diff --git a/modules/flann/doc/flann_fast_approximate_nearest_neighbor_search.rst b/modules/flann/doc/flann_fast_approximate_nearest_neighbor_search.rst index 771e897a0b..05ef45a9ce 100644 --- a/modules/flann/doc/flann_fast_approximate_nearest_neighbor_search.rst +++ b/modules/flann/doc/flann_fast_approximate_nearest_neighbor_search.rst @@ -85,8 +85,27 @@ The method constructs a fast search structure from a set of features using the s flann_centers_init_t centers_init = CENTERS_RANDOM, float cb_index = 0.2 ); }; - - .. + + * + **LshIndexParams** When using a parameters object of this type the index created uses multi-probe LSH (by ``Multi-Probe LSH: Efficient Indexing for High-Dimensional Similarity Search`` by Qin Lv, William Josephson, Zhe Wang, Moses Charikar, Kai Li., Proceedings of the 33rd International Conference on Very Large Data Bases (VLDB). Vienna, Austria. September 2007) :: + + struct LshIndexParams : public IndexParams + { + LshIndexParams( + unsigned int table_number, + unsigned int key_size, + unsigned int multi_probe_level ); + }; + + .. + + * **table_number** the number of hash tables to use (between 10 and 30 usually). + + + * **key_size** the size of the hash key in bits (between 10 and 20 usually). + + + * **multi_probe_level** the number of bits to shift to check for neighboring buckets (0 is regular LSH, 2 is recommended). * **AutotunedIndexParams** When passing an object of this type the index created is automatically tuned to offer the best performance, by choosing the optimal index type (randomized kd-trees, hierarchical kmeans, linear) and parameters for the dataset provided. ::