Fixed #1996

modules/features2d/src/orb.cpp

@@ -778,36 +778,35 @@ void ORB::operator()( InputArray _image, InputArray _mask, vector<KeyPoint>& _ke
         {
             if( level < firstLevel )
             {
-                resize(image, imagePyramid[level], sz, scale, scale, INTER_LINEAR);
+                resize(image, imagePyramid[level], sz, 0, 0, INTER_LINEAR);
                 if (!mask.empty())
-                    resize(mask, maskPyramid[level], sz, scale, scale, INTER_LINEAR);
-                copyMakeBorder(imagePyramid[level], temp, border, border, border, border,
-                               BORDER_REFLECT_101+BORDER_ISOLATED);
+                    resize(mask, maskPyramid[level], sz, 0, 0, INTER_LINEAR);
             }
             else
             {
-                resize(imagePyramid[level-1], imagePyramid[level], sz,
-                       1./scaleFactor, 1./scaleFactor, INTER_LINEAR);
+                resize(imagePyramid[level-1], imagePyramid[level], sz, 0, 0, INTER_LINEAR);
                 if (!mask.empty())
-                    resize(maskPyramid[level-1], maskPyramid[level], sz,
-                           1./scaleFactor, 1./scaleFactor, INTER_LINEAR);
+                {
+                    resize(maskPyramid[level-1], maskPyramid[level], sz, 0, 0, INTER_LINEAR);
+                    threshold(maskPyramid[level], maskPyramid[level], 254, 0, THRESH_TOZERO);
+                }
+            }
+
             copyMakeBorder(imagePyramid[level], temp, border, border, border, border,
                            BORDER_REFLECT_101+BORDER_ISOLATED);
-            }
+            if (!mask.empty())
+                copyMakeBorder(maskPyramid[level], masktemp, border, border, border, border,
+                               BORDER_CONSTANT+BORDER_ISOLATED);
         }
         else
         {
             copyMakeBorder(image, temp, border, border, border, border,
                            BORDER_REFLECT_101);
-            image.copyTo(imagePyramid[level]);
             if( !mask.empty() )
-                mask.copyTo(maskPyramid[level]);
-        }
-        
-        if( !mask.empty() )
-            copyMakeBorder(maskPyramid[level], masktemp, border, border, border, border,
+                copyMakeBorder(mask, masktemp, border, border, border, border,
                                BORDER_CONSTANT+BORDER_ISOLATED);
         }
+    }
 
     // Pre-compute the keypoints (we keep the best over all scales, so this has to be done beforehand
     vector < vector<KeyPoint> > allKeypoints;

modules/features2d/test/test_features2d.cpp

@@ -1091,3 +1091,51 @@ TEST( Features2d_DescriptorMatcher_FlannBased, regression )
     CV_DescriptorMatcherTest test( "descriptor-matcher-flann-based", new FlannBasedMatcher, 0.04f );
     test.safe_run();
 }
+
+
+TEST(Features2D_ORB, _1996)
+{
+    cv::Ptr<cv::FeatureDetector> fd = cv::FeatureDetector::create("ORB");
+    cv::Ptr<cv::DescriptorExtractor> de = cv::DescriptorExtractor::create("ORB");
+
+    Mat image = cv::imread(string(cvtest::TS::ptr()->get_data_path()) + "shared/lena.jpg");
+    ASSERT_FALSE(image.empty());
+
+    Mat roi(image.size(), CV_8UC1, Scalar(0));
+
+    Point poly[] = {Point(100, 20), Point(300, 50), Point(400, 200), Point(10, 500)};
+    fillConvexPoly(roi, poly, int(sizeof(poly) / sizeof(poly[0])), Scalar(255));
+
+    std::vector<cv::KeyPoint> keypoints;
+    fd->detect(image, keypoints, roi);
+    cv::Mat descriptors;
+    de->compute(image, keypoints, descriptors);
+
+    //image.setTo(Scalar(255,255,255), roi);
+
+    int roiViolations = 0;
+    for(std::vector<cv::KeyPoint>::const_iterator kp = keypoints.begin(); kp != keypoints.end(); ++kp)
+    {
+        int x = cvRound(kp->pt.x);
+        int y = cvRound(kp->pt.y);
+
+        ASSERT_LE(0, x);
+        ASSERT_LE(0, y);
+        ASSERT_GT(image.cols, x);
+        ASSERT_GT(image.rows, y);
+
+        // if (!roi.at<uchar>(y,x))
+        // {
+        //     roiViolations++;
+        //     circle(image, kp->pt, 3, Scalar(0,0,255));
+        // }
+    }
+
+    // if(roiViolations)
+    // {
+    //     imshow("img", image);
+    //     waitKey();
+    // }
+
+    ASSERT_EQ(0, roiViolations);
+}
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