vendor: OpenCV 5.0.0 snapshot at 755e50675d97db9b7d449d8bd6b09888646f6c6e

modules/ximgproc/samples/thinning.cpp

@@ -0,0 +1,45 @@
+#include <iostream>
+
+#include "opencv2/imgproc.hpp"
+#include "opencv2/highgui.hpp"
+
+#include "opencv2/ximgproc.hpp"
+
+using namespace std;
+using namespace cv;
+
+int main()
+{
+    Mat img = imread("opencv-logo.png", IMREAD_COLOR);
+    resize(img, img, Size(), 0.5, 0.5, INTER_LINEAR_EXACT);
+
+    /// Threshold the input image
+    Mat img_grayscale, img_binary;
+    cvtColor(img, img_grayscale,COLOR_BGR2GRAY);
+    threshold(img_grayscale, img_binary, 0, 255, THRESH_OTSU | THRESH_BINARY_INV);
+
+    /// Apply thinning to get a skeleton
+    Mat img_thinning_ZS, img_thinning_GH;
+    ximgproc::thinning(img_binary, img_thinning_ZS, ximgproc::THINNING_ZHANGSUEN);
+    ximgproc::thinning(img_binary, img_thinning_GH, ximgproc::THINNING_GUOHALL);
+
+    /// Make 3 channel images from thinning result
+    Mat result_ZS(img.rows, img.cols, CV_8UC3), result_GH(img.rows, img.cols, CV_8UC3);
+
+    Mat in[] = { img_thinning_ZS, img_thinning_ZS, img_thinning_ZS };
+    Mat in2[] = { img_thinning_GH, img_thinning_GH, img_thinning_GH };
+    int from_to[] = { 0,0, 1,1, 2,2 };
+    mixChannels( in, 3, &result_ZS, 1, from_to, 3 );
+    mixChannels( in2, 3, &result_GH, 1, from_to, 3 );
+
+    /// Combine everything into a canvas
+    Mat canvas(img.rows, img.cols * 3, CV_8UC3);
+    img.copyTo( canvas( Rect(0, 0, img.cols, img.rows) ) );
+    result_ZS.copyTo( canvas( Rect(img.cols, 0, img.cols, img.rows) ) );
+    result_GH.copyTo( canvas( Rect(img.cols*2, 0, img.cols, img.rows) ) );
+
+    /// Visualize result
+    imshow("Skeleton", canvas); waitKey(0);
+
+    return 0;
+}