opencv检测直线方法之投影法

#include<iostream> 
#include<vector>
#include <cv.h> 
#include <highgui.h>
using namespace std;
using namespace cv;
Mat VerticalLine(Mat srcImageBin)//垂直线条检测 
{
 
 vector <int> array;//动态数组用来存储投影值大于阈值的横坐标
 
 int *colswidth = new int[srcImageBin.cols]; //申请src.image.cols个int型的内存空间，存储二值图中每列的白色像素数 
 memset(colswidth, 0, srcImageBin.cols * 4); //数组必须赋初值为零，否则出错。无法遍历数组。 
 
 int value;
 for (int i = 0; i < srcImageBin.cols; i++)
 {
 
 for (int j = 0; j < srcImageBin.rows; j++)
 {
 value = srcImageBin.at<uchar>(j, i);
 
 if (value == 255)
 {
 colswidth[i]++; //统计每列的白色像素点 
 
 }
 
 }
 
 }
 
 Mat lineImage(srcImageBin.rows, srcImageBin.cols, CV_8UC1, cv::Scalar(0, 0, 0));
 
 //寻找投影大于阈值0.3*srcImageBin.rows的横坐标
 for (int i = 0; i < srcImageBin.cols; i++)
 {
 bool flag = true;
 
 for (int j = 0; j < colswidth[i] && colswidth[i] >= (0.3*srcImageBin.rows); j++)
 {
 
 if (flag == true)
 {
 array.push_back(i);
 flag = false;
 }
 }
 }
 int count = array.size();
 //恢复直线
 for (int n = 0; n < srcImageBin.rows; n++)
 {
 for (int w = 0; w<count; w++)
 {
 if (srcImageBin.at<uchar>(n, array[w]) == 255)
 {
 lineImage.at<uchar>(n, array[w]) = 255;
 }
 
 }
 }
 
 
 
 delete[] colswidth;
 return lineImage;
}
Mat HorizonLine(Mat srcImageBin)//水平线条检测
{
 vector <int> array1;
 
 int *rowswidth = new int[srcImageBin.rows]; 
 memset(rowswidth, 0, srcImageBin.rows * 4); 
 int value;
 for (int i = 0; i < srcImageBin.rows; i++)
 {
 for (int j = 0; j < srcImageBin.cols; j++)
 {
 value = srcImageBin.at<uchar>(i, j);
 if (value == 255)
 {
 rowswidth[i]++; //统计每行的白色像素点 
 }
 }
 
 }
 
 Mat lineImage(srcImageBin.rows, srcImageBin.cols, CV_8UC1, cv::Scalar(0, 0, 0));
 
 //寻找投影大于阈值0.525*srcImageBin.cols的纵坐标
 for (int i = 0; i < srcImageBin.rows; i++)
 {
 bool flag = true;
 for (int j = 0; j < rowswidth[i] && rowswidth[i] >= (0.525*srcImageBin.cols); j++)
 {
 if (flag == true)
 {
 array1.push_back(i);
 flag = false;
 }
 
 }
 }
 int count = array1.size();
 
 //恢复水平线
 for (int h = 0; h<count; h++)
 {
 for (int m = 0; m < srcImageBin.cols; m++)
 {
 if (srcImageBin.at<uchar>(array1[h], m) == 255)
 {
 lineImage.at<uchar>(array1[h], m) = 255;
 }
 
 }
 }
 
 
 delete[] rowswidth;//释放前面申请的空间 
 return lineImage;
}
int main()
{
 Mat srcImage = imread("E:\\x.jpg");
 Mat closeimage;
 imshow("原图", srcImage);
 if (srcImage.channels() > 1)
 cvtColor(srcImage, srcImage, CV_RGB2GRAY);
 Mat srcImageBin;
 threshold(srcImage, srcImageBin, 140, 255, CV_THRESH_OTSU | CV_THRESH_BINARY_INV);
 
 Mat VP;
 VP = VerticalLine(srcImageBin);
 
 Mat HP;
 HP = HorizonLine(srcImageBin);
 
 Mat mergelineImage;
 
 bitwise_or(HP, VP, mergelineImage);
 imshow("mergelineImage", mergelineImage);
 
 waitKey(0);
 return 0;
 
}