“Scanning from Heating” and “Shape from Fluorescence”: Two Non-Conventional Imaging Systems for 3D Digitization of Transparent Objects

Background

In this chapter, we present a new technique for 3D range scanning of transparent objects. 3D range scanning has been investigated for several decades and most of the proposed approaches assume a diffuse reflectance of the object’s surface. The broad literature on the subject is usually divided into active and passive techniques. Active light techniques, whose recent review is proposed by Blais (2004), include laser range scanning, coded structured light systems (Salvi, 2004) and time-of-flight scanners (Bokhabrine 2010) whereas passive techniques are mainly stereovision (Horn, 1986), “shape from optical flow”, shape from shading….or multiview acquisition system (Harvent, 2010).

The further a surface deviates from the Lambertian reflectance assumption, the less accurate standard 3D range scanning techniques become. Figure 1 is an example of a glass bottle scanned by a commercial scanner without any preparation of the sample surface (powder spray) prior digitization.

Figure 1.

(a) glass bottle; and (b) the 3D rendering obtained with a Vi 910 Minolta scanner without prior preparation of the surface

Coating the object with a powder prior digitization might solve the problem (see Figure 2), on the other hand, this cannot be done in many applications because it involves additional handlings of the objects (coating, cleaning) which include higher processing costs.

Figure 2.

From left to right: (a) specular object, same object after being coated with a powder; (b) transparent object