Fast Exact Nearest Neighbour Matching in High Dimensions Using 𝑑-D Sort

Table 1

1 NN query performance using a 128000-point dataset. Each column shows results for query descriptors extracted from an image related to the data in a different way. Results are presented as the ratio between linear search time and the given method's search time.

Method	Not in database	Rotated copy	Exact copy
ANN 𝑏-D tree	0.297	0.292	0.2872
ANN 𝑘-D tree	0.503	0.498	0.4909
FLANN	1.450	2.483	23.13
Linear	1.000	1.000	1.000
Linear partial	1.392	2.124	12.62
Linear ordered partial	2.588	4.397	12.62
𝑑-D sort	3.404	7.032	2246.0