OpenCV(Cpp) Segmentation and Labeling - minho0315/OpenCV GitHub Wiki
์ด๋ฏธ์ง ์ ๋ช ํ๋ฅผ ์ํด filter2D ์ฌ์ฉ
์ด์ง ์ด๋ฏธ์ง์ ํ์ ํํ์ ์ป๊ธฐ ์ํด distanceTransform ์ฌ์ฉ
watershed ๋ฅผ ์ฌ์ฉํ์ฌ ์ด๋ฏธ์ง์ ๊ฐ์ฒด๋ฅผ ๋ฐฐ๊ฒฝ์์ ๋ถ๋ฆฌ
์ค์ต ์ฝ๋
#include <opencv2/core.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/highgui.hpp>
#include <iostream>
using namespace std;
using namespace cv;
int main(int argc, char* argv[])
{
// Load the image
Mat src = imread("coin.jpg");
if (src.empty())
{
cout << "Could not open or find the image!\n" << endl;
cout << "Usage: " << argv[0] << " <Input image>" << endl;
return -1;
}
// Show source image
imshow("Source Image", src);
// ๋์ค์ ์ถ์ถํ๋๋ฐ ๋์์ด๋๋ฏ๋ก ๋ฐฐ๊ฒฝ์ ํฐ์์ฃ ๊ฒ์ ์์ผ๋ก ๋ณ๊ฒฝ
for (int i = 0; i < src.rows; i++) {
for (int j = 0; j < src.cols; j++) {
if (src.at<Vec3b>(i, j) == Vec3b(255, 255, 255))
{
src.at<Vec3b>(i, j)[0] = 0;
src.at<Vec3b>(i, j)[1] = 0;
src.at<Vec3b>(i, j)[2] = 0;
}
}
}
// Show output image
imshow("Black Background Image", src);
// ์ด๋ฏธ์ง๋ฅผ ์ ๋ช
ํ๊ฒํ๋ ๋ฐ ์ฌ์ฉํ ์ปค๋์ ๋ง๋ ๋ค.
Mat kernel = (Mat_<float>(3, 3) <<
1, 1, 1,
1, -8, 1,
1, 1, 1); // an approximation of second derivative, a quite strong kernel
// do the laplacian filtering as it is
// well, we need to convert everything in something more deeper then CV_8U
// because the kernel has some negative values,
// and we can expect in general to have a Laplacian image with negative values
// BUT a 8bits unsigned int (the one we are working with) can contain values from 0 to 255
// so the possible negative number will be truncated
Mat imgLaplacian;
filter2D(src, imgLaplacian, CV_32F, kernel);
Mat sharp;
src.convertTo(sharp, CV_32F);
Mat imgResult = sharp - imgLaplacian;
// convert back to 8bits gray scale
imgResult.convertTo(imgResult, CV_8UC3);
imgLaplacian.convertTo(imgLaplacian, CV_8UC3);
// imshow( "Laplace Filtered Image", imgLaplacian );
imshow("New Sharped Image", imgResult);
// Create binary image from source image
Mat bw;
cvtColor(imgResult, bw, COLOR_BGR2GRAY);
threshold(bw, bw, 40, 255, THRESH_BINARY | THRESH_OTSU);
imshow("Binary Image", bw);
// Perform the distance transform algorithm
Mat dist;
distanceTransform(bw, dist, DIST_L2, 3);
// Normalize the distance image for range = {0.0, 1.0}
// so we can visualize and threshold it
normalize(dist, dist, 0, 1.0, NORM_MINMAX);
imshow("Distance Transform Image", dist);
// Threshold to obtain the peaks
// This will be the markers for the foreground objects
threshold(dist, dist, 0.4, 1.0, THRESH_BINARY);
// Dilate a bit the dist image
Mat kernel1 = Mat::ones(3, 3, CV_8U);
dilate(dist, dist, kernel1);
imshow("Peaks", dist);
// Create the CV_8U version of the distance image
// It is needed for findContours()
Mat dist_8u;
dist.convertTo(dist_8u, CV_8U);
// Find total markers
vector<vector<Point> > contours;
findContours(dist_8u, contours, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
// Create the marker image for the watershed algorithm
Mat markers = Mat::zeros(dist.size(), CV_32S);
// Draw the foreground markers
for (size_t i = 0; i < contours.size(); i++)
{
drawContours(markers, contours, static_cast<int>(i), Scalar(static_cast<int>(i) + 1), -1);
}
// Draw the background marker
circle(markers, Point(5, 5), 3, Scalar(255), -1);
imshow("Markers", markers * 10000);
// Perform the watershed algorithm
watershed(imgResult, markers);
Mat mark;
markers.convertTo(mark, CV_8U);
bitwise_not(mark, mark);
imshow("Markers_v2", mark); // uncomment this if you want to see how the mark
// image looks like at that point
// Generate random colors
vector<Vec3b> colors;
for (size_t i = 0; i < contours.size(); i++)
{
int b = theRNG().uniform(0, 256);
int g = theRNG().uniform(0, 256);
int r = theRNG().uniform(0, 256);
colors.push_back(Vec3b((uchar)b, (uchar)g, (uchar)r));
}
// Create the result image
Mat dst = Mat::zeros(markers.size(), CV_8UC3);
// Fill labeled objects with random colors
for (int i = 0; i < markers.rows; i++)
{
for (int j = 0; j < markers.cols; j++)
{
int index = markers.at<int>(i, j);
if (index > 0 && index <= static_cast<int>(contours.size()))
{
dst.at<Vec3b>(i, j) = colors[index - 1];
}
}
}
// Visualize the final image
imshow("Final Result", dst);
waitKey();
return 0;
}
๊ฒฐ๊ณผ
์ฝ๋
https://docs.opencv.org/3.4.12/d2/dbd/tutorial_distance_transform.html
์ด๋ฏธ์ง
๋ ์ด๋ธ๋ง( labeling ) ์ด๋?
์ธ์ ํ ๊ฐ์ ๊ฐ์ ๊ฐ๋ ํฝ์ ๋ผ๋ฆฌ ํ๋์ ๊ทธ๋ฃน์ผ๋ก ๋ฌถ์ด์ฃผ๋ ์์ ์ด๋ค.
์ฝ๊ฒ ๋งํด์ ์ด์งํ ์ด๋ฏธ์ง์์ ๊ฒฝ๊ณ๋ฅผ ์ด๋ฃฌ ์์ญ์ ์ด๋ฆ(์ซ์)์ ๋ถ์ฌํ๋ ์์ ์ด๋ค.
์ค์ต ์ฝ๋
#include <opencv2/opencv.hpp>
#include <windows.h>
using namespace cv;
using namespace std;
int main(int ac, char** av)
{
Mat img = imread("bacteria.tif");
Mat img_resize;
resize(img, img_resize, Size(img.cols * 3, img.rows * 3));
Mat img_gray;
cvtColor(img_resize, img_gray, COLOR_BGR2GRAY);
Mat img_threshold;
threshold(img_gray, img_threshold, 100, 255, THRESH_BINARY_INV);
Mat img_labels, stats, centroids;
int numOfLables = connectedComponentsWithStats(img_threshold, img_labels, stats, centroids, 8, CV_32S);
// ๋ ์ด๋ธ๋ง ๊ฒฐ๊ณผ์ ์ฌ๊ฐํ ๊ทธ๋ฆฌ๊ณ , ๋๋ฒ ํ์ํ๊ธฐ
for (int j = 1; j < numOfLables; j++) {
int area = stats.at<int>(j, CC_STAT_AREA);
int left = stats.at<int>(j, CC_STAT_LEFT);
int top = stats.at<int>(j, CC_STAT_TOP);
int width = stats.at<int>(j, CC_STAT_WIDTH);
int height = stats.at<int>(j, CC_STAT_HEIGHT);
rectangle(img_resize, Point(left, top), Point(left + width, top + height),
Scalar(0, 0, 255), 1);
putText(img_resize, to_string(j), Point(left + 20, top + 20), FONT_HERSHEY_SIMPLEX, 1, Scalar(255, 0, 0), 1);
}
imshow("img_resize", img_resize);
cout << "numOfLables : " << numOfLables - 1 << endl; // ์ต์ข
๋๋ฒ๋ง์์ 1์ ๋นผ์ค์ผ ํจ
waitKey(0);
return 0;
}
๊ฒฐ๊ณผ