What Is RTI?

Reflectance Transformation Imaging (RTI) is a computational photographic method that captures a subject’s surface shape and color and enables the interactive re-lighting of the subject from any direction in a software viewer, revealing details not visible with the naked eye. Learn more…

Need Some Help?

Let CHI experts advise you on your imaging challenge. CHI offers customized consulting services to both institutional and private clients, with special rates for nonprofit organizations. Projects of all sizes can be accommodated. Learn more…

Need Training?

CHI offers training in Reflectance Transformation Imaging (RTI) and photogrammetry. Learn more about these classes. You can also write to training@c-h-i.org.

Training by CHI

$50 suggested donation

Question? Ask on the CHI Forums

CHI offers a free discussion forums site where you can share your questions, insights, and issues as you work with Reflectance Transformation Imaging (RTI). Join the conversation!

RTI Workflow Materials

» Capture

  • Download the guide and the glossary
  • Watch the instructional videos

» RTI Highlight Capture Starter Kit

  • Order the RTI Starter Kit

» Process: RTIBuilder

  • Download the guide and example files
  • Download RTIBuilder

» View: RTIViewer

  • Download the guide and example files
  • Download RTIViewer

Related Publication

“Dynamic Shading Enhancement for Reflectance Transformation Imaging”

In this published paper appearing in the ACM Journal on Computing and Cultural Heritage (JOCCH) in 2010, the authors propose a set of dynamic shading enhancement techniques for improving the perception of details, features, and overall shape characteristics from images created with RTI techniques. More …

View: RTIViewer Download Version 1.1

RTI View  

Once you have captured (see Capture) and processed (see Process: RTIBuilder) your RTI images, you can use the information on this page to learn how to view them.

Download the Free and Open Source RTIViewer Software, Sample Files, and User Guide

The RTIViewer enables you to view and explore Reflectance Transformation Imaging (RTI) files at very high resolution (Polynomial Texture Maps, Hemispherical Harmonics Map, and Multiview RTI). You can view image files stored on your local file system, and remote files through HTTP.

RTIViewer Version 1.1 Apple/Mac logo Intel Macs
RTIViewer Version 1.1 Windows logo Win32
RTIViewer Version 1.1 64-bit windows logo 64-bit Windows OS (Windows 7 and above)

Windows users on a 64-bit OS will note improved performance and the ability to load larger RTI files.
RTIViewer User Guide 1.1 (PDF) Acrobat PDF logo
Note: the User Guide is also contained in the software download. Updated versions may be available on this page in the future. The User Guide includes installation instructions.
Glossary of Photographic and Technical Terms for RTI (PDF) Acrobat PDF logo
Version 1.0. Defines and explains terms related to the setup, capture, and processing of RTI images (308 KB)
Example Files symbol for example files Ancient Papyrus.zip (6 MB) Ancient Papyrus from the Bancroft Library

Rock Art Petroglyph.zip (4.8 MB) Legend Rock State Park in Wyoming
License GNU license icon This software is available under the Gnu General Public License version 3. If you wish to receive a copy of the source code, please send email to info@c-h-i.org.
Previous version
CHI Archive icon Looking for the previous version (v 1.0.2) of RTIViewer and the user guide? See our Archive area.

Features in the 1.1 Release


Note: Please see the RTIViewer User Guide for more complete acknowledgments.

This tool, designed for cultural heritage and natural science application, was primarily developed by the Italian National Research Council's (CNR) Institute for Information Science and Technology's (ISTI) Visual Computing Laboratory (http://vcg.isti.cnr.it). The work was financed by Cultural Heritage Imaging with majority funding from the US Institute of Museum and Library Services' (IMLS) and National Leadership Grant Program (award number LG-25-06-010706). RTIViewer also contains significant software and design contributions from the University of California at Santa Cruz; the Universities do Minho in Portugal; Tom Malzbender, formerly of HP Labs; and Cultural Heritage Imaging.

The updated 1.1 version of the RTIViewer software and User Guide was partially funded by a 21st Century Museum Professionals grant from the IMLS, along with volunter efforts and private contributions. The Bookmarks feature added in the 1.1 release is based on work done by Leif Isaksen of the University of Southampton, UK. We would especially like to acknowledge the work of Ronald Bourret and Gianpaolo Palma for the development work for this release.

Viewing RTI images at the Fine Arts Museums of San Francisco

Viewing RTI images at the Smithsonian's Museum Conservation Institute.