Rock Art Digital Enhancement

DStretch is a plugin to ImageJ written by Jon Harman.

                    Conference Presentations

Information about
                  getting DStretch on Phones and Tablets

                animated image

DStretch Slideshows Documenting Rock Art


DStretch Help
Mode d'emploi de DStretch
(The French version of help is quite old, sorry.)

DStretch News: Click to view the latest DStretch events and additions to the web site.

DStretch can bring out faint pictographs that are invisible to the naked eye.  It works on digital camera images.  No special filters or lighting are needed.  To see what it can do check out the slide shows, especially Rocky Hill and Tulare.  More Rocky Hill images are in the RA 2006 presentation on Rocky Hill.  The ARARA 2007 presentation has some beautiful images from Kachina Rockshelter in Nevada.     My wife Sheila and I visited Tanzania in 2009.  DStretch worked very well as can be seen in the Masange slideshow.  I have done much work on the very important Great Mural site Cueva San Borjitas.  I gave presentations about this incredible site at SAA 2011 in Sacramento and ARARA 2011 in Idaho falls and Rock Art 2010 in San Diego and Balances 2010 in Ensenada and have a slideshow about it here.

DStretch uses decorrelation stretch.  This is an image enhancement technique first used on aerial photos.  For an explanation of how it works see the algorithm description.

DStretch is a tool for rock art researchers who wish to enhance images of pictographs.  It is a plugin to ImageJ.
ImageJ is an image processing and analysis program written in Java.  It needs to be installed first before you can use DStretch.
It runs on both MACs and PCs.

Make a contribution (below) and email DStretch@prodigy.net to get DStretch.
It is best to use a personal email address.  Many institutions do not allow the DStretch plugin attachment.
A contribution is mandatory before I will send the plugin.
  It may take me a few days to respond, have patience.
Unfortunately there have been too many requests and too few contributions for me to continue to give it away.
Please note that the plugin is not an app.  It has much more functionality than is possible in an app on a smartphone.
The apps are available from the Apple App Store (iDStretch) or Google Play Store (aDStretch).
Contribution is $50. Use the Donate button below.

If you want to send a check email me for my address.

Current version is 8.41. 

Contributors will receive new versions as they come out.

DStretch plugin written by
Jon Harman.
At Rancho Bernado Style site. Photo by Jeff LaFave
At Rancho Bernardo Style site (photo by Jeff LaFave)

Jon Harman
Piedras Pintas
At Croc-Marin with Michel Rey
At Croc-Marin in Fontainebleau, France with Michel Rey

Remembering Alvin R McLane

Alvin McLane and

Alvin McLane died October, 2006 in Reno Nevada.  An obituary is here.  Without doubt Alvin was the premier rock art researcher in Nevada.  I went on many rock art trips with Alvin and will miss him greatly.  I have put together a slideshow of my pictures of Alvin.   At NAA in Ely, Nevada I gave a presentation on Alvin's last road trip.  At the 2007 ARARA meeting in Billings, Montana I gave a presentation on Kachina Rockshelter, a place I visited with Alvin on the trip.  Alvin and I intended to write a paper on the sites we visited.

Amanita Muscaria Presentations on Amanita Muscaria by Gordan Wasson, Keewaydinoquay Peschel, Reid Kaplan.  Recorded at the conference "Hallucinogens in Native America."