, 7), Point(-1, -1)); 27     morphologyEx(roi, roi, MORPH_OPEN, kernel); 28  29     Mat kernel2 = getStructuringElement(MORPH_RECT, Size(7,7), Point(-1, -1)); 30     dilate(roi, roi, kernel2); 31     imshow("ROI", roi); 32  33     Mat leftImg, rightImg; 34          35     rightImg = roi.clone(); 36     string nameLeft[5] = {
   "digital_1.jpg","digital_2.jpg" ,"digital_3.jpg" ,"digital_4.jpg" ,"digital_5.jpg" }; 37     for (int i = 0; i < 5; i++) { 38  39         cutLeft(rightImg, leftImg, rightImg);         40         imwrite(nameLeft[i], leftImg);//保存 41     } 42  43      44  45     waitKey(0); 46     return 0; 47 } 48 //函数作用：计算某一列的像素和 49 //输入为二值图像 50 int getColSum(Mat& src, int t) { 51     int rowNumber = src.rows;//行数 52     int colNumber = src.cols;//列数 53     uchar ColSum = 0; 54     for (int i = 0; i < rowNumber; i++) 55     { 56         for (int j = 0; j < colNumber; j++) 57         { 58             if (j == t)  59             { 60  61                 ColSum += src.at
         
          (i, j); 62             } 63  64         } 65     } 66     return ColSum; 67 } 68  69 int getRowSum(Mat& src, int t) { 70     int rowNumber = src.rows;//行数 71     int colNumber = src.cols;//列数 72     uchar RowSum = 0; 73     for (int i = 0; i < rowNumber; i++) 74     { 75         if (i== t) 76         { 77  78             for (int j = 0; j < colNumber; j++) 79             { 80  81                 RowSum += src.at
          
           (i, j); 82 83 84 } 85 } 86 } 87 return RowSum; 88 } 89 void cutLeft(Mat& src, Mat& leftImg, Mat& rightImg)//左右切割 90 { 91 int left, right; 92 left = 0; 93 right = src.cols; 94 95 //循环遍历每一列，记录下左端的坐标 96 int i; 97 for (i = 0; i < src.cols; i++) 98 { 99 int colValue = getColSum(src, i);100 //cout <
           <<" th "<< colValue << endl;101 if (colValue > 0)102 {103 left = i;104 break;105 }106 } 107 108 //接着循环遍历每一列，记录下右端的坐标109 for (; i < src.cols; i++)110 {111 int colValue = getColSum(src, i);112 //cout << i << " th " << colValue << endl;113 if (colValue == 0)114 {115 right = i;116 break;117 }118 }119 120 121 int width = right - left;//计算字符的宽度122 123 Rect rect(left, 0, width, src.rows);124 leftImg = src(rect);125 Rect rectRight(right, 0, src.cols - right, src.rows);126 rightImg = src(rectRight);127 cutTop(leftImg, leftImg);128 129 }130 131 void cutTop(Mat& src, Mat& dstImg)//上下切割132 {133 int top, bottom;134 top = 0;135 bottom = src.rows;136 137 int i;138 for (i = 0; i < src.rows; i++)139 {140 int colValue = getRowSum(src, i);141 //cout <<<" th "<< colValue << endl;142 if (colValue > 0)143 {144 top = i;145 break;146 }147 }148 for (; i < src.rows; i++)149 {150 int colValue = getRowSum(src, i);151 //cout << i << " th " << colValue << endl;152 if (colValue == 0)153 {154 bottom = i;155 break;156 }157 }158 159 int height = bottom - top;160 Rect rect(0, top, src.cols, height);161 dstImg = src(rect);162 }