Figure 2. Principal setup of the multispectral system.

An integrating sphere coated with a matte white coating ensures optimal lighting conditions. In the rim of the sphere a set of narrow band light emitting diodes ranging from 395 to 970 nm. are mounted. The image acquisition is performed by a monochrome grayscale CCD camera mounted in the top of the sphere. The arrows illustrate how the light is distributed inside the sphere to uniformly illuminate the fillet.