OpenCV连通域数量统计学习示例

Karli ·

更新时间:2024-09-21

· 1455 次阅读

学习目标：

核心代码

代码执行说明

学习目标：

1.输入图像为分割结果图像

2.根据种子填充法思路，遍历图像，得到每个连通域外接矩形坐标信息、面积信息

核心代码

/*
Input:
src: 待检测连通域的二值化图像
Output:
dst: 标记后的图像
featherList: 连通域特征的清单（可自行查阅文档）
return：
连通域数量。
*/
int connectionDetect(Mat &src, Mat &dst, vector<Feather> &featherList)
{
int rows = src.rows;
int cols = src.cols;
int labelValue = 0;
Point seed, neighbor;
stack<Point> pointStack;
// 用于计算连通域的面积
int area = 0;         
// 连通域的左边界，即外接最小矩形的左边框，横坐标值，依此类推
int leftBoundary = 0;       
int rightBoundary = 0;
int topBoundary = 0;
int bottomBoundary = 0;
// 外接矩形框
Rect box;                   
Feather feather;
vector<stack<Point>> points;
featherList.clear();
dst.release();
dst = src.clone();
for (int i = 0; i < rows; i++)
{
uchar *pRow = dst.ptr<uchar>(i);
for (int j = 0; j < cols; j++)
{
if (pRow[j] == 255)
{
area = 0;
// labelValue最大为254，最小为1.
labelValue++;       
// Point（横坐标，纵坐标）
seed = Point(j, i);     
dst.at<uchar>(seed) = labelValue;
pointStack.push(seed);
area++;
leftBoundary = seed.x;
rightBoundary = seed.x;
topBoundary = seed.y;
bottomBoundary = seed.y;
while (!pointStack.empty())
{
neighbor = Point(seed.x + 1, seed.y);
if ((seed.x != (cols - 1)) && (dst.at<uchar>(neighbor) == 255))
{
dst.at<uchar>(neighbor) = labelValue;
pointStack.push(neighbor);
area++;
if (rightBoundary < neighbor.x)
rightBoundary = neighbor.x;
}
neighbor = Point(seed.x, seed.y + 1);
if ((seed.y != (rows - 1)) && (dst.at<uchar>(neighbor) == 255))
{
dst.at<uchar>(neighbor) = labelValue;
pointStack.push(neighbor);
area++;
if (bottomBoundary < neighbor.y)
bottomBoundary = neighbor.y;
}
neighbor = Point(seed.x - 1, seed.y);
if ((seed.x != 0) && (dst.at<uchar>(neighbor) == 255))
{
dst.at<uchar>(neighbor) = labelValue;
pointStack.push(neighbor);
area++;
if (leftBoundary > neighbor.x)
leftBoundary = neighbor.x;
}
neighbor = Point(seed.x, seed.y - 1);
if ((seed.y != 0) && (dst.at<uchar>(neighbor) == 255))
{
dst.at<uchar>(neighbor) = labelValue;
pointStack.push(neighbor);
area++;
if (topBoundary > neighbor.y)
topBoundary = neighbor.y;
}
seed = pointStack.top();
pointStack.pop();
}
box = Rect(leftBoundary, topBoundary, rightBoundary - leftBoundary, bottomBoundary - topBoundary);
feather.area = area;
feather.boundingbox = box;
feather.label = labelValue;
featherList.push_back(feather);
}
}
}
return labelValue;
}

代码执行说明

<font color=#999AAA >在此不进行实例演示

1、输入图像为分割后图像

2、执行结果可根据featherList信息自行绘制矩形框