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Using DStretch on tattoos.
This is an excellent article on the use of DStretch to make tattoos more visible.  If you are bothered by images of a deceased body don't view.
The article gives detailed instruction on how to use many little known DStretch features.  Well done.

RA 2022
                    Presentation Rock Art Near Cerro Murciélago, Baja
                    California Sur
I gave a presentation about the rock art near Cerro Murciélago in Baja California Sur for Rock Art 2022. The presentation was recorded and I was given the recording.  So here it is.
Interesting in this presentation is the presence of (I believe) children's paintings alongside the larger Great Mural figures.  So Great Mural painting was a family affair, not a secret shamanistic ritual.

DStretch ARARA tutorial
I did a DStretch tutorial for the ARARA Lecture series on 2/12/2022.  It was well attended, over 200 zoom participants. Here is the video that ARARA recorded.

Yale Egyptology The Woman's Monastery at Atripe - Epigraphic Survey
Some of the plastered walls at Atripe preserve traces of painted Coptic writings (dipinti) written by female monastics who recorded their names and details about their titles and positions, their concerns and activities, and their interpersonal relationships.  The authors use DStretch to see the writing.

Art image
I think (but I may be biased) that DStretch can create some beautiful images, not only from rock art. Here are some DStretched images I took from my phone.  They are not from rock art.

DStretch finds ancient Roman Villa
DStretch Marks  The First Roman Villa Discovered in Australia?

England's recent dry(ish) summers have created perfect conditions for subsurface features to become visible in Google Earth imagery. This page identifies parch marks which have been manipulated using the Rock Art image enhancement package DStretch. The software separates pigments of differing characteristics and allows the operator to display the optimum contrast. Jon Harman's DStretch software is simple to use and can produce useful results for analysis and presentation - as evidenced below - it is, in some instances, revelatory.
Michael B. Owen

Bateucas visit
This article appeared in the Bay Area Rock Art News, Summer 2019.  It chronicles our visit to the valley of Las Batuecas guided by Professor Julián Bécares Pérez from the University of Salamanca in Spain.  We visited a number of famous rock art sites, known in the time of the Abbé Breuil. Since posting this I have learned that Sheila was not the first to discover this site. Alfonso H Morán informs me that Marta Pantrigo Barés discovered it in 2010.

El profesor Ángel M. Felicísimo gana el CONCURSO DE FOTOGRAFÍA “WIKI SCIENCE COMPETITION 2019” en España

UNEX.ES  /El profesor del Departamento de Expresión Gráfica del Centro Universitario de Mérida, Ángel M. Felicísimo, ha ganado el concurso de fotografía Wiki Science Competition 2019 en España organizado por Wikimedia, en el que los participantes deben crear imágenes relacionadas con la ciencia y subirlas a Wikimedia Commons bajo una licencia libre. La fotografía se realizó con equipamiento de la Universidad de Extremadura.

DStretch is back on Android with a new name: aDStretch.
Otherwise it is the same app.  Google disliked the use of the name android in the app's name.

                    Diego Union-Tribune story
Technology is revealing area's hidden rock art

This article
appeared January 10, 2019 in the San Diego Union-Tribune, Pomorado News.  Greg Erickson, president of the San Diego Rock Art Association, is quoted about the rock art on boulders in Rancho Bernardo and Poway.  He gives a history of research and describes how DStretch reveals nearly invisible rock art.  Greg has been using DStretch on the boulders around San Diego and reporting his amazing finds at the San Diego Rock Art Symposium for many years.  He gave myself and a few others a tour of the boulders in 2017.  One mistake in the article needs correction.  Now neither the DStretch plugin nor the apps for iOS and Android are free.

New Buddhist rock art at Wat Phraphuttachai revealed by DStretch
I met Noel Hildago Tan at Red Lily Billabong in Australia in 2011.  Since then he has done incredible work in Southeast Asia, see the entry below on Angkor Wat.  I recently came across his site
SEA Arch and his description of using DStretch in Wat Phraphuttachai, Saraburi, Thailand:

"It wasn’t until we got back home and started to analyse our pictures with DStretch that we realised that one section of the wall with fragmentary paintings was actually a massive and magnificent image of the Buddha! Like the Phraphutthachai image, this Buddha is also life-sized but is more embellished."

Chavalito Slideshow
El Chavalito is a large Great Mural site in the Sierra de Guadalupe, Baja California Sur.  It was one of the first sites I visited in the Sierra de Guadalupe and it made a strong impression on me. The rock art here is fascinating and can be very beautiful. It is a significant site for the study of Great Mural art.  In some ways it is a companion site to Los Clavelitos.

DStretch Workshop May 29, 2017
DStretch Workshop
DStretch Workshop May 29
There will be a DStretch workshop May 29, 2017 in conjunction with the DStretch exhibit at Canyon Crossroads Museum, Melba, ID.  Visit the Canyon Crossroads Museum Facebook page to register.
DStretch Exihibit at Canyon Crossroads Museum
DStretch exhibit at Canyon Crossroads Museum, Melba, ID.  "Seeing the Invisible: Rock Art and DStretch", opens May 1, 2017, in conjunction with Idaho Archaeology and Historic Preservation Month.
Senda Rupestra
Senda Rupestra
This site has some great high resolution panoramas of rock art sites in Baja California Sur.  It is an excellent resource for those interested in Great Mural art. Sites documented: Cueva Pintada, Las Fletchas, La Soledad, Boca de San Julio, Los Musicos, San Gregorio, El Brinco, El Raton, La Serpiente, Cuesta Palmarito, San Borjitas, Piedras Pintas
Finally Great Mural art is available for all to see.
Clavelitos Page
Los Clavelitos
This is a very important site in the southern Sierra de Guadalupe.  With the upgrade to html5 I hope that more people will be able to appreciate this fantastic site.  In 2007 when I visited it I had no idea that such an important site would still be unknown in the literature (except for Del Cover's paper from 1990) after almost 10 years.  This seems wrong.  One cannot understand Great Mural Art without knowing about this site and other huge Great Mural sites in Guadalupe.  I hope this documentation can help.  This site is similar to the great sites in the Sierra de San Francisco in that it has hundreds of paintings including huge figures.  It is different in that the painters who visited this site reflect the large diversity in styles in the Sierra de Guadalupe.  This diversity just doesn't exist in San Francisco.
San Borjitas
I am upgrading pages that use flash to html5.  First off is:
San Borjitas  San Borjitas is a key site in the Sierra de Guadalupe.  The superimpositions there determine a chronology for Great Mural styles.  This is vital for my theory of Great Mural Migrations. I have upgraded the visual index.  Using this index is a great way to answer questions about the figures in the ceiling. You just click on the part of the ceiling you want to see in detail with enhancements.
I have also upgraded El Dipugón.  A beautiful site with fantastic creatures from the land and sea in amazing colors:red, black, white, yellow.
                    Güéribo Grove
In Search of Padre Ugarte's Güéribo Grove.  I gave this talk at the Yerba Buena California Native Plants meeting in San Francisco May 11, 2016.  It documents a mule trip I did in March 2015 searching for the grove that Padre Ugarte logged for timber to build the ship El Triunfo de la Cruz in 1719.
Announcing the AndroidDStretch app for Android phones and tablets. It has all the functionality of iDStretch.  It is available on Google Play.Google Play Store
A warning is in order: Unlike the iPhones camera quality and image processing can vary a lot for Android phones.  Make sure your phone takes images with sufficient quality for DStretch.
Announcing the iDStretch app for iPhone and iPad.  It is fast, simple and easy to use.  You can save the enhancements.  Use it in the field to visualize faint rock art. It has 8 enhancements that cover all pigments commonly seen at rock art sites.  Use it at home (as I do) on an iPad to take another look at enhancements of my favorite sites.
It is available on the Apple App Store.  App store
ARARA Las Cruces Logo
DStretch Workshops 
Due to popular demand I am giving two workshops this year on Thursday, May 26 2016 at the ARARA meeting in Las Cruces, NM.
                    Hein's DStretch WorkFlow
Gary Hein's DStretch Workflow
Gary Hein has kindly created a suggested workflow for DStretch.  It is a pdf and includes the workflow, operation instructions and a colorspace selection guide.  Thanks Gary!
Chickering Style 7 Site

On September 26, 2015 the Sacramento Archaeological Society and FSRA had a field trip to see Style 7 petroglyph sites in the Sierras.  We had a unique chance to visit the Chickering site on the North Fork of the American River.  Thanks to Dan Foster for organizing the trip and to John Foster for inviting me.  John Betts, the premier documentor of Style 7 sites was there.  It was great to see him again after many years.  DStretch did not always work to enhance the sites, but at Chickering it did well.  For more information on northern Sierra petroglyphs visit this link.
Burham Canyon Slideshow
Lately I have been updating my slideshow software.  The Burham Canyon slideshow is an old one, dating from the beginnings of DStretch.  I have now included in the slides pictures from a trip to Burham Canyon by KCAS (Kern County Archaeological Society) led by Jack Sprague.  Modern digital cameras and modern DStretch enhancements make a big difference.
Migrations of the Great Mural Artists
I have given a variant of this presentation at several conferences in 2014 and 2015: Balances (in La Paz, BCS for the first time), Rock Art (San Diego), MORAW (Zzyzx), SCA (Redding), SAA (San Francisco), and IFRAO (Cáceres, Spain).  I think it is an important use of Rock Art to document the migration of peoples.
Me receiving award
 SCA Award
At the same 2014 SCA meeting I received the Helen C. Smith Award.  I am very grateful for the recognition from SCA and to Mary Gorden for the nomination.  In 2005 I presented a poster about DStretch at SCA.  This was the start of DStretch.

Jon Harman

Recipient of the 2014 Helen C. Smith Award for Avocational Society Achievement.

SCA Proceedings
SCA Proceedings Paper
My SCA 2014 paper is published online in the SCA Proceedings.  This has text that supplements the presentation slides (Balances, Rock Art 2013 and SCA 2014) that I have on the DStretch Presentations page.
Here is a link to the pdf:
Harman, Jon, 2014, "A Tale of Two Cañadas: The Most Northerly Great Mural Site Yet Discovered," 28:206-218.
Ankor Wat DStretch makes Fox News! (But they don't call it DStretch).  Hidden paintings revealed at ancient temple of Angkor Wat
The journal article that the news article references is: Antiquity Volume: 88  Number: 340  Page: 549–565: The hidden paintings of Angkor Wat, Noel Hidalgo Tan, Im Sokrithy, Heng Than and Khieu Chan.
I met the first author (Noel Tan) in 2011 in the Northern Territories in Australia at a NAU field school for which I gave a DStretch workshop.  In the journal article he gives proper credit to DStretch.
There are more images available at the Time web site :  See 7 Hidden Paintings Found at Angkor Wat  I see that there are many sites picking this up, but none calls it DStretch.  The description they use is "decorrelation stretch analysis".
Rock Art, Balances 2013
Balances, Rock Art 2013 and SCA 2014

A Tale of two Cañadas: The most northerly Great Mural site yet discovered.   This presentation describes a new Great Mural site in the Sierra San Borja, the northernmost classic Great Mural site known.  I contrast the great mural site with nearby abstract sites and conclude that the Great Mural site could well be later than the abstract sites.  Presented at Rock Art 2013 in San Diego, November 2, 2013, INAH Balances Conference in Guadalupe Valley, November 22, 2013, and a shorter version at SCA 2014 in Visalia, March 22 2014.  I have since learned (and I should have known) that Rancho Cordonices was further north.
St Croix
St. Croix River Pictographs

In July, 2013, on a paddle down the St Croix River not far from Minneapolis my wife Sheila noticed some pictographs.  I had to borrow a camera, but got photos that I later DStretched.  This was an unexpected delight.  We later talked with Jean Schaeppi-Anderson, Cultural Resource and Interpretive Specialist, St. Croix National Scenic Riverway about the pictographs.  I sent her my enhancements.  I hope they help to document this beautiful site.
Donner Pass
DStretch on the Donner Pass Petroglyphs

On the weekend of June 22-23, 2013 BARARA held the Paul Freeman memorial field trip to the Sierras.  We visited many sites that Paul had led us to and found a site that Paul had been unable to revisit.  It was a great trip.  At the Donner Pass petroglyph site DStretch proved its usefulness.  I usually discourage users from getting their hopes too high when using DStretch on petroglyphs.  This time the pink granite patina gave DStretch a hue difference to enhance.  It worked well, even giving some new information not found in the drawings at the site plaque.

IFRAO 2013 Logo

IFRAO 2013 Talk on Patterns of Figure Placement in Great Mural Sites near Santa Gertrudis

I'm back from Albuquerque where I gave a talk in the session GREAT MURAL TRADITIONS OF THE AMERICAN SOUTHWEST organized by James Farmer and Dito Morales.  It was a great session.  Interesting that they have hijacked the Great Mural name (coined by Harry Crosby for Baja California) to include somewhat disparate styles from the American Southwest (Barrier Canyon, Pecos River, Grand Canyon).   María de la Luz Gutiérrez Martínez gave a talk on the Great Mural styles in the Sierra de Guadalupe, one of three talks on the Great Mural region in Baja California she gave at this conference.

China paper

Crack Patterns Morphology of Ancient Chinese Wares  (9mb PDF)

This very interesting paper by Sophia Lahlil, Weidong Li, and Ji Ming Xu of the Shanghai Institute of Ceramics of the Chinese Academy of Sciences uses DStretch to visualize the crack patterns of glazed ceramics.  ImageJ image processing software is used to analyze the morphology of crack domains.

It is a novel use of DStretch and judging from the illustrations, DStretch works very well to make the crack patterns visible.

The paper appears in The Old Potters Almanack, volume 18, number 1, June 2013.

Paul Freeman
Paul Freeman Gallery
Paul Freeman passed away Sunday, January 20, 2013.  Paul cofounded the Bay Area Rock Art Research Association almost 30 years ago.  I have been on so many rock art trips with Paul that it is impossible to count them.  His passing leaves a big void in my life and for our rock art club.  I have put together a gallery of photos of Paul, mostly on rock art trips. As I reviewed them I was reminded of the recent passing of Carolyn Toner, who was also a mainstay of our group and is in many of these photos. Paul's obituary is at the end of the slide show.
Gordon Wasson
Gordon Wasson, Reid Kaplan, Keewaydinoquay Peschel speaking about Miskwedo (Amanita Muscaria).  In addition to my interest in rock art I also like identifying and gathering mushrooms.  These tracks were taken from a tape given to me by longtime BARARA member Paul Freeman of San Francisco.  A friend of his taped this at the conference "Hallucinogens in Native America" held in San Francisco 9-28 to 10-1, 1978.   I think this tape is fascinating and want to make it available to others.
Rincon de las Cuevas Slideshow
New slide show: Rincón de las CuevasThis show is intended for specialists.  This site, the most northerly of the "classic" Great Mural sites is mentioned in Crosby but not illustrated.  Here are my photos and DStretch enhancements.  Unfortunately the preservation is very poor with much of the painting completely gone.  Nevertheless I think the enhancements help to give a pretty good idea of the imagery in this cave.
Selfic Tutorials
New DStretch Tutorials by Daren Sefcik

Daren Sefcik has written an excellent set of DStretch tutorials including videos.  I have been too lazy to update my ancient tutorials so Daren is filling an important gap.  Thanks Daren!
At the bottom of each tutorial are links to others.

Eel River Site
Eel River Petroglyph Site near Coleman Creek
I have an interest in petroglyphs as well as pictographs, especially along the Eel River in Northern California. Here are photos I took in April and September, 2012.
Globe and Mail
Globe and Mail article on the use of DStretch in Canada

An article about DStretch and its use by Parks Canada to make aboriginal pictographs visible.
(A related Parks Canada article is here.)

Siarb logo
DStretch Workshop at the International Rock Art Congress hosted by SIARB, La Paz, Bolivia, June 25-29 2012
See the SIARB web site for more info: http://www.siarbcongress.org/
SCA logo
DStretch Workshop at the SCA meeting in San Diego Thursday March 29, 2012
See the SCA web site for more info:
I will also give a talk: "Three Pictograph Sites near Mission San Borja, Baja California" on Friday March 30.


Canadian Geographic article on historic graffiti revealed by DStretch

Historic graffiti. 
New technology reveals details of rock inscription left by Simon Fraser
By Brad Himour
April 2011 issue

Arara 2011 Conference Logo
DStretch Workshop at the ARARA 2011 Conference in Idaho Falls

7 pm Thursday, May 26, 2011
Shilo Inn Conference Center in Idaho Falls

From the ARARA web site:
For the 2011 ARARA Conference, Jon Harman will conduct a 2-hour workshop on DStretch — the ImageJ plug-in he developed for image enhancement which is now being used worldwide. This hands-on workshop will be held on Thursday evening at 7 p.m. at the Shilo Inn in Idaho Falls. Using images from around the world, Dr. Harman will discuss the basics of DStretch enhancement and more advanced topics. Bring your computers! Dr. Harman will install DStretch for those who don't have it and will help you to get the best enhancements from your own images. The workshop fee is $20 and can be paid along with your Conference registration.


Talk at SNRAA October 25 2010 in Las Vegas

I will give a talk about rock art in the Kondoa region of Tanzania.  There will be lots of pictures of rock art and DStretch enhancements.

Rock Art 2010

 Rock Art 2010 Conference in San Diego Nov 6

I will give a paper about San Borjitas at the conference. 
I will give the same paper Nov 7 in Ensenada at the Balances 2010 conference.
Here is the abstract:
Cueva San Borjitas: Birthplace of the Great Mural Tradition.

Cueva San Borjitas is located in the Sierra de Guadalupe near Mulege, BCS.  It has over 80 anthropomorphs on its ceiling painted in the Great Mural Tradition.  The styles found in San Borjitas are quite varied compared to the Great Mural sites of the Sierra de San Francisco.  There are anthropomorphs in Cueva San Borjitas that are similar in style to the Sierra de San Francisco sites, but these are superimposed over other styles unlike anything in that sierra.  This provides strong evidence that the Great Mural Tradition started in the Sierra de Guadalupe before moving to the north.  This talk will examine the different styles and figure superpositions at San Borjitas.

The work presented in this talk is part of a project by INAH archaeologist María de la Luz Gutiérrez in the Sierra de San Francisco and Guadalupe.

 DStretch Workshop March 25, 2010 at the ARARA Del Rio Meeting

Here is the ARARA announcement:

DStretch Workshop - Jon Harman will conduct a 2-hour workshop on DStretch  (see dstretch.com) - the ImageJ plug-in he developed for image enhancement and which is now being used worldwide. This hands-on workshop will be held on Thursday evening at 7 pm at the Ramada Inn, Del Rio. Using images from around the world Dr Harman will discuss the basics of DStretch enhancement and more advanced topics. Bring your computers! Dr Harman will install DStretch for those who don't have it and will help you to get the best enhancements from your own images. For more information or to sign up, please send an e-mail to Donna Gillette (rockart@ix.netcom.com). The workshop fee is $20 and can be paid at registration.

DStretch Cuba Paper Primera aplicación de DStretch-ImajeJ. Mejora automatizada de imagen digital en el arte rupestre cubano.

Rocks of Ages Exhibit Announcement
This exhibit has moved to:
Maidu Interpretive Center 1960 Johnson Ranch Drive
Roseville, California 95661 (916) 774-5934
Exhibit continues through December 2009

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