fixed bug in opencv_stitching (added handling of homography evaluation failure)

modules/stitching/main.cpp

@@ -549,6 +549,7 @@ int main(int argc, char* argv[])
                     sz.width = cvRound(full_img_sizes[i].width * compose_scale);
                     sz.height = cvRound(full_img_sizes[i].height * compose_scale);
                 }
+
                 Rect roi = warper->warpRoi(sz, static_cast<float>(cameras[i].focal), cameras[i].R);
                 corners[i] = roi.tl();
                 sizes[i] = roi.size();

modules/stitching/matchers.cpp

@@ -465,6 +465,8 @@ void BestOf2NearestMatcher::match(const ImageFeatures &features1, const ImageFea
 
     // Find pair-wise motion
     matches_info.H = findHomography(src_points, dst_points, matches_info.inliers_mask, CV_RANSAC);
+    if (abs(determinant(matches_info.H)) < numeric_limits<double>::epsilon())
+        return;
 
     // Find number of inliers
     matches_info.num_inliers = 0;