OpenCV图片连通域数量 使用OpenCV获取图片连通域数量,并用不同颜色标记函
业余狙击手19 人气:0一,原图和效果图
二,代码
//#########################产生随机颜色######################### cv::Scalar icvprGetRandomColor() { uchar r = 255 * (rand() / (1.0 + RAND_MAX)); uchar g = 255 * (rand() / (1.0 + RAND_MAX)); uchar b = 255 * (rand() / (1.0 + RAND_MAX)); return cv::Scalar(b, g, r); } //#########################产生随机颜色######################### //########################种子填充法)######################### void ConnectedCountBySeedFill(const cv::Mat& _binImg, cv::Mat& _lableImg, int &iConnectedAreaCount) { //拓宽1个像素的原因是:如果连通域在边缘,运行此函数会异常崩溃,所以需要在周围加一圈0值,确保连通域不在边上 //==========图像周围拓宽1个像素============================================ int top, bottom; //【添加边界后的图像尺寸】 int leftImage, rightImage; int borderType = BORDER_CONSTANT; //BORDER_REPLICATE //【初始化参数】 top = (int)(1); bottom = (int)(1); leftImage = (int)(1); rightImage = (int)(1); Mat _binImg2, _binImg3; _binImg.copyTo(_binImg2); //初始化参数value Scalar value(0); //填充值 //创建图像边界 copyMakeBorder(_binImg2, _binImg3, top, bottom, leftImage, rightImage, borderType, value); //==========图像周围拓宽1个像素============================================ // connected component analysis (4-component) // use seed filling algorithm // 1. begin with a foreground pixel and push its foreground neighbors into a stack; // 2. pop the top pixel on the stack and label it with the same label until the stack is empty // // foreground pixel: _binImg(x,y) = 1 // background pixel: _binImg(x,y) = 0 if (_binImg3.empty() || _binImg3.type() != CV_8UC1) { return; } _lableImg.release(); _binImg3.convertTo(_lableImg, CV_32SC1); int icount = 0; int label = 1; // start by 2 int rows = _binImg3.rows - 1; int cols = _binImg3.cols - 1; for (int i = 1; i < rows - 1; i++) { int* data = _lableImg.ptr<int>(i); //取一行数据 for (int j = 1; j < cols - 1; j++) { if (data[j] == 1) //像素不为0 { std::stack<std::pair<int, int>> neighborPixels; //新建一个栈 neighborPixels.push(std::pair<int, int>(i, j)); // 像素坐标: <i,j> ,以该像素为起点,寻找连通域 ++label; // 开始一个新标签,各连通域区别的标志 while (!neighborPixels.empty()) { // 获取堆栈中的顶部像素并使用相同的标签对其进行标记 std::pair<int, int> curPixel = neighborPixels.top(); int curX = curPixel.first; int curY = curPixel.second; _lableImg.at<int>(curX, curY) = label; //对图像对应位置的点进行标记 // 弹出顶部像素 (顶部像素出栈) neighborPixels.pop(); // 加入8邻域点 if (_lableImg.at<int>(curX, curY - 1) == 1) {// 左点 neighborPixels.push(std::pair<int, int>(curX, curY - 1)); //左边点入栈 } if (_lableImg.at<int>(curX, curY + 1) == 1) {// 右点 neighborPixels.push(std::pair<int, int>(curX, curY + 1)); //右边点入栈 } if (_lableImg.at<int>(curX - 1, curY) == 1) {// 上点 neighborPixels.push(std::pair<int, int>(curX - 1, curY)); //上边点入栈 } if (_lableImg.at<int>(curX + 1, curY) == 1) {// 下点 neighborPixels.push(std::pair<int, int>(curX + 1, curY)); //下边点入栈 } //===============补充到8连通域====================================================== if (_lableImg.at<int>(curX - 1, curY - 1) == 1) {// 左上点 neighborPixels.push(std::pair<int, int>(curX - 1, curY - 1)); //左上点入栈 } if (_lableImg.at<int>(curX - 1, curY + 1) == 1) {// 右上点 neighborPixels.push(std::pair<int, int>(curX - 1, curY + 1)); //右上点入栈 } if (_lableImg.at<int>(curX + 1, curY - 1) == 1) {// 左下点 neighborPixels.push(std::pair<int, int>(curX + 1, curY - 1)); //左下点入栈 } if (_lableImg.at<int>(curX + 1, curY + 1) == 1) {// 右下点 neighborPixels.push(std::pair<int, int>(curX + 1, curY + 1)); //右下点入栈 } //===============补充到8连通域====================================================== } } } } iConnectedAreaCount = label - 1; //因为label从2开始计数的 int a = 0; } ########################################################### //#############添加颜色##################################### Mat PaintColor(Mat src, int iConnectedAreaCount) { int rows = src.rows; int cols = src.cols; //cv::Scalar(b, g, r); std::map<int, cv::Scalar> colors; for (int n = 1; n <= iConnectedAreaCount + 1; n++) { colors[n] = icvprGetRandomColor(); //根据不同标志位产生随机颜色 cv::Scalar color = colors[n]; int a = color[0]; int b = color[1]; int c = color[2]; int d = 0; } Mat dst2(rows, cols, CV_8UC3); dst2 = cv::Scalar::all(0); for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { int value = src.at<int>(i, j); if (value>1) { cv::Scalar color = colors[value]; int a = color[0]; int b = color[1]; int c = color[2]; dst2.at<Vec3b>(i, j)[0] = color[0]; dst2.at<Vec3b>(i, j)[1] = color[1]; dst2.at<Vec3b>(i, j)[2] = color[2]; } } } return dst2; } //#############添加颜色################################## //########调用########################################## Mat binImage = cv::imread("D:\\sxl\\处理图片\\testImages\\22.jpg", 0); threshold(binImage, binImage, 50, 1, CV_THRESH_BINARY_INV); // 连通域标记 Mat labelImg; int iConnectedAreaCount = 0; //连通域个数 ConnectedCountBySeedFill(binImage, labelImg, iConnectedAreaCount);//针对黑底白字 int a=iConnectedAreaCount; // 显示结果 Mat dstColor2=PaintColor(labelImg,iConnectedAreaCount); imshow("colorImg", dstColor2); Mat grayImg; labelImg *= 10; labelImg.convertTo(grayImg, CV_8UC1); imshow("labelImg", grayImg); waitKey(0); //########调用##########################################
补充知识:Opencv快速获取连通域
对于ndarray数据中的连通域查找,opencv提供了接口,非常方便。
import cv2 import numpy as np img = np.array([ [0, 255, 255, 0, 0, 0, 255, 255,], [0, 0, 255, 0, 255, 255, 255, 0], [0, 0, 0, 0, 255, 255, 0, 255], [255, 255, 0, 0, 0, 0, 0, 0], [255, 255, 0, 0, 0, 0, 0, 0], [255, 255, 0, 0, 0, 0, 0, 0] ], dtype=np.uint8) num, labels = cv2.connectedComponents(img) labels_dict = {i:[] for i in range(1, num+1)} height, width = img.shape for h in range(height): for w in range(width): if labels[h][w] in labels_dict: labels_dict[labels[h][w]].append([h,w])
cv2.connectedComponents()函数返回查找到的连通域个数和对应的label。
上面代码返回连通域个数为4(包含值为0区域,可通过lables过滤), labels结果如图所示:
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