|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. Although the DStretch plugin is free for amateur use, the apps for iOS and Android are not 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."
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.
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 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.|
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.
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.
|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.
|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.
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
It is available on the Apple App Store.
Due to popular demand I am giving two workshops this year on Thursday, May 26 2016 at the ARARA meeting in Las Cruces, NM.
|Gary Hein's DStretch
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!
Updated Slideshow: The Mysterious Creature in Burham CanyonLately 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.
New Presentation: 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.
SCA AwardAt 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.
Recipient of the 2014 Helen C. Smith Award for Avocational Society Achievement.
SCA Proceedings PaperMy 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.
|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".
|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.
|St. Croix River
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.
|DStretch on the Donner
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.
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
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
|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, 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.
|New slide show: Rincón de las Cuevas.
This 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.
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.
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 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.)
Workshop at the International Rock Art Congress
hosted by SIARB, La Paz, Bolivia, June 25-29
See the SIARB web site for more info: http://www.siarbcongress.org/
at the SCA meeting in San Diego Thursday March
See the SCA web site for more info: http://www.scahome.org/meetings_events/index.html
I will also give a talk: "Three Pictograph Sites near Mission San Borja, Baja California" on Friday March 30.
New technology reveals details of rock inscription left by Simon Fraser.
By Brad Himour
April 2011 issue
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.
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.
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 - 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 (firstname.lastname@example.org). The workshop fee is $20 and can be paid at registration.