Three-dimensional image reconstruction in capsule endoscopy

Figure 1 Various sensors which are commercially available[12]. A: Miniature magnetometers offer orientation and acceleration information, [Bertda Services (SEA) Pte. Ltd.]; B: Three-dimensional (3-D) range camera used in a widely commercial product; C: 3-D guidance system used in endoscopy devices (inition).

Figure 2 The Shape from Shading flow[12,13]. Capturing a surface using a camera removes depth information. Shape from Shading techniques try to reproduce the missing depth information from a given image.

Figure 3 Original capsule endoscopy and 3-D represented image depicting a protrusion. A: Original capsule endoscopy image depicting a protrusion (polyp); B: Its 3-D represented image processed by the proposed Shape from Shading approach.

Figure 4 Two-dimensional capsule endoscopy images (upper panel) and three-dimensional representation of above structures is seen (lower panel). A1, A2: P2 angioectasia; B1, B2: P1 angiectasia; C1, C2: Lymphoid hyperplasia with superficial ulceration; D1, D2: Aphthous ulcers; E1, E2: Serpiginous ulcers; F1, F2: Nodular lymphangiectasia; G1, G2: Another capsule endoscope still inside the small-bowel.

Figure 5 3-D representation of a single video capsule image with highlights removal (arrows).