From d7e839b8c5b24e2d8eb62fd74e5a7e6371c2c483 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.a.alekhin@gmail.com>
Date: Sat, 21 Mar 2020 00:51:34 +0000
Subject: [PATCH] objdetect(QR): avoid bug with empty input

---
 modules/objdetect/src/qrcode.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/modules/objdetect/src/qrcode.cpp b/modules/objdetect/src/qrcode.cpp
index 4990dfd388..12d89919f9 100644
--- a/modules/objdetect/src/qrcode.cpp
+++ b/modules/objdetect/src/qrcode.cpp
@@ -122,9 +122,16 @@ void QRDetect::init(const Mat& src, double eps_vertical_, double eps_horizontal_
 
     eps_vertical   = eps_vertical_;
     eps_horizontal = eps_horizontal_;
-    adaptiveThreshold(barcode, bin_barcode, 255, ADAPTIVE_THRESH_GAUSSIAN_C, THRESH_BINARY, 83, 2);
-    adaptiveThreshold(resized_barcode, resized_bin_barcode, 255, ADAPTIVE_THRESH_GAUSSIAN_C, THRESH_BINARY, 83, 2);
 
+    if (!barcode.empty())
+        adaptiveThreshold(barcode, bin_barcode, 255, ADAPTIVE_THRESH_GAUSSIAN_C, THRESH_BINARY, 83, 2);
+    else
+        bin_barcode.release();
+
+    if (!resized_barcode.empty())
+        adaptiveThreshold(resized_barcode, resized_bin_barcode, 255, ADAPTIVE_THRESH_GAUSSIAN_C, THRESH_BINARY, 83, 2);
+    else
+        resized_bin_barcode.release();
 }
 
 vector<Vec3d> QRDetect::searchHorizontalLines()