Noise Resilient Local Gradient Orientation for Content-Based Image Retrieval

Table 4

Average retrieval precision and average retrieval recall of NRLGO at varying values of gradient orientation and color quantization levels by keeping local contrast information fixed at 5 on Corel 5k in RGB.

Color quantization level	Texture classification (Corel 5k, contrast information = 5)
	Precision (%)						Recall (%)
	6	12	18	24	30	36	6	12	18	24	30	36
128	60.1	60.5	59.9	59.5	59.8	59.7	7.07	7.10	7.11	7.06	7.13	7.09
64	58.5	57.4	57.8	55.2	56.9	58.5	6.80	6.69	6.83	6.81	6.81	6.85
32	53.5	50.2	55.0	55.6	54.7	49.4	6.20	6.23	6.31	6.30	6.27	6.25
16	44.4	48.7	46.6	47.4	47.6	48.5	5.30	5.39	5.47	5.50	5.55	5.57