From 22cbfd671831cd6f1df3f0eff3641a3d8426a947 Mon Sep 17 00:00:00 2001
From: berak <px1704@web.de>
Date: Wed, 17 Mar 2021 09:08:40 +0100
Subject: [PATCH] ximgproc: add an assert in thinning()

---
 modules/ximgproc/src/thinning.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/modules/ximgproc/src/thinning.cpp b/modules/ximgproc/src/thinning.cpp
index c62c13e6d..b28784d28 100644
--- a/modules/ximgproc/src/thinning.cpp
+++ b/modules/ximgproc/src/thinning.cpp
@@ -69,6 +69,7 @@ static void thinningIteration(Mat img, int iter, int thinningType){
 // Apply the thinning procedure to a given image
 void thinning(InputArray input, OutputArray output, int thinningType){
     Mat processed = input.getMat().clone();
+    CV_CheckTypeEQ(processed.type(), CV_8UC1, "");
     // Enforce the range of the input image to be in between 0 - 255
     processed /= 255;