From 362655b02a028bb1780bf791f02ae4e523d0054c Mon Sep 17 00:00:00 2001
From: Vladislav Vinogradov <vlad.vinogradov@itseez.com>
Date: Thu, 29 Nov 2012 11:17:04 +0400
Subject: [PATCH] fixed Bug #2581

GoodFeaturesToTrackDetector_GPU fails when no corners found
---
 modules/gpu/src/gftt.cpp        |  6 ++++++
 modules/gpu/test/test_video.cpp | 15 +++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/modules/gpu/src/gftt.cpp b/modules/gpu/src/gftt.cpp
index ad24debcd..0c8f165ae 100644
--- a/modules/gpu/src/gftt.cpp
+++ b/modules/gpu/src/gftt.cpp
@@ -85,6 +85,12 @@ void cv::gpu::GoodFeaturesToTrackDetector_GPU::operator ()(const GpuMat& image,
 
     int total = findCorners_gpu(eig_, static_cast<float>(maxVal * qualityLevel), mask, tmpCorners_.ptr<float2>(), tmpCorners_.cols);
 
+    if (total == 0)
+    {
+        corners.release();
+        return;
+    }
+
     sortCorners_gpu(eig_, tmpCorners_.ptr<float2>(), total);
 
     if (minDistance < 1)
diff --git a/modules/gpu/test/test_video.cpp b/modules/gpu/test/test_video.cpp
index ca9442d69..ecba4b5a0 100644
--- a/modules/gpu/test/test_video.cpp
+++ b/modules/gpu/test/test_video.cpp
@@ -203,6 +203,21 @@ TEST_P(GoodFeaturesToTrack, Accuracy)
     }
 }
 
+TEST_P(GoodFeaturesToTrack, EmptyCorners)
+{
+    int maxCorners = 1000;
+    double qualityLevel = 0.01;
+
+    cv::gpu::GoodFeaturesToTrackDetector_GPU detector(maxCorners, qualityLevel, minDistance);
+
+    cv::gpu::GpuMat src(100, 100, CV_8UC1, cv::Scalar::all(0));
+    cv::gpu::GpuMat corners(1, maxCorners, CV_32FC2);
+
+    detector(src, corners);
+
+    ASSERT_TRUE( corners.empty() );
+}
+
 INSTANTIATE_TEST_CASE_P(GPU_Video, GoodFeaturesToTrack, testing::Combine(
     ALL_DEVICES,
     testing::Values(MinDistance(0.0), MinDistance(3.0))));