diff --git a/modules/flann/include/opencv2/flann/all_indices.h b/modules/flann/include/opencv2/flann/all_indices.h
index 865ca53ae..898ac0998 100644
--- a/modules/flann/include/opencv2/flann/all_indices.h
+++ b/modules/flann/include/opencv2/flann/all_indices.h
@@ -49,19 +49,19 @@ NNIndex<T>* create_index_by_type(const Matrix<T>& dataset, const IndexParams& pa
 
 	NNIndex<T>* nnIndex;
 	switch (index_type) {
-	case LINEAR:
+	case FLANN_INDEX_LINEAR:
 		nnIndex = new LinearIndex<T>(dataset, (const LinearIndexParams&)params);
 		break;
-	case KDTREE:
+	case FLANN_INDEX_KDTREE:
 		nnIndex = new KDTreeIndex<T>(dataset, (const KDTreeIndexParams&)params);
 		break;
-	case KMEANS:
+	case FLANN_INDEX_KMEANS:
 		nnIndex = new KMeansIndex<T>(dataset, (const KMeansIndexParams&)params);
 		break;
-	case COMPOSITE:
+	case FLANN_INDEX_COMPOSITE:
 		nnIndex = new CompositeIndex<T>(dataset, (const CompositeIndexParams&) params);
 		break;
-	case AUTOTUNED:
+	case FLANN_INDEX_AUTOTUNED:
 		nnIndex = new AutotunedIndex<T>(dataset, (const AutotunedIndexParams&) params);
 		break;
 	default:
diff --git a/modules/flann/include/opencv2/flann/autotuned_index.h b/modules/flann/include/opencv2/flann/autotuned_index.h
index 597a080ba..7a6b280fb 100644
--- a/modules/flann/include/opencv2/flann/autotuned_index.h
+++ b/modules/flann/include/opencv2/flann/autotuned_index.h
@@ -44,7 +44,7 @@ namespace cvflann
 struct AutotunedIndexParams : public IndexParams {
 	AutotunedIndexParams( float target_precision_ = 0.8, float build_weight_ = 0.01,
 			float memory_weight_ = 0, float sample_fraction_ = 0.1) :
-		IndexParams(AUTOTUNED),
+		IndexParams(FLANN_INDEX_AUTOTUNED),
 		target_precision(target_precision_),
 		build_weight(build_weight_),
 		memory_weight(memory_weight_),
@@ -55,8 +55,6 @@ struct AutotunedIndexParams : public IndexParams {
 	float memory_weight;       // index memory weighting factor
     float sample_fraction;     // what fraction of the dataset to use for autotuning
 
-	flann_algorithm_t getIndexType() const { return algorithm; }
-
 	void print() const
 	{
 		logger().info("Index type: %d\n",(int)algorithm);
@@ -123,13 +121,13 @@ public:
 		logger().info("----------------------------------------------------\n");
     	flann_algorithm_t index_type = bestParams->getIndexType();
     	switch (index_type) {
-    	case LINEAR:
+    	case FLANN_INDEX_LINEAR:
     		bestIndex = new LinearIndex<ELEM_TYPE>(dataset, (const LinearIndexParams&)*bestParams);
     		break;
-    	case KDTREE:
+    	case FLANN_INDEX_KDTREE:
     		bestIndex = new KDTreeIndex<ELEM_TYPE>(dataset, (const KDTreeIndexParams&)*bestParams);
     		break;
-    	case KMEANS:
+    	case FLANN_INDEX_KMEANS:
     		bestIndex = new KMeansIndex<ELEM_TYPE>(dataset, (const KMeansIndexParams&)*bestParams);
     		break;
     	default:
@@ -211,7 +209,7 @@ public:
     */
     virtual flann_algorithm_t getType() const
     {
-    	return AUTOTUNED;
+    	return FLANN_INDEX_AUTOTUNED;
     }
 
 private:
@@ -347,7 +345,7 @@ private:
         for (size_t i=0; i<ARRAY_LEN(maxIterations); ++i) {
             for (size_t j=0; j<ARRAY_LEN(branchingFactors); ++j) {
 
-            	kmeansCosts[cnt].second.centers_init = CENTERS_RANDOM;
+            	kmeansCosts[cnt].second.centers_init = FLANN_CENTERS_RANDOM;
             	kmeansCosts[cnt].second.iterations = maxIterations[i];
             	kmeansCosts[cnt].second.branching = branchingFactors[j];
 
@@ -569,7 +567,7 @@ private:
 
             float searchTime;
             float cb_index;
-            if (bestIndex->getType() == KMEANS) {
+            if (bestIndex->getType() == FLANN_INDEX_KMEANS) {
                 logger().info("KMeans algorithm, estimating cluster border factor\n");
                 KMeansIndex<ELEM_TYPE>* kmeans = (KMeansIndex<ELEM_TYPE>*)bestIndex;
                 float bestSearchTime = -1;
diff --git a/modules/flann/include/opencv2/flann/composite_index.h b/modules/flann/include/opencv2/flann/composite_index.h
index dfcfab515..4d2bfce81 100644
--- a/modules/flann/include/opencv2/flann/composite_index.h
+++ b/modules/flann/include/opencv2/flann/composite_index.h
@@ -40,8 +40,8 @@ namespace cvflann
 
 struct CompositeIndexParams : public IndexParams {
 	CompositeIndexParams(int trees_ = 4, int branching_ = 32, int iterations_ = 11,
-			flann_centers_init_t centers_init_ = CENTERS_RANDOM, float cb_index_ = 0.2 ) :
-		IndexParams(COMPOSITE),
+			flann_centers_init_t centers_init_ = FLANN_CENTERS_RANDOM, float cb_index_ = 0.2 ) :
+		IndexParams(FLANN_INDEX_COMPOSITE),
 		trees(trees_),
 		branching(branching_),
 		iterations(iterations_),
@@ -54,8 +54,6 @@ struct CompositeIndexParams : public IndexParams {
 	flann_centers_init_t centers_init;          // algorithm used for picking the initial cluster centers for kmeans tree
     float cb_index;            // cluster boundary index. Used when searching the kmeans tree
 
-	flann_algorithm_t getIndexType() const { return algorithm; }
-
 	void print() const
 	{
 		logger().info("Index type: %d\n",(int)algorithm);
@@ -102,7 +100,7 @@ public:
 
     flann_algorithm_t getType() const
     {
-        return COMPOSITE;
+        return FLANN_INDEX_COMPOSITE;
     }
 
 
diff --git a/modules/flann/include/opencv2/flann/dist.h b/modules/flann/include/opencv2/flann/dist.h
index b10a01a7b..2ddbee31e 100644
--- a/modules/flann/include/opencv2/flann/dist.h
+++ b/modules/flann/include/opencv2/flann/dist.h
@@ -304,21 +304,21 @@ template <typename Iterator1, typename Iterator2>
 double custom_dist(Iterator1 first1, Iterator1 last1, Iterator2 first2, double acc = 0)
 {
 	switch (flann_distance_type()) {
-	case EUCLIDEAN:
+	case FLANN_DIST_EUCLIDEAN:
 		return euclidean_dist(first1, last1, first2, acc);
-	case MANHATTAN:
+	case FLANN_DIST_MANHATTAN:
 		return manhattan_dist(first1, last1, first2, acc);
-	case MINKOWSKI:
+	case FLANN_DIST_MINKOWSKI:
 		return minkowski_dist(first1, last1, first2, acc);
-	case MAX_DIST:
+	case FLANN_DIST_MAX:
 		return max_dist(first1, last1, first2, acc);
-	case HIK:
+	case FLANN_DIST_HIST_INTERSECT:
 		return hist_intersection_dist_sq(first1, last1, first2, acc);
-	case HELLINGER:
+	case FLANN_DIST_HELLINGER:
 		return hellinger_dist(first1, last1, first2, acc);
-	case CS:
+	case FLANN_DIST_CS:
 		return chi_square_dist(first1, last1, first2, acc);
-	case KL:
+	case FLANN_DIST_KL:
 		return kl_divergence(first1, last1, first2, acc);
 	default:
 		return euclidean_dist(first1, last1, first2, acc);
diff --git a/modules/flann/include/opencv2/flann/flann_base.hpp b/modules/flann/include/opencv2/flann/flann_base.hpp
index 227f94501..46143df26 100644
--- a/modules/flann/include/opencv2/flann/flann_base.hpp
+++ b/modules/flann/include/opencv2/flann/flann_base.hpp
@@ -67,12 +67,10 @@ CV_EXPORTS void set_distance_type(flann_distance_t distance_type, int order);
 
 
 struct CV_EXPORTS SavedIndexParams : public IndexParams {
-	SavedIndexParams(std::string filename_) : IndexParams(SAVED), filename(filename_) {}
+	SavedIndexParams(std::string filename_) : IndexParams(FLANN_INDEX_SAVED), filename(filename_) {}
 
 	std::string filename;		// filename of the stored index
 
-	flann_algorithm_t getIndexType() const { return algorithm; }
-
 	void print() const
 	{
 		logger().info("Index type: %d\n",(int)algorithm);
@@ -138,7 +136,7 @@ Index<T>::Index(const Matrix<T>& dataset, const IndexParams& params)
 	flann_algorithm_t index_type = params.getIndexType();
     built = false;
 
-	if (index_type==SAVED) {
+	if (index_type==FLANN_INDEX_SAVED) {
 		nnIndex = load_saved_index(dataset, ((const SavedIndexParams&)params).filename);
         built = true;
 	}
diff --git a/modules/flann/include/opencv2/flann/general.h b/modules/flann/include/opencv2/flann/general.h
index be879a9ff..7ca25cd9a 100644
--- a/modules/flann/include/opencv2/flann/general.h
+++ b/modules/flann/include/opencv2/flann/general.h
@@ -44,18 +44,18 @@ namespace cvflann {
 
 /* Nearest neighbour index algorithms */
 enum flann_algorithm_t {
-	LINEAR = 0,
-	KDTREE = 1,
-	KMEANS = 2,
-	COMPOSITE = 3,
-	SAVED = 254,
-	AUTOTUNED = 255
+	FLANN_INDEX_LINEAR = 0,
+	FLANN_INDEX_KDTREE = 1,
+	FLANN_INDEX_KMEANS = 2,
+	FLANN_INDEX_COMPOSITE = 3,
+	FLANN_INDEX_SAVED = 254,
+	FLANN_INDEX_AUTOTUNED = 255
 };
 
 enum flann_centers_init_t {
-	CENTERS_RANDOM = 0,
-	CENTERS_GONZALES = 1,
-	CENTERS_KMEANSPP = 2
+	FLANN_CENTERS_RANDOM = 0,
+	FLANN_CENTERS_GONZALES = 1,
+	FLANN_CENTERS_KMEANSPP = 2
 };
 
 enum flann_log_level_t {
@@ -67,29 +67,31 @@ enum flann_log_level_t {
 };
 
 enum flann_distance_t {
-	EUCLIDEAN = 1,
-	MANHATTAN = 2,
-	MINKOWSKI = 3,
-	MAX_DIST   = 4,
-	HIK       = 5,
-	HELLINGER = 6,
-	CS        = 7,
-	CHI_SQUARE = 7,
-	KL        = 8,
-	KULLBACK_LEIBLER        = 8
+	FLANN_DIST_EUCLIDEAN = 1,
+	FLANN_DIST_L2 = 1,
+	FLANN_DIST_MANHATTAN = 2,
+	FLANN_DIST_L1 = 2,
+	FLANN_DIST_MINKOWSKI = 3,
+	FLANN_DIST_MAX       = 4,
+	FLANN_DIST_HIST_INTERSECT = 5,
+	FLANN_DIST_HELLINGER = 6,
+	FLANN_DIST_CHI_SQUARE = 7,
+	FLANN_DIST_CS         = 7,
+	FLANN_DIST_KULLBACK_LEIBLER        = 8,
+	FLANN_DIST_KL        = 8
 };
 
 enum flann_datatype_t {
-	INT8 = 0,
-	INT16 = 1,
-	INT32 = 2,
-	INT64 = 3,
-	UINT8 = 4,
-	UINT16 = 5,
-	UINT32 = 6,
-	UINT64 = 7,
-	FLOAT32 = 8,
-	FLOAT64 = 9
+	FLANN_INT8 = 0,
+	FLANN_INT16 = 1,
+	FLANN_INT32 = 2,
+	FLANN_INT64 = 3,
+	FLANN_UINT8 = 4,
+	FLANN_UINT16 = 5,
+	FLANN_UINT32 = 6,
+	FLANN_UINT64 = 7,
+	FLANN_FLOAT32 = 8,
+	FLANN_FLOAT64 = 9
 };
 
 template <typename ELEM_TYPE>
@@ -125,7 +127,7 @@ protected:
 	
 public:
 	virtual ~IndexParams() {}
-	virtual flann_algorithm_t getIndexType() const = 0;
+	virtual flann_algorithm_t getIndexType() const { return algorithm; }
 
 	virtual void print() const = 0;
 
diff --git a/modules/flann/include/opencv2/flann/kdtree_index.h b/modules/flann/include/opencv2/flann/kdtree_index.h
index bf485d33f..ffcbb4625 100644
--- a/modules/flann/include/opencv2/flann/kdtree_index.h
+++ b/modules/flann/include/opencv2/flann/kdtree_index.h
@@ -50,12 +50,10 @@ namespace cvflann
 {
 
 struct CV_EXPORTS KDTreeIndexParams : public IndexParams {
-	KDTreeIndexParams(int trees_ = 4) : IndexParams(KDTREE), trees(trees_) {};
+	KDTreeIndexParams(int trees_ = 4) : IndexParams(FLANN_INDEX_KDTREE), trees(trees_) {};
 
 	int trees;                 // number of randomized trees to use (for kdtree)
 
-	flann_algorithm_t getIndexType() const { return algorithm; }
-
 	void print() const
 	{
 		logger().info("Index type: %d\n",(int)algorithm);
@@ -167,7 +165,7 @@ public:
 
     flann_algorithm_t getType() const
     {
-        return KDTREE;
+        return FLANN_INDEX_KDTREE;
     }
 
 	/**
diff --git a/modules/flann/include/opencv2/flann/kmeans_index.h b/modules/flann/include/opencv2/flann/kmeans_index.h
index a0a1d6626..6c688d808 100644
--- a/modules/flann/include/opencv2/flann/kmeans_index.h
+++ b/modules/flann/include/opencv2/flann/kmeans_index.h
@@ -52,8 +52,8 @@ namespace cvflann
 
 struct CV_EXPORTS KMeansIndexParams : public IndexParams {
 	KMeansIndexParams(int branching_ = 32, int iterations_ = 11,
-			flann_centers_init_t centers_init_ = CENTERS_RANDOM, float cb_index_ = 0.2 ) :
-		IndexParams(KMEANS),
+			flann_centers_init_t centers_init_ = FLANN_CENTERS_RANDOM, float cb_index_ = 0.2 ) :
+		IndexParams(FLANN_INDEX_KMEANS),
 		branching(branching_),
 		iterations(iterations_),
 		centers_init(centers_init_),
@@ -64,8 +64,6 @@ struct CV_EXPORTS KMeansIndexParams : public IndexParams {
 	flann_centers_init_t centers_init;          // algorithm used for picking the initial cluster centers for kmeans tree
     float cb_index;            // cluster boundary index. Used when searching the kmeans tree
 
-	flann_algorithm_t getIndexType() const { return KMEANS; }
-
 	void print() const
 	{
 		logger().info("Index type: %d\n",(int)algorithm);
@@ -379,7 +377,7 @@ public:
 
     flann_algorithm_t getType() const
     {
-        return KMEANS;
+        return FLANN_INDEX_KMEANS;
     }
 
 	/**
@@ -404,13 +402,13 @@ public:
         }
         flann_centers_init_t centersInit = params.centers_init;
 
-        if (centersInit==CENTERS_RANDOM) {
+        if (centersInit==FLANN_CENTERS_RANDOM) {
         	chooseCenters = &KMeansIndex::chooseCentersRandom;
         }
-        else if (centersInit==CENTERS_GONZALES) {
+        else if (centersInit==FLANN_CENTERS_GONZALES) {
         	chooseCenters = &KMeansIndex::chooseCentersGonzales;
         }
-        else if (centersInit==CENTERS_KMEANSPP) {
+        else if (centersInit==FLANN_CENTERS_KMEANSPP) {
                 	chooseCenters = &KMeansIndex::chooseCentersKMeanspp;
         }
 		else {
diff --git a/modules/flann/include/opencv2/flann/linear_index.h b/modules/flann/include/opencv2/flann/linear_index.h
index de7c51c3f..c24cc0643 100644
--- a/modules/flann/include/opencv2/flann/linear_index.h
+++ b/modules/flann/include/opencv2/flann/linear_index.h
@@ -39,9 +39,7 @@ namespace cvflann
 {
 
 struct CV_EXPORTS LinearIndexParams : public IndexParams {
-	LinearIndexParams() : IndexParams(LINEAR) {};
-
-	flann_algorithm_t getIndexType() const { return algorithm; }
+	LinearIndexParams() : IndexParams(FLANN_INDEX_LINEAR) {};
 
 	void print() const
 	{
@@ -65,7 +63,7 @@ public:
 
     flann_algorithm_t getType() const
     {
-        return LINEAR;
+        return FLANN_INDEX_LINEAR;
     }
 
 
diff --git a/modules/flann/include/opencv2/flann/saving.h b/modules/flann/include/opencv2/flann/saving.h
index bc75eb509..52116ec96 100644
--- a/modules/flann/include/opencv2/flann/saving.h
+++ b/modules/flann/include/opencv2/flann/saving.h
@@ -37,14 +37,14 @@
 namespace cvflann
 {
 template <typename T> struct Datatype {};
-template<> struct Datatype<char> { static flann_datatype_t type() { return INT8; } };
-template<> struct Datatype<short> { static flann_datatype_t type() { return INT16; } };
-template<> struct Datatype<int> { static flann_datatype_t type() { return INT32; } };
-template<> struct Datatype<unsigned char> { static flann_datatype_t type() { return UINT8; } };
-template<> struct Datatype<unsigned short> { static flann_datatype_t type() { return UINT16; } };
-template<> struct Datatype<unsigned int> { static flann_datatype_t type() { return UINT32; } };
-template<> struct Datatype<float> { static flann_datatype_t type() { return FLOAT32; } };
-template<> struct Datatype<double> { static flann_datatype_t type() { return FLOAT64; } };
+template<> struct Datatype<char> { static flann_datatype_t type() { return FLANN_INT8; } };
+template<> struct Datatype<short> { static flann_datatype_t type() { return FLANN_INT16; } };
+template<> struct Datatype<int> { static flann_datatype_t type() { return FLANN_INT32; } };
+template<> struct Datatype<unsigned char> { static flann_datatype_t type() { return FLANN_UINT8; } };
+template<> struct Datatype<unsigned short> { static flann_datatype_t type() { return FLANN_UINT16; } };
+template<> struct Datatype<unsigned int> { static flann_datatype_t type() { return FLANN_UINT32; } };
+template<> struct Datatype<float> { static flann_datatype_t type() { return FLANN_FLOAT32; } };
+template<> struct Datatype<double> { static flann_datatype_t type() { return FLANN_FLOAT64; } };
 
 
 CV_EXPORTS const char* FLANN_SIGNATURE();
diff --git a/modules/flann/src/flann.cpp b/modules/flann/src/flann.cpp
index 3742381ef..30a82ea6f 100644
--- a/modules/flann/src/flann.cpp
+++ b/modules/flann/src/flann.cpp
@@ -35,7 +35,7 @@ namespace cvflann
 /** Global variable indicating the distance metric
  * to be used.
  */
-flann_distance_t flann_distance_type_ = EUCLIDEAN;
+flann_distance_t flann_distance_type_ = FLANN_DIST_EUCLIDEAN;
 flann_distance_t flann_distance_type() { return flann_distance_type_; }
 
 /**
@@ -208,12 +208,12 @@ class StaticInit
 public:
 	StaticInit()
 	{
-		ParamsFactory_instance().register_<LinearIndexParams>(LINEAR);
-		ParamsFactory_instance().register_<KDTreeIndexParams>(KDTREE);
-		ParamsFactory_instance().register_<KMeansIndexParams>(KMEANS);
-		ParamsFactory_instance().register_<CompositeIndexParams>(COMPOSITE);
-		ParamsFactory_instance().register_<AutotunedIndexParams>(AUTOTUNED);
-//		ParamsFactory::instance().register_<SavedIndexParams>(SAVED);
+		ParamsFactory_instance().register_<LinearIndexParams>(FLANN_INDEX_LINEAR);
+		ParamsFactory_instance().register_<KDTreeIndexParams>(FLANN_INDEX_KDTREE);
+		ParamsFactory_instance().register_<KMeansIndexParams>(FLANN_INDEX_KMEANS);
+		ParamsFactory_instance().register_<CompositeIndexParams>(FLANN_INDEX_COMPOSITE);
+		ParamsFactory_instance().register_<AutotunedIndexParams>(FLANN_INDEX_AUTOTUNED);
+//		ParamsFactory::instance().register_<SavedIndexParams>(FLANN_INDEX_SAVED);
 	}
 };
 StaticInit __init;