We can probably discard the conventional claim that a 3D plot
cannot be produced from a conventional photograph.
The thumbnail pictures to the right are four examples of death masks from a PowerPoint presentation put together by Joseph Accetta, which may give us a preview of his upcoming presentation in St. Louis. He tells us:
Shadowing is apparent in all of these images except perhaps the leftmost one. None of the other images would render a 3-d reproduction with a vp-8 or similar instrument.
ImageJ is in agreement. The first of four photographs plots very nicely. We get good 3D from a conventional photograph. The other three, not so good.
Click on the photograph to enlarge it
How did I find all this? Colin Berry found it. He commented in Anticipating the Conference: Joseph Accetta on 14th Century Origins:
Try downloading this PowerPoint presentation from Joseph Accetta, David (he being the subject of a recent posting here, and one of STURP’s genuinely scientific, non-agenda driven, non grandstanding participants in my view).
(Unzip as if a pdf).
Go to the last few pages (approx 24/25). There you will see model spectroscopic (ir) studies not just with thermally-imprinted scorches, but also with linen that has been chemically dehydrated with 36% H2SO4 and even your invisible ink (lemon juice).
I’d be the first to admit there may be little to distinguish between an image produced by chemical as distinct from thermal dehydration (especially if chemical action was heat-assisted – see Luigi Garlaschelli’s model ‘frottage’ imprinting with acid-contaminated red iron oxide). It’s the vehicle for acid that is important (not too runny, not too viscous).
Some of us eagerly await details of what JA will say at St.Louis. Let’s hope it receives more attention than his meticulous and detailed studies to date.
Nuff said. I’m thinking of doing a post dedicated entirely to JA (he being my kind of scientist).
Nice find, Colin!
We get good 3D from a conventional photograph. The other three, not so good.
Not true!!! Just look what I have done with those images in ImageJ (using high smoothing for visualisation purposes -it lowers high narrow peaks like noises and edges):
http://img845.imageshack.us/img845/4757/5slu.png
http://img839.imageshack.us/img839/2416/gna3.jpg
Remember NEVER use original colors or grayscale in Image J. Due to specific projection it MAY BE VERY MISLEADING!!! Use Spectrum/Fire or Thermal LUT instead!
I agree, just compare it to the shroud image posted on the previous thread. It’s like night and day.
I also find the fact that all the images selected has no hair , mustache or beard to avoid any shadows from further distorting the image in 3D. Nice try ;-)
Mike, I agree with you in a qualitative sense. But the classic claim that a 3D plot cannot be produced from a conventional photograph is hard to defend in a general sense.
O.K. I understand why not to use original colors because it includes the underlying image. Is grayscale, here different than gray?
Dan, achieving realistic 3D information from an art work is also hard to defend. Achieving it from a photograph properly lit (with no shadows) is possible but not as good as the shroud. Claiming that someone would achieve that technology with no apparent reason (to avoid the shadows) and only the one time and no process evolution or any documentation in the Middle Ages is impossible.
A lot depends on the angle at which you view the face. The more closely you approach the vertical, the more closely any 3D image of either a photograph or a portrait resembles its subject. From the side, they usually look pretty weird (see http://shroudstory.com/2011/03/30/new-3d-rendering-of-the-shroud-of-turin-face-by-john-chen/ for a different program just for a change). I said before somewhere that almost any full-face, evenly lit, dark background, monochromatic portrait produces an image which is at least as good, and often better, than the shroud does.
I have just this minute posted some graphics showing what happens when model 2D “shade charts” are entered into ImageJ.
http://colinb-sciencebuzz.blogspot.fr/2014/06/not-all-images-that-are-3d-enhancible.html
3D effects, some quite spectacular, are achievable despite there being no encoded 3D information, except that is for the, er, cheiropoietic gradient in image density.
Dan: O.K. I understand why not to use original colors because it includes the underlying image. Is grayscale, here different than gray?
Yesterday I wrote:
“Every image is 3D, as it has 2 spatial coordinates + intensity (X,Y,I). The point is that the intensity I correlates with cloth body distance (which is also imprecisely defined – Jackson, Jumper & Ercoline used simply vertical, or Z distance).”
So I discourage using original colors or greatscale and rotating 3D models, as the shape of it may be distorted by the persepective from which we observe it. So the true-3D images (defined like above) may not look 3D, or opposite not-true-3D may look like true 3D.
The best way is to use Thermal LUT with infront view like here:
http://ok.apologetyka.info/upload/ap_upload/articles/15/2013/06/rysunekxxii.jpg
The color scale (which is quite objective ) serves for 3D. It is like looking at topographic map. You must then analyze whether the shape looks like real human body, of course taking a linen laid on him into account.
Photographs never satisfy this, as far as I tried -they always have too ‘hot’ foreheads due to them being large flat surfaces.
I don’t know how you feel that the picture in your llnk demonstrates any satisfactory 3D encoding. If the pale blue areas are supposed to be approximately the same height off the the base, then the forehead doesn’t curve, and is as flat and as high as the cheeks, the hair, and the area under the moustache. There is no curve to the sides of the cheeks, just an abrupt ‘cliff’ from pale blue to dark blue. The highest areas, presumably the contact areas if we set aside Piczek’s floatation model for the moment, are in green and consist solely of the tip of the nose and the beard, not the hair or anywhere at the top of the head. Even if we postulate that the white areas are also contact areas (so the distance/intensity hypotheses breaks down), then the brow still is not an area of contact. However one interprets this image, it clearly shows that the the 3D encapsulation is very poor, and certainly not as good as anybody who wanted could create with a bit of sepia chalk. You are quite correct that to get any good kind of 3D image from the shroud it is best not to look at it from shallow angles: but this is because it’s not a very good 2D to 3D image, not because of the software.
Hugh:
I don’t know how you feel that the picture in your llnk demonstrates any satisfactory 3D encoding.
It is a little bit qualitative rather than quantitive evaluation. Do not consider green areas -those are almost certainly surface contamination, blood & dirt etc. White areas are most probably contact areas, nose, beard, eyebrows, cheeks, front of the forehead. Bluer areas are farther than that. The sides of the cheek are in the dark bands, or are either covered by some headband, or perhaps it is due to the darker bands passing there.
You should also consider smoothness of the brightness curve -compare to the contact scorch images on the left (from Głowacki).
Generally it needs some experience to know what to look for, (and what not to look), but one can easily see that the Shroud image is distinguished in comparison to others. Only Craig & Breese images have quite similar effect, I do not yet fully understand why.
Generally, I think about putting a kind of a gallery of 3D images comparing the Shroud and and its attempted reproductions. Had I only enough time for this…
Only Craig & Breese images have quite similar effect, I do not yet fully understand why.
Or maybe I do. Probably they simply thrown more dust in appropriate areas, imitating Shroud face at negative images. Yet still I think their artwork has inferior quality to theShroud, and is of course inconistent with many of the latter’s characteristics (lack of any paint, whether in liquid or solid dust form being the first of them).
There is an ongoing project to build a 3D model based on random conventional photographs. I think i’ve already commented this issue.
With only one random conventional photograph? No way.
The shroud image is NOT holographic but is NOT a mere photograph.