对于需要确定拟合线段(哪几个线段进行拟合)或者目标提取,常常用到投影法。
#include<opencv2\opencv.hpp>
#include<stdio.h>
using namespace cv;
Mat VerticalProjection(Mat srcImage)//垂直积分投影
{
if (srcImage.channels() > 1)
cvtColor(srcImage, srcImage, CV_RGB2GRAY);
Mat srcImageBin;
threshold(srcImage, srcImageBin, 120, 255, CV_THRESH_BINARY_INV);
imshow("二值图", srcImageBin);
int *colswidth = new int[srcImage.cols]; //申请src.image.cols个int型的内存空间
memset(colswidth, 0, srcImage.cols * 4); //数组必须赋初值为零,否则出错。无法遍历数组。
// memset(colheight,0,src->width*4);
// CvScalar value;
int value;
for (int i = 0; i < srcImage.cols; i++)
for (int j = 0; j < srcImage.rows; j++)
{
//value=cvGet2D(src,j,i);
value = srcImageBin.at<uchar>(j, i);
if (value == 255)
{
colswidth[i]++; //统计每列的白色像素点
}
}
Mat histogramImage(srcImage.rows, srcImage.cols, CV_8UC1);
for (int i = 0; i < srcImage.rows; i++)
for (int j = 0; j < srcImage.cols; j++)
{
value = 255; //背景设置为白色。
histogramImage.at<uchar>(i, j) = value;
}
for (int i = 0; i < srcImage.cols; i++)
for (int j = 0; j < colswidth[i]; j++)
{
value = 0; //直方图设置为黑色
histogramImage.at<uchar>(srcImage.rows - 1 - j, i) = value;
}
imshow(" 垂直积分投影图", histogramImage);
return histogramImage;
}
Mat HorizonProjection(Mat srcImage)//水平积分投影
{
if (srcImage.channels() > 1)
cvtColor(srcImage, srcImage, CV_RGB2GRAY);
Mat srcImageBin;
threshold(srcImage, srcImageBin, 120, 255, CV_THRESH_BINARY_INV);
imshow("二值图", srcImageBin);
int *rowswidth = new int[srcImage.rows]; //申请src.image.rows个int型的内存空间
memset(rowswidth, 0, srcImage.rows * 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<srcImage.rows; i++)
for (int j = 0; j<srcImage.cols; j++)
{
//value=cvGet2D(src,j,i);
value = srcImageBin.at<uchar>(i, j);
if (value == 255)
{
rowswidth[i]++; //统计每行的白色像素点
}
}
Mat histogramImage(srcImage.rows, srcImage.cols, CV_8UC1);
for (int i = 0; i<srcImage.rows; i++)
for (int j = 0; j<srcImage.cols; j++)
{
value = 255; //背景设置为白色。
histogramImage.at<uchar>(i, j) = value;
}
//imshow("d", histogramImage);
for (int i = 0; i<srcImage.rows; i++)
for (int j = 0; j<rowswidth[i]; j++)
{
value = 0; //直方图设置为黑色
histogramImage.at<uchar>(i, j) = value;
}
imshow("水平积分投影图", histogramImage);
delete[] rowswidth;//释放前面申请的空间
return histogramImage;
}