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The oldest footprints outside of Africa: an interview with Dr. Sarah M. Duffy about the imaging of this incredible find

Sarah Duffy, PhD is a Postdoctoral Research Associate at the University of York in the Department of Archaeology. In May of 2013, after a series of storms, ancient footprints were revealed on a beach near Happisburgh (pronounced “Hays-boro”) on Britain’s east coast in Norfolk (see a 6-minute video). The footprints were fragile and washing away a little day by day. Sarah was called to the site by Dr.

Why a Nonprofit? The Seeds of CHI

We often get asked why we set up CHI as a nonprofit. I can understand the question, because we are doing some pretty high-tech projects, and we work with a number of famous institutions whose names people recognize, perhaps making us seem grander and better endowed than we really are. There are a number of reasons why a “public benefit charity” structure made sense to Mark and me when we founded CHI in 2002. The greatest impetus for it was a personal vision we shared.

New Work in RTI: A report from recent conferences and meetings

I have had the good fortune to attend a few recent events that allowed me to see some really useful work other folks are doing in our field. I thought it worth a blog post to mention a few with some links.  I’ll note that I have seen even more cool stuff, but if there wasn’t a paper or a page I could link to, I decided not to include it here. First, Mark Mudge and I were at Computer Applications and Quantitative Methods in Archaeology (CAA) in late April in Paris.

CHI Welcomes Tom Malzbender to the Board of Directors!

Tom Malzbender imaging a piece from the Antikythera Mechanism We are absolutely thrilled to announce that Tom Malzbender has joined the Cultural Heritage Imaging Board of Directors! Tom is a long-time friend of CHI and has been an adviser and collaborator on many projects. Tom is best known as the co-inventor (with Dan Gelb) of Polynomial Texture Mapping (PTM) in 2001 while he was at HP Labs. PTM is the first form of Reflectance Transformation Imaging (RTI).

NEW: RTI glossary now available

Over the years we have received a lot of requests for a glossary of terms used in RTI, and we are happy to announce that a new “Glossary of Photographic and Technical Terms for RTI” is available on our website!  It includes photographic terms you need to know for RTI, like “Depth of Field,” “Color Temperature,” and “Aperture.

A big thank-you to our donors!

What an encouraging way to end 2013: our Annual Giving campaign raised almost twice as much as the previous year! Our donors’ continued support of Cultural Heritage Imaging (CHI) is both touching to us personally and vital to our mission. Our donors’ gifts enable CHI to develop innovative digital imaging tools and practices and disseminate them to experts and students all over the world.

Behind the scenes: RTIViewer 1.1 release

We are thrilled to announce the release of the RTIVewer  1.1 software! This update release includes the most asked for features in the RTIVIewer.  As with prior versions, this is free, open source software. We have been working with it for a while, and we are excited to get this out to everyone in the RTI community. I am most excited about surfacing all the numerical settings data within the interface.

Adam Rabinowitz’s blog post on digital surrogacy

Adam Rabinowitz’s Blog Post “The Work of Archaeology in the Age of Digital Surrogacy” is a brilliant thought provoking piece, and I couldn’t resist reposting here. At CHI we have been wrestling with issues of scientific imaging and process history and what it means to be a digital surrogate for many years.

Behind the Scenes of a New English Heritage guide for RTI

Guest Blogger: Sarah M. Duffy Ph.D. Serendipitously while completing my Master’s in Historic Preservation at University of Texas at Austin, I met Carla Schroer and Mark Mudge of Cultural Heritage Imaging (CHI) at the 9th Annual US/ICOMOS International Symposium being held in San Francisco in 2006 where they were demonstrating the application of an innovative recording technique based on a mysterious shiny black ball.

Thank You Tim Lindholm!

Tim Lindholm, circa 2004 I want to take a moment to thank outgoing board member, Tim Lindholm.  Tim served on the CHI board from its inception in 2002 and has been an enormous help to us over the years.  In addition to being a constant source of good questions and good advice on the board, Tim  designed the electronics and power systems of CHI’s early automatic dome systems.

Rock Art Recording

Mark shooting photogrammetry sequence at Petroglyph National Monument During the month of May we had the pleasure of doing more imaging work with Rock Art .  This has included shooting some Reflectance Transformation Imaging (RTI) and some photogrammetry sequences at a couple of different sites.  More importantly, we have had a chance to present some of this work to folks researching and recording rock art.

In honor of Debbie Ward

In the summer of 2012 I lost a dear friend of more than 20 years to lung cancer. Debbie’s and my friendship began in the workplace in the late 80′s, and blossomed into so much more.  We hadn’t worked together in more than 20 years, and yet we stayed in close contact and got together for regular dinners every couple of months. Debbie was a remarkable person in many ways, but if you asked her what the most important thing she ever did was, she would say being a mom to Katie.

Join us! New Free Forums for the RTI Community

This week we are rolling out CHI’s new free forums  for the community of people who are developing and adopting Reflectance Transformation Imaging (RTI) and related computational photography. We have had the idea to do this for some time, and after trying a couple of different forum software packages, getting input from friends, and tinkering with some of the forums setup, we are now ready to invite the larger community. Join us! Sign up for a forums account now: go to http://forums.

CHI celebrates 10 years as a nonprofit corporation!

On August 16, 2002 we founded Cultural Heritage Imaging as a nonprofit corporation in San Francisco.  Wow, it seems like yesterday and it seems like a long time ago!  Our digital camera at that time was 3 megapixels and it had a pretty slow auto focus. We had seen Tom Malzbender’s pioneering Polynomial Texture Mapping paper at SIGGRAPH in 2001, and we began working with him several weeks later.

Announcing brand new CHI website!

We recently unveiled a brand new website at It has been in the works for a while (these projects always take longer than you want them to…) There is a lot more information about our current work, and we hope you will find that the new menus and navigation make it easier to find things you are looking for. There are a few things I would like to highlight.