Automatic Side-Scan Sonar Image Enhancement in Curvelet Transform Domain

Figure 12

Mapping curves of enhanced images. Key: green solid line, no-change mapping; cyan solid line, HE; red dash-dotted line, AIE-NSCT; blue solid line, PFBE; black dashed line, the proposed algorithm.

(a) Sand

(b) Plane

(c) River landform

(d) Bridge pier