Table 3. Class-wise comparison of precision for top 20 retrievals.

Class and Method	Visual words integration SIFT-SURF	Weighted average (0.7-0.3) SIFT-SURF	Color SIFT- EODH [37]	Spatial BoF [53]	SIFT-LBP [20]	HOG-LBP [20]
Africa	60.08 ± 1.94	52.68 ± 0.82	74.6	64	57	55
Beach	60.39 ± 1.39	56.32 ± 1.70	37.8	54	58	47
Buildings	69.66 ± 3.74	69.03 ± 1.54	53.9	53	43	56
Buses	93.65 ± 0.84	86.35 ± 1.52	96.7	94	93	91
Dinosaurs	99.88 ± 0.054	99.68 ± 0.16	99	98	98	94
Elephants	70.76 ± 1.90	67.55 ± 1.58	65.9	78	58	49
Flowers	88.37 ± 0.76	85.99 ± 0.67	91.2	71	83	85
Horses	82.77 ± 0.70	76.37 ± 0.97	86.9	93	68	52
Mountains	61.08 ± 0.71	58.85 ± 1.03	58.5	42	46	37
Food	65.09 ± 1.76	53.00 ± 1.59	62.2	50	53	55
Mean	75.17	70.58	72.67	69.7	65.7	62.1