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| -rw-r--r-- | watershed.cpp | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/watershed.cpp b/watershed.cpp new file mode 100644 index 0000000..64fe039 --- /dev/null +++ b/watershed.cpp @@ -0,0 +1,95 @@ +/** + * Count and segment overlapping objects with Watershed and Distance Transform. + * + * See the tutorial at: + * http://opencv-code.com/count-and-segment-overlapping-objects-with-watershed-and-distance-transform/ + */ +#include <opencv2/imgproc/imgproc.hpp> +#include <opencv2/highgui/highgui.hpp> +#include <iostream> + +int main() +{ + cv::Mat src = cv::imread("coins.jpg"); + if (!src.data) + return -1; + + cv::imshow("src", src); + + // Create binary image from source image + cv::Mat bw; + cv::cvtColor(src, bw, CV_BGR2GRAY); + cv::threshold(bw, bw, 40, 255, CV_THRESH_BINARY); + cv::imshow("bw", bw); + + // Perform the distance transform algorithm + cv::Mat dist; + cv::distanceTransform(bw, dist, CV_DIST_L2, 3); + + // Normalize the distance image for range = {0.0, 1.0} + // so we can visualize and threshold it + cv::normalize(dist, dist, 0, 1., cv::NORM_MINMAX); + cv::imshow("dist", dist); + + // Threshold to obtain the peaks + // This will be the markers for the foreground objects + cv::threshold(dist, dist, .5, 1., CV_THRESH_BINARY); + cv::imshow("dist2", dist); + + // Create the CV_8U version of the distance image + // It is needed for cv::findContours() + cv::Mat dist_8u; + dist.convertTo(dist_8u, CV_8U); + + // Find total markers + std::vector<std::vector<cv::Point> > contours; + cv::findContours(dist_8u, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE); + int ncomp = contours.size(); + + // Create the marker image for the watershed algorithm + cv::Mat markers = cv::Mat::zeros(dist.size(), CV_32SC1); + + // Draw the foreground markers + for (int i = 0; i < ncomp; i++) + cv::drawContours(markers, contours, i, cv::Scalar::all(i+1), -1); + + // Draw the background marker + cv::circle(markers, cv::Point(5,5), 3, CV_RGB(255,255,255), -1); + cv::imshow("markers", markers*10000); + + // Perform the watershed algorithm + cv::watershed(src, markers); + + // Generate random colors + std::vector<cv::Vec3b> colors; + for (int i = 0; i < ncomp; i++) + { + int b = cv::theRNG().uniform(0, 255); + int g = cv::theRNG().uniform(0, 255); + int r = cv::theRNG().uniform(0, 255); + + colors.push_back(cv::Vec3b((uchar)b, (uchar)g, (uchar)r)); + } + + // Create the result image + cv::Mat dst = cv::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 <= ncomp) + dst.at<cv::Vec3b>(i,j) = colors[index-1]; + else + dst.at<cv::Vec3b>(i,j) = cv::Vec3b(0,0,0); + } + } + + cv::imshow("dst", dst); + + cv::waitKey(0); + return 0; +} + |