Archive for the ‘3D’ Category

Is there an art historian in the house?

December 13, 2014 14 comments

imageColin Berry did an interesting 3D rendering from the painting "Descent from the Cross with the Holy Shroud" or as it is sometimes called, “The Entombment of Christ” by Giovanni Battista della Rovere (c. 1575-c. 1640).  The question must be asked; how much has this painting been enhanced from the original? To what extents did this alter the 3D rendering. To see why we need to question this, look at the copy on the website of the Shroud Museum in Turin (see clickable thumbnails below).

The bigger question may be: how accurate is this popular web version (center below) as a useful indicator of what the shroud looked like in the early 17th century.  Should we not be using the photograph that is on the Shroud Museum website.

ImageJ Rendering from the Giovanni Battista della Rovere painting shown here in the center. The "Descent from the Cross with the Holy Shroud" or “The Entombment of Christ” by Giovanni Battista della Rovere painted about 1625, as it appears in many websites on the web. As it appears on the website of the Church of the Holy Shroud and the Shroud Museum where the painting is located. As photographed Nov 6, 2008. The web size is 2585×3396 meaning you can have a good close look.

imageNote:  Paul Vignon attributed the above painting to Giulio Clovio (1498–1578) and a different painting, shown here on the right, to Giovanni Battista della Rover.

Is there an art historian in the house?

Only the Shadow knows

December 12, 2014 75 comments

The apparent 3D in the picture to the right was created by the arc of the sun.
The green color was photoshopped in for illustration purposes only.

imageA reader points out:

[Colin Berry wrote], “Takeaway message: there is no encoded 3D information in a photograph of the TS. There is merely a 2D image that has patterns of light or dark that can be computer-processed to give APPARENT relief. But if the original image was not created by photography, but by some other imaging mechanism, there is always the possibility that one will be fooled into thinking that a darker-than-average feature on the image represents high relief. It ain’t necessarily so. Different imaging models create different interpretations.”

He is right. Colin has shown one way that apparent relief can be generated that has nothing to do with shape. Dan, do you remember Nathan Wilson and his Shadow Shroud?  He showed another way to create a 3D image that had nothing to do with it.

How could I not remember Nathan.  We debated briefly on an ABC Radio program.  He got the better of me that day and made me look foolish.  Nice guy, though. And yes, you are right, he did demonstrate another way to generate apparent relief. Apparent is the essential word, however.

imagePersonally, I don’t think what we see on the Turin Shroud is only apparent relief.  I think it is real relief. I think the grayscale values (my preferred term for brightness, darkness, intensity, luminosity, shade, density, etc.) represent that. Regrettably, the only evidence I see for this is that it seems so. “It seems so” is one step lower on the evidence quality ladder than “I think I see.”  Moreover, I have no reason to think that the grayscale values of the shroud images represent distance between the outer surface of the body and facial hair and a burial shroud above and below it. My gut says it is so. Occam’s razor is a great temptation. But in the end there is really no evidence for the scene we imagine.  Could it not just as easily be distance from a hypothetical plane that intersects the body from head to toe, so to speak?  Or relative distance to some point in space? Those notions are harder to imagine because we can’t imagine an action-at-a-distance scenario for them. We have imagined a scenario to go with body to shroud distance. Well, sort of, maybe.

Speaking of imagined scenarios:  “John Jackson’s ‘Fall-through’ hypothesis for image formation belong to the class of hypotheses that invokes the action of photon radiation” (newest Critical Summary 2.1 out of Colorado, page 73). Are we to measure brightness in terms of distance or measure it in terms of time that the cloth spends falling through a mechanically transparent body?  And then  there is Frank Tipler’s hypothesis of dematerialization by electroweak quantum tunneling, in which a “proton plus electron goes to neutrino plus antineutrino.”  Is this a measure of anything that we can comprehend? Tipler, in his book, The Physics of Christianity implies it is distance by telling us that at the time of dematerialization of the body, the cloth is perfectly flat.

And of course we can’t imagine inexplicable non-process miracles; the touch of a hand or finger, a few spoken words, or a seeming unrelated unusual activity all serve as examples. In the New Testament Jesus changes water into wine, a woman is healed when she touches Jesus’ garment, Jesus feeds a multitude with five loaves of bread and two fish. Where is the process in these? What imagined actions are taking place.?  More recently, there is the apparition of Mary appearing to Juan Diego; Mary had arranged flowers in Juan Diego’s cloak and when later he opened his cloak in the presence of a bishop the flowers fell out leaving behind an image now known as Our Lady of Guadalupe. Perhaps the image on the shroud is the result of an inexplicable non-process miracle like that.

Or let’s just suppose Colin is right and the image we see was formed by a hot template. Could the resulting variations in grayscale values  have been caused by varying temperatures in a large piece of metal?

In 2005, Nathan Wilson, experimented with a method he devised, a method for creating an image similar to the shroud.  This isn’t to suggest that this was how the image was formed. But it does show that so-called brightness (grayscale) maps can be generated by other methods that are not formed by action at a distance and that do not contain real distance information. Wilson writes:

The image on the Shroud is dark on a light background. Previous theories had all attempted to explain how linen could be darkened without the use of chemicals, stains, or paints. Wilson wondered if it would be possible to lighten the already dark linen, leaving only a dark image behind.The simplest means of lightening linen, available to all men throughout time, is to bleach it with sunlight. Wilson believed that if an image of a man were painted on glass with a light shade of paint, placed over darker linen, and left beneath the sun, a dark image would be left on a light background. More importantly, he believed a dark and light inversion would take place, creating a photonegative. Wherever light paint had been used, the linen would be shaded from the sun and left dark and unbleached. Wherever the darker shade of linen had been left exposed, the sun would bleach the cloth light. In addition, it was also believed that because the sun would be exposing the linen from approximately one hundred and eighty degrees, a crude three dimensional image would be created.

How 3D-ish are the images?  Colin’s, as well?  Those of the shroud?

Wilson’s Results

Oil paint on glass, produced by David Beauchamp in roughly forty-five minutes while watching stand-up comedy. This painting was the most successful and was used to produce three different images on linen.

The first linen image created by Beauchamp’s window, exposed for ten days generally parallel to the sun’s path. The linen bears a negative image, dark on light (left), which becomes positive, light on dark (right), in a true photonegative.

The second linen image created by Beauchamp’s window, exposed for fifteen days generally perpendicular to the sun’s path. The lines are much harder than those in the first image.

The third and final image created by Beauchamp’s window, exposed for approximately one hundred and forty hours beneath a sunlamp. The stationary light source created an image flat and scattered.

Beauchamp’s parallel shroud (right), and the Turin Shroud (left) both topographically rendered.

The Turin Shroud rendered three-dimensionally. Shabby chic.

The Beauchamp parallel shroud rendered three-dimensionally. Shabbier chic.

Should we be rethinking the VP8 and 3D images?

December 9, 2014 104 comments

Todd, a reader of this blog, just yesterday posted the following quotation from Peter Schumacher. It’s from a 1999 paper by Pete entitled Photogrammetric Responses From The Shroud of Turin.

The Shroud of Turin induces a [3D] result through photographic imaging that is unique, compared to all other photographic results taken from other objects of the same acknowledged period as the Shroud, of prior periods, and to the present day. It is the “data” existing on the Shroud of Turin, which induces the unique photographic results. Therefore, the Shroud image, itself, is unlike any other object or image known to exist. (Bracketed “3D” added by me for clarity)

imageThis obvious absence of evidence as evidence fallacy – call it what you want: argumentum ad ignorantiam, the black swan problem – has stood, it seems, since sometime after 1976, when (quoting from A Critical Summary of Observations, Data and Hypotheses – Version 2.1 by Bob Siefker, et. al.):

[John] Jackson, with the help of Eric Jumper (both on active duty and teaching at the U.S. Air Force Academy) used a VP-8 analog computer furnished by Pete Schumacher, an engineer with Interpretation Systems, Inc., to make a brightness map of the Shroud image.

Then they tried to do the same thing with photographs of people and objects. Pete tried. Others tried over the years. Everything else was distorted; no real 3D.  There was, among those who understood that a normal painting or photograph of a person or object contained brightness information that was representative of reflected light while the image on the shroud contained brightness information that was not that but rather seemingly spatial data, a sense that the argument was safe. It has been repeated and restated over and over by others.

“OK Hugh [Farey],” wrote Todd, “Maybe you can respond to this quote. I ask again that you provide published evidence to refute this claim.

As long as we continue to think of just regular paintings or photographs of people or normal objects – and we ignore the cries from the fallacy police – we are on pretty safe ground.  It cannot yet be refuted.

But Colin Berry didn’t do what others had done. He made a scorch of an object on cloth. And he found that that scorch behaved like (or pretty much behaved like) the image on the Shroud of Turin. Colin found a black swan and we couldn’t say any longer that all swans are white.

That is published evidence; it is published on Colin’s blog and reshown here. It is not a painting or a photograph of an object; it is a scorch.

If we continue to speak only of normal paintings and photographs we are still on safe ground. But we have to drop the idea that the shroud image is unique.  It isn’t.

Click on the images to see larger versions

While we are at it, maybe we can drop the other fallacy, namely that the 3D data represents body to cloth distance.  That has not been shown to be true.

ImageJ Used to Compare the Shroud of Turin and the Manoppello Image

June 14, 2014 25 comments

imageAs a guest posting, O.K. has put together an intriguing image-ladened paper, Shroud of Turin & Manoppello Image Comparison & 3D analysis: Or the magic of ImageJ.  

Jumping to near the end:

Suppose for a moment that both the Shroud and the Manoppello are authentic relics of Jesus. Being so different, they provide complementary information.  The monochromatic Shroud with it’s 3D properties provides a model Jesus outlook. It is essentially like an old sculpture. It provides information about shape of the object, but no other information like skin, eyes, hair colour.

But what [that] model needs is texture. And Manoppello, if genuine may provide it!

It is wonderfully fun to see how powerful ImageJ can be.


More on Colin Berry is up with an interesting posting about 3D enhancement

June 10, 2014 5 comments

imageColin Berry has been adding to his posting, Not all images that are 3D-enhancible have ‘encoded 3D information’. Click in and, if you have already read his posting, scroll down about halfway to Update: Sunday 8 June. He had made some interesting observations about ImageJ. Personally, I’m finding the software confusing and some options limited. Colin is helping all of us to see how confusing using ImageJ can be.

Final gasp (on this over-long posting): there was a curious and unexpected feature of those 3D images where 4 different images were tested together. Switching between Invert On versus Off in Image J did not produce so marked a transformation as expected (one expects the image to be turned inside out, like punching a hat to make a new one with the lining on the outside).

Read on. It’s not that I don’t understand Colin. I do. It’s ImageJ that I am struggling with. Having said that, however, I still think this package is much more powerful than the VP-8 Image Analyzer. Once we figure it out more completely, we may be able learn a great deal more about the image on the shroud.

Link to previous posting in this blog:  Colin Berry is up with an interesting posting about 3D enhancement

The above picture is from Colin’s site.

Speaking of 3D

June 8, 2014 10 comments
Categories: 3D, Image Theory

Colin Berry is up with an interesting posting about 3D enhancement

June 7, 2014 15 comments

By St. Louis, will it confusing to talk about 3D in conjunction with the shroud?

imageColin writes in his blog:

The Turin Shroud image is famously 3D-enhancible, given the right software. Initially it was shown with the so-called VP8 image analyser that was allegedly space-age technology, and not surprisingly led to much over-hyped speculation that the TS image was different from any other.

This  blogger pricked that particular balloon some 2 years ago, pointing out that the 3D- enhanced images not only brought the man’s image up out of the page, but the 1532 scorch marks as well. (Wikipedia credits me with making that finding, but I’ll try not to let it go to my head).

There’s more talk right now about what the modern day equivalent to VP-8 (freely downloadable ImageJ software) does or does not do to the TS image that is meaningful. In other words, what are the ‘correct’ settings that gives a valid image?

imageWe need to distinguish between 3D plotting and 3D enhancement. Colin took a cartoonish picture meant to be a depiction of sorts of Jacques de Molay, the Grand Master of the Knights Templar. Why, well read that in his blog. He then executed a rather simple 3D Surface Plot using the original colors to plot with. In other words he merely gave the picture some shape based on the relative luminance or brightness of every x/y coordinate in the picture.  That is 3D enhancement. I made a reasonably good imitation of it. It is the second picture and it looks almost as if I stole it from his blog.

But that isn’t really isn’t a legitimate plot. You need to use a monochrome color, not the original colors and not the grayscale (of those colors). There are two imageways to do this. First you can use the two monochrome colors the tool provides, blue and orange. Or you can load a simple flat color background as texture. I used a solid green background image. As you can see, the plotting yields very unnatural elevations.

imageFinally, you can use on of the Color Look Up Tables such as the Thermal LUT. O.K. has made this point in comments elsewhere. These can be very telling as the example on the left shows.

“[W]hat are the ‘correct’ settings that gives a valid image?”, asks Colin. I don’t know. But unless we sort this out there is going to be a lot of confusion.

Categories: 3D, Image Theory
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