Table 1. Performance comparison and statistical analysis of different sizes of the dictionary and features percentages of the image on the Corel-1000 image collection (bold values indicate best performance).

Features % per image	Performance analysis in terms of the MAP performance (in %) on the different sizes of the dictionary
	20	50	100	200	400	600	800	1000	1200
10%	74.06	75.60	79.53	79.86	80.76	80.76	80.86	80.85	80.53
25%	76.46	78.33	81.16	80.93	81.16	80.99	81.26	81.19	81.25
50%	73.93	78.19	80.60	81.19	81.93	82.30	86.00	80.66	81.13
75%	74.40	77.93	80.40	82.05	81.73	82.05	82.06	81.00	81.33
100%	75.60	76.80	80.26	82.40	80.73	82.20	82.40	81.13	81.53
MAP	74.89	77.37	80.39	81.28	81.26	81.66	82.51	80.96	81.15
Std. dev.	1.097	1.158	0.590	0.999	0.550	0.726	2.042	0.215	0.377
Confidence interval	73.52- 76.25	75.93- 78.80	79.65- 81.12	80.04- 82.52	80.57- 81.94	80.75- 82.56	80.80- 83.10	80.69- 81.23	80.68- 81.62
Std. error	0.490	0.517	0.263	0.446	0.246	0.324	0.413	0.096	0.169
Non-parametric statistical analysis using Wilcoxon matched-pairs signed-rank test
Z-value	2.023	2.023	2.023	2.023	2.023	2.023	2.023	2.023	2.023
P-value	0.043	0.043	0.043	0.043	0.043	0.043	0.043	0.043	0.043