From 94e0ac7d9f9e97d59572acc4e4b46750006785ad Mon Sep 17 00:00:00 2001
From: Aitik Gupta <aitikgupta@gmail.com>
Date: Tue, 29 Sep 2020 01:04:01 +0530
Subject: [PATCH] need atleast 4 corresponding points to calculate homography

---
 modules/calib3d/src/fundam.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/modules/calib3d/src/fundam.cpp b/modules/calib3d/src/fundam.cpp
index ebfd3af992..3c1b0ce00d 100644
--- a/modules/calib3d/src/fundam.cpp
+++ b/modules/calib3d/src/fundam.cpp
@@ -374,6 +374,9 @@ cv::Mat cv::findHomography( InputArray _points1, InputArray _points2,
                 return Mat();
             convertPointsFromHomogeneous(p, p);
         }
+        // Need at least 4 point correspondences to calculate Homography
+        if( npoints < 4 )
+            CV_Error(Error::StsVecLengthErr , "The input arrays should have at least 4 corresponding point sets to calculate Homography");
         p.reshape(2, npoints).convertTo(m, CV_32F);
     }