red green blue imaging topological radar

Authors: M. Guarneri, L. Bartolini, G. Fornetti, M. Ferri De Collibus, M. Francucci, E. Paglia, R. Ricci

Ente per le Nuove tecnologie, l'Energia e l'Ambiente

Co-Authors: J. Kolar, I. Nemec, M. Strlic

Massimiliano Guarneri – guarneri@frascati.enea.it

What will talk about

Introduction to RGB - Imaging Topological Radar Calibration methods and problems concerning

laser instability for long time-acquisitions Color measurement and color perception ITR Tools: software suite for collecting,

manipulating and inspecting RGB-ITR data Hrastovljie: first concrete result obtained by

RGB-ITR in monitoring and cataloguing fine arts Future developments Conclusions

Massimiliano Guarneri – guarneri@frascati.enea.it

RGB-ITR system

Optical head

Electronic system

Laptop

Massimiliano Guarneri – guarneri@frascati.enea.it

Introduction to RGB-ITR

Optical head

Scanning system

Electronic system

Dichroic filter

Dichroic filter

* Here lasers are divided only for clarifying that

we are investigating the scene with 3 different laser sources

*

Massimiliano Guarneri – guarneri@frascati.enea.it

Inside the optical head

Massimiliano Guarneri – guarneri@frascati.enea.it

Inside the optical head

Massimiliano Guarneri – guarneri@frascati.enea.it

Ferrula vs dichroic filter

Ferrula features

Three separated laser beams (6 mrad among the red beam)

No power loss outside ferrula

Three RGB layers has to be registered via software

Suitable in a range of 15-35m

Dichroic filter features

Three superimposed laser beams

Power loss outside dichroic filter (about 60%)

Three RGB layers automatically registered

Suitable in a range of 3-15m

Massimiliano Guarneri – guarneri@frascati.enea.it

Lasers source stability

Red

Massimiliano Guarneri – guarneri@frascati.enea.it

Lasers source stability

Green

Massimiliano Guarneri – guarneri@frascati.enea.it

Lasers source stability

Blue

Massimiliano Guarneri – guarneri@frascati.enea.it

Calibration methods

During scanning process the ITR system uses white calibrated target for registering RGB space with the same reference point.

After Hrastovlje we introduced a new calibration method so to eliminate laser sources instability: special calibrated target are acquired every one hour.

Massimiliano Guarneri – guarneri@frascati.enea.it

Color measurement and color perception

RGB-ITR

Color measurement

Calibrated laser sources

Discriminate lambertian and back reflected component

Color perception

Acquired data free from external

light sources

Software algorithms

Massimiliano Guarneri – guarneri@frascati.enea.it

ITR Tools

ITR Tools

itrScanSytem PLY VieweritrAnalyzer

2D software (Photoshop, Paint

Shop Pro, Gimp,…)

3D software (Rapidform, Maya, Blender, Rhino,…)

RGB-ITR data manipulation and

inspection

Massimiliano Guarneri – guarneri@frascati.enea.it

Results obtained in Hrastovlje

Cerkev sv Trojica’s historySmall XII sec. (and later) Romanic church, was fortified against Turkish advance. Vaults, apse and walls were painted by Janez iz Kastva at the end of XV sec.

Massimiliano Guarneri – guarneri@frascati.enea.it

Our purposes

Due to the Italy-Slovenia collaboration, a 3D color digitalization of the most significative parts of the church was made for:Monitoring church structureMonitoring church’s paintingsDemonstrating that RGB-ITR images can be used for cataloguing cultural heritage

Massimiliano Guarneri – guarneri@frascati.enea.it

RGB-ITR parameters set in the church

* Due to a compromise with the available time, we set a resolution 4 times bigger than the real ITR resolution.

Massimiliano Guarneri – guarneri@frascati.enea.it

Inspection Data – structure profile

Massimiliano Guarneri – guarneri@frascati.enea.it

Inspection Data – structure profile

Massimiliano Guarneri – guarneri@frascati.enea.it

Inspection Data – structure profile

Massimiliano Guarneri – guarneri@frascati.enea.it

Isohypse over 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Inspection data – metrology

Massimiliano Guarneri – guarneri@frascati.enea.it

Inspection Data – color profile

Massimiliano Guarneri – guarneri@frascati.enea.it

Inspection Data – color profile

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating inside 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating inside 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating inside 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating inside 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating inside 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Navigating inside 3D data

Massimiliano Guarneri – guarneri@frascati.enea.it

Mesh structure

Regular structure of the wireframe obtained by ITR data.

ITR mesh can be easily animated (i.e. structure stress simulation).

Mesh decimated of 90%

Massimiliano Guarneri – guarneri@frascati.enea.it

Mesh structure

Regular structure of the wireframe obtained by ITR data.

ITR mesh can be easily animated (i.e. structure stress simulation).

Morphological data are completely connected with color information – UV coords implicitly given.

Color information are not affected by external light sources.

Massimiliano Guarneri – guarneri@frascati.enea.it

Future developments

The next step will be the introduction of polariser for discriminating lambertian (which is color responsible) from back reflected component (which strongly depends on surface).

Strongest calibration method, so to avoid laser sources instabilities, will be introduced. Moreover a better white calibration at different distances will be permitted.

Massimiliano Guarneri – guarneri@frascati.enea.it

Conclusions

With the same technique introduced by ITR systems, an underwater 3D laser scanner is under investigation. Presently the developed prototype uses a monochromatic laser source and is able to acquire objects up to 3m with a resolution of 0.5 mm

Massimiliano Guarneri – guarneri@frascati.enea.it

Carafa Chapel (Rome) - Under construction

Massimiliano Guarneri – guarneri@frascati.enea.it

Carafa Chapel (Rome) - Under construction