Sunday, May 18, 2008

Barkay, Zuckerman, & Lundberg (p. 1)

Out of the clear blue sky on Wednesday morning last week, Bruce Zuckerman notified me that Gabriel Barkay was in town, & wanted to meet with me & see some of my antiquities. He also informed me of an imaging technique called Polynomial Texture Mapping (PTM), & wanted to see if there could be some mutually beneficial collaboration between my LMLK research, & their Inscriptifact database.

As I quickly learned, PTM has been around for several years. The executable currently offered on Hewlett-Packard's website was compiled on September 11, 2001 (something positive to counterbalance the evil of that day).

By Thursday night, I had constructed my first PTM file for Redondo Beach handle ID #62! This software enabled me to combine the 8 shots I normally take of each seal impression from alternate lighting angles, & then it renders millions of other versions of the seal by solving a biquadratic polynomial equation for the color values of each pixel, or what it expects the value would be based on the 8 known values.

It's fairly simple once you learn the basic concept. You construct an LP (light position) file, which is simply a list of all the filenames followed by their normalized Cartesian-coordinate values, preceded by the number of files:

C:\GG2\Museum\redondo\gg62_imp_n_crop.jpg 0.0 0.4 0.5
C:\GG2\Museum\redondo\gg62_imp_s_crop.jpg 0.0 -0.4 0.5
C:\GG2\Museum\redondo\gg62_imp_e_crop.jpg 0.4 0.0 0.5
C:\GG2\Museum\redondo\gg62_imp_w_crop.jpg -0.4 0.0 0.5
C:\GG2\Museum\redondo\gg62_imp_nw_crop.jpg -0.4 0.4 0.5
C:\GG2\Museum\redondo\gg62_imp_se_crop.jpg 0.4 -0.4 0.5
C:\GG2\Museum\redondo\gg62_imp_sw_crop.jpg -0.4 -0.4 0.5
C:\GG2\Museum\redondo\gg62_imp_ne_crop.jpg 0.4 0.4 0.5

The order of the coordinates is X, Y, Z. So the first one listed there, which was taken with the light positioned "north" of the seal (i.e., above the icon's head shining towards its tail), is "0.0" in the X-axis (it remains centered), 40% of the way in the positive Y-axis, & 50% of the way in the Z-axis (above the plane of the seal impression).

The PTMfitter executable runs under the old DOS environment (the Windows "Command Prompt" accessory program), receives the LP file as an input, & outputs a PTM file. When I used the original hi-res JPG files from the camera (3648 x 2736 pixels), each of which is about 2.5 Mb, the PTM file was about 90 Mb. This is too much for my computer to handle (probably due to my low-grade video card ... I don't play video games). When I reduced each of the original files to 10%, or about 15 kb each, the PTM file was only about 880 kb ... far more manageable.

There were a few learning-curve bumps along the way. My original filenames have uppercase ".JPG" extensions, & the program demands lowercase. Also there are several switches that the DOS command can take, but I found the default to be sufficient via trial & error. I also experimented with the XYZ values since I never recorded the actual positions that I held the light in.

Finally, you can drag the PTM file in Windows Explorer over to the PTMviewer executable, which will then launch a new DOS window, & also the viewer window. Here you can drag your mouse over a circle as if you're controlling a virtual lightbulb, & view the seal impression from any lighting angle. There's also a feature called Specular Enhancement, that alters the image in such a way that it looks glossy wet, sort of like the difference between a dry donut, & one with a thick, delicious layer of sugary glazed icing!

I'm hoping to create a special web page giving complete instructions for downloading the PTMviewer, but for now, I'm going to return to Dr. Barkay while it's fresh in my mind.

Dr. Zuckerman invited me to his West Semitic Research Project office, & Dr. Barkay, & also Dr. Marilyn Lundberg were there when I arrived at 10:25 Saturday morning (yesterday; there were several other people there as well). It was great to see them, but it's always such a treat to see Dr. Barkay. I know God cares about each of us very deeply, but there has to be a special heavenly spotlight on the man who led the excavation where the oldest Biblical texts were discovered! But it was a tremendous honor to be able to spend this time with them all!

Drs. Lundberg & Zuckerman showed me one of their specially constructed lighting domes. It's sort of like a miniature planetarium with 32 clusters of super-brite white LEDs evenly spaced in 4 levels at the 8 positions similar to the ones I use. It's controlled by the same electronic device used in model railroading to switch powered accessories. They were happy to show it to me because they're planning to ship it to the Oriental Institute in Chicago soon so the PTM technology can be applied to the vast quantities of artifacts stored there (particularly their cuneiform tablets).

They also gave me additional demonstrations of the software on their own laptop. It was nice to see what this new technology can do for researchers, but it's also nice to see the enthusiasm of these 2 people! They really enjoy capturing the best possible images of artifacts so that other people can study them from afar. It's refreshing because over the years, I've mostly worked with technically knowledgeable people in the engineering realm who just do it for a paycheck ... very much like prostitutes, & that's unfortunate.

Next, I began showing them my specially selected stuff (out of about 300 artifacts I currently own) ... things that I hoped Dr. Barkay would find interesting despite the thousands of artifacts he's excavated & studied over the years, things that I was interested in hearing his opinions on, & things that Drs. Zuckerman & Lundberg would find interesting &/or challenging to photograph.

The first thing I showed them was my fake LMLK handle that I made in Albuquerque back in 2004 at a symposium. This prompted Dr. Barkay to mention the fabulous replicas made by Kris Udd, which in turn prompted me to show everyone the Rosette replica he made at my request of one from Michael Welch's collection (ID #9) to commemorate my meeting with Jane Cahill last year. He was even more impressed with this one than he was with the LMLK replicas, & rightly so ... it's truly exquisite!

Next, I showed him the Buddhist jar fragment I acquired from the famous Bruce Ferrini collection, that was liquidated earlier this year. (I was surprised that nobody had ever heard of him!) This prompted a brief discussion of the only known complete jar, owned by Harvey Herbert, on display at the Living Torah Museum in Brooklyn. Dr. Barkay commented on how surprised he was to learn of it, & emphasized how rare it was.

If I recall correctly, which is doubtful, this was the first occasion for me to visit LMLK Dotcom on the laptop PC available there ... we were all gathered around one end of a large table. We referenced it several times throughout the morning, but it was very convenient to hear Dr. Barkay comment on an artifact, & then I was able to say, "Yeah, that's right here on this page of the website..."

At some point Dr. Barkay noticed the silver LMLK-ostracon ring I was wearing on my hand, & I told him it was a gift someone got for me when visiting the Eretz Israel Museum near the excavation site of Tell Qasile. I was able to load the LMLK Ostraca page, & we discussed whether or not the 2 that were found there were authentic. Dr. Barkay expressed complete confidence that they were authentic, though I suggested that the non-LMLK one that mentions "gold of Ophir" might have been forged to follow up on the notoriety of the authentic LMLK one. I think it was Dr. Lundberg who commented on the completely different Mems indicating that it was forged, but Dr. Barkay said it was not likely that a forger would incise 2 different ones, & that to the contrary, this indicated that it was genuine.

Now that I think about it, this may indicate 2 different scribes--one who wrote "LMLK" as a sort of signature before or during the transaction, & another who wrote the rest of it during, or possibly afterward ... or vice versa. It's impossible to say because the artifact is obviously fragmentary.

Next, I showed everybody a special pair of LMLK handles, ID #s 63 & 64. In one of the E-mails I had exchanged with Dr. Zuckerman prior to the meeting, I said:

"Another important application for PTM in my own research is with handle matching. As you know, most LMLK handles are individual specimens, & aside from David Ussishkin's tremendous work at Lachish, very rarely have excavators been able to restore them. However, it would be nice to know which handles found at a site might have once belonged to the same 4-handled jar. Here are 2 sample pages in which I considered many aspects of a pair of unprovenanced handles:

ID #s 63 & 64

ID #s 36 & 37

Ultimately, it would be nice to have a database of PTM photos from each site, or at least from the major sites like Lachish, Rahel, Gibeon, Nasbeh, & Shemesh, so we could take the number of handles, analyze their wheel-rings & other criteria, & scientifically narrow down how many jars they actually represent.

I was able to go to the Handle Matching page, & briefly discuss these other factors. By the way, all the time I was showing these artifacts, Dr. Barkay was jotting down notes in cursive-Hebrew in a thick notebook ... it looked like it was already about 3/4's full on this occasion.

Next I showed the deeply impressed H2D handle I mentioned earlier (ID #62) along with a very shallow one that can't be identified (ID #61). Until just now, I didn't realize that out of my 68 LMLKs, I had taken these 4 consecutive numbers (61-4)! Dr. Barkay noticed the marks near the shallow icon's tail that seemed to form the head of a Mem, but he agreed that they were probably coincidental. I can see them now, but until he pointed them out, I had not noticed them. And he observed all of these things without the aid of a magnifying glass; I was very impressed!

Next I showed him 3 non-LMLK handles:

He spent some time analyzing this latter specimen, & commenting on it. He had written a chapter in Avigad's "Jewish Quarter Excavations vol. 1" about similar 8th-century B.C. incisions, & though he had no doubt about its authenticity, he noted that he had never seen this particular form. Although sometimes a letter or letter-shape was incised on bowls, he did not believe this was a letter (I referred to it as a "Vau-Incision" on the web page I made for it). I think it was Dr. Lundberg who asked if it could've been a potter's mark, but Dr. Barkay said it definitely was not, because a potter would've marked it before firing it, whereas this was incised after the firing. He noted that the incision ductus looked authentic, because the method used back then was with a tool shaped like a flat-head screwdriver made of bronze or iron.

By the way, I just want to interject here that I don't really care about the authenticity of any of these non-LMLK artifacts. The main reason I collect them is to study specimens similar to the real ones that are usually not displayed in museums, because they're generally not considered works of art that would impress the average Joe visiting a museum. It's less expensive for me to buy one, than it would be for me to travel to a museum, & hope the curator would allow me to examine their archive. I'm also planning to publish them in LMLK vol. 2, & I don't want to waste my time trying to get permission to publish specimens from provenanced excavations, & then have to pay for a photograph that doesn't show what I want to show.

Other non-LMLK items I showed on this occasion that I've not published yet:
  • an ostracon with an ink inscription (practice hieroglyphs of an Egyptian "A"; Dr. Barkay identified it as Hellenistic-era script)

  • a bowl/cup with a linear alphabet incised inside of it (similar to Aramaic incantation bowls; all 3 scholars said they had never seen anything like it, though there is one clear Tet ... an "X" within a circle, which was shared with the early alphabetic scripts)

  • a hematite cylinder seal with cuneiform wedges & typical glyptic art including a 2-winged light (I think it was Dr. Zuckerman who noted that X-rays could help determine the authenticity since mass-produced fakes would have a single perforation, but genuine ancient specimens or good modern fakes would've been drilled from each end slightly out-of-sync with each other when they meet in the middle; Dr. Barkay agreed with me that the wedges looked fake, or at least carved by a different person, & I think it was Dr. Lundberg who noted that sometimes the artist would carve the scene & leave a blank space for whomever bought it)

  • an all-wire seal with a duplicated inscription (for lack of a better description; Dr. Barkay was not able to decipher the script; he suggested it may be from an eastern culture, but it was of a type that would be heated up & used for branding farm animals)

  • a plastic button made by Charles Goodyear's India Rubber Company, with an 1851 patent mark (a great item for PTM photography because of its curvy & shiny surface)

  • a finger-ring with a scaraboid seal with the shallow incision of a menorah (Dr. Barkay noted that he wasn't an expert on menorahs, but if it's genuine, it's of the early type without the crossbar connecting the branches; the ring has a wire running through the scarab's perforation, & I asked if there were any chance it could be genuine since I doubted such a delicate construction could've survived all these centuries; he said that my specimen didn't look genuine, but he has personally excavated some that were still intact!)

  • a rectangular cuneiform tablet on which the text wraps around one edge from front to back (Dr. Zuckerman attempted to read it, but it's not an easy tablet to read)

  • a small, broken fragment from a cuneiform tablet's outer "envelope" with seal impressions

This is a good "breaking" point ... much more next week!

Song of the week: "Good To See You" by Vangelis (click the song title to visit Amazon; click here for a 30-second sample; 393kb).
G.M. Grena

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