Identification of Contour Lines from Average-Quality Scanned Topographic Maps

Table 2

Evaluation results of different contour lines extraction methods.

Method	Image label	Completeness	Accuracy	Quality	RMS	Gaps	Misconnections
The proposed method	Figure 8(j)	0.911	0.924	0.854	0.110	28	0
	Figure 9(j)	0.907	0.905	0.837	0.112	24	0
	Figure 10(j)	0.856	0.873	0.768	0.118	192	0
Chen’s method	Figure 8(k)	0.920	0.893	0.841	0.112	57	0
	Figure 9(k)	0.878	0.828	0.759	0.120	44	2
	Figure 10(k)	0.837	0.807	0.708	0.127	219	4
Samet’s method	Figure 8(l)	0.908	0.912	0.846	0.111	58	0
	Figure 9(l)	0.894	0.881	0.791	0.116	46	0
	Figure 10(l)	0.829	0.815	0.714	0.125	242	6