We present a new color (RGB) imaging 3D laser scanner prototype recently developed in ENEA (Italy). The sensor is
based on AM range finding technique and uses three distinct beams (650nm, 532nm and 450nm respectively) in
monostatic configuration. During a scan the laser beams are simultaneously swept over the target, yielding range and
three separated channels (R, G and B) of reflectance information for each sampled point. This information, organized in
range and reflectance images, is then elaborated to produce very high definition color pictures and faithful, natively
colored 3D models. Notable characteristics of the system are the absence of shadows in the acquired reflectance images -
due to the system's monostatic setup and intrinsic self-illumination capability - and high noise rejection, achieved by
using a narrow field of view and interferential filters. The system is also very accurate in range determination (accuracy
better than 10-4) at distances up to several meters. These unprecedented features make the system particularly suited to
applications in the domain of cultural heritage preservation, where it could be used by conservators for examining in
detail the status of degradation of frescoed walls, monuments and paintings, even at several meters of distance and in
hardly accessible locations.
After providing some theoretical background, we describe the general architecture and operation modes of the color 3D
laser scanner, by reporting and discussing first experimental results and comparing high-definition color images
produced by the instrument with photographs of the same subjects taken with a Nikon D70 digital camera.