--- opencv/modules/flann/include/opencv2/flann/any.h	(revision 6809)
+++ opencv/modules/flann/include/opencv2/flann/any.h	(revision 6881)
@@ -31,4 +31,10 @@
 };
 
+inline std::ostream& operator <<(std::ostream& out, const empty_any&)
+{
+    out << "[empty_any]";
+    return out;
+}
+
 struct base_any_policy
 {
--- opencv/modules/flann/include/opencv2/flann/lsh_index.h	(revision 6724)
+++ opencv/modules/flann/include/opencv2/flann/lsh_index.h	(revision 6881)
@@ -57,5 +57,5 @@
 struct LshIndexParams : public IndexParams
 {
-    LshIndexParams(unsigned int table_number, unsigned int key_size, unsigned int multi_probe_level)
+    LshIndexParams(unsigned int table_number = 12, unsigned int key_size = 20, unsigned int multi_probe_level = 2)
     {
         (* this)["algorithm"] = FLANN_INDEX_LSH;