You asked me to post my settings and I posted the exact settings. They are truthful.
Now, in the interest of the whole truth, I will discuss Swordmaker's comments. He has some valid things to say, but he is completely off base in saying I am dishonest.
First, his valid comments: He says my offset is too high on the shroud picture. He is correct that the offset is higher than anything you would use on a photograph. So how did I choose it?
The simple answer is I played with the parameters to produce an effect similar to the internet images. I didn't consider the technical aspects, only the visual similarity in results.
The parameters I used for the Obama and x-ray images are much more conservative. It is possible to get some 3D effect on the shroud image with conservative settings; it's just not as pronounced. And even with conservative settings, the shroud image is sensitive to angle, as is the Obama image. But not the x-ray.
You asked me to post my settings and I posted the exact settings. They are truthful...
...First, his valid comments: He says my offset is too high on the shroud picture. He is correct that the offset is higher than anything you would use on a photograph. So how did I choose it?
I realize that there are inherent difficulties in internet dialog and communication, but it is still very puzzling that it took around fifty excruciating posts to extract this oblique statement of your methodology in the face of factual, persisent and pointed questions about it. Science is in large part about METHOD, and the technical aspects of the method are critical to arriving at sound scientific conclusions. Clarity and transparency about the methodology we are using is necessary and vital to avoid misunderstanding and confusion, and to draw valid conclusions.
From 287: First of all the Photoshop filter is not an exact equivalent of the VP-8 analyzer. Whether this is important, I don’t know.
1. True, and 2. It is important to distinguish between the two.
The best source of information I found on the subject asserts that digital manipulation can be exactly equivalent to the VP-8 analog device.
Yes, but not Photoshop. Photoship Emboss is not one of that category. Emboss does not work by merely plotting image intensity in the Z axis as does the VP-8. More on that in a minute.
The images available on the internet are rather low resolution jpeg versions. The combination of low resolution and possible jpeg artifacts makes any definitive claims bogus.
The images studied by the STURP scientists are not low resolution jpeg versions.
I stand firm on several claims. First, the process of forming a 3D image from a single flat image is inherently interpretive. You cannot get the 3D effect simply by manipulating contrast. The “extrusion” effect is created by introducing implied light and shadow. That is what leads the human eye and mind to interpret an image as having depth. This processing is not objective. When you do this to an image you are in some sense falsifying the data.
If you are talking about an image made with light, that is correct. But if you are talking about the Shroud that is to assume your conclusion because the Shroud image itself was not made with light.
Second, images formed by a process similar to x-rays do not have any “angle of incident light” information. For this reason you can choose any arbitrary angle in the Photoshop filter and get equally plausible results.
Third, images formed by incident light, such as the Obama image, are sensitive to angle, because light and shadow are objectively embedded in the image. The emboss filter will not produce equally plausible effects with arbitrary angles.
That's what we've been trying to tell you. Albedo images filtered with Emboss will not be isomorphically accurate in depth and height.
Fourth, my honest playing with the shroud image leads me to the conclusion that is has embedded information implying an angle of incident light.
Again, we ask, what is the angle? Can you give a degree, so that we can test your hypothesis?
It does not have or require an angle of incident light because the Shroud image itself was not made with light. As proved here, in a source that both you and I have cited: http://www.shroud.com/pdfs/orvieto.pdf
I will listen to anyone who has a complete technical description of the VP-8 algorithm or the Bryce algorithm. I’m betting that they have a parameter equivalent to the Photoshop angle.
Listen to the VP-8 developer's description of it:
The VP-8 Image Analyzer is an analog video processing device. The “isometric display” is generated on a cathode ray tube, like that of an oscilloscope. It is like a home television set, except the scanning and positioning of the video image is controlled by electrostatics (voltages), rather than by electromagnetism (currents). The picture is monochrome, or black and white, television. However, the isometric image is “shades of green” rather than “shades of gray”, due to the type of the cathode ray tube used.The isometric display uses the changes of brightness, as they occur in an image, to change the “elevation” on the display. If something is bright, it goes up. If something is dark, it goes down. If it is some gray shade in-between, it produces an “elevation” inbetween something very bright and something very dark.
The isometric display was never intended to produce a “real-three-dimensional” display. A snow-covered peak would look like a high, flat surface, while a rock sitting on top of the snow would look like a deep hole in the high surface. Light reflecting from a stream at the bottom of a valley would appear to be a high elevation, perhaps even higher than the snow on the peak of the mountains. Dull rocks and dark vegetation would appear to be lower than the water of the stream. In other words, objects are not as tall or short, high or low, as their reflectance of light might indicate. There is no correlation between reflectance and altitude.
The purpose of the isometric display was to make it easier to follow patterns of changes in shades of gray within an image. Particularly, the light pattern changes in reflection of light from soils and vegetation near a fault line were of interest. Following patterns of soil types and vegetation types was also of interest. But in no case was there ever any indication on the isometric display of how high or low, how tall or short something was. In looking at the facial area of the ventral image of the Shroud of Turin, one observes a generally proper “ramping” of the nose, a “rounding” of the face, and “shaping” of the lips, eyes, and cheeks. The isometric display is mapping responses to light energy, but the result induced by the image is altitude-relevant. This is a unique response.
The VP-8 Image Analyzer can vary the elevation scale (Z axis) relative to the X and Y axis scale. The VP-8 cannot change the linearity of the Z axis response, unless the unit is un-calibrated or the camera is improperly operated. A change of 10 percent in the incoming light level will produce an elevation change of 10 percent on the Z axis. It is a direct, linear function. The VP-8 can change the image polarity from bright-is-up to bright-is-down, but this is simply changing photographic response from negative to positive polarity. Therefore, a photographic positive or negative can be used, if the isometric polarity control is properly selected.
The Shroud image induces a response in the isometric display of a VP-8 Image Analyzer that is unique. Each point of the Shroud body image appears at a proper “elevation”. Is this due to the distance the cloth was from a body inside it? Is this due to the density of the human body at various points in the anatomy? Is it a result of radiant energy? These questions cannot be answered by the VP-8 Image Analyzer. However, the related theories can be rightfully posed. The isometric results are, somehow, three-dimensional in nature. The displayed result is only possible by the information (“data”) contained in the image of the Shroud of Turin. No other known image produces these same results.
The VP-8 Image Analyzer’s isometric display is a “dumb” process. That means it does one process on whatever “data” is sent to it. In that regard, it is quite like Secundo Pia’s photography. The photons come from the image through a lens, onto the sensitive material in a television camera. The photons are converted to electrons, causing more voltage to be present where the picture is bright and less voltage where it is dark. The isometric display plots out bright and dark as elevation. Like a photographic negative, the process is not “involved” in the result. It is simply photons in and voltage out. The Shroud image induces the three-dimensional result. It is the only image known to induce this result.
http://www.shroud.com/pdfs/schumchr.pdf
[excerpts][emphasis mine]
If I had to sum up the difference between Photoshop emboss and the VP-8, I would say that Photoshop's pseudo 3D effects on albedo images via the emboss filter is to the VP-8 what a parrot's mimicry of human speech is to human language. There are superficial similarities, to be sure, but that's where the resemblance ends.
Sixth, I have learned a lot from arguing this controversy. I’m always willing to be wrong or partially wrong. I simply haven’t seen much to convince me that I am wrong. I have had to narrow my claims. Take that as a victory if you must.
I have learned things about the Shroud, too, that I did not know before. There nothing necessarily wrong with being wrong about something in science, as long as no one is hurt by negligent application of the error, and if the error leads to knowledge. As far as I can tell there are no injuries or fatalities that have resulted from this discussion. The only ultimate victory is Truth.
I am agnostic as to what the Shroud respresents historically, although I acknowledge that there may exist information of which I am ignorant that renders my agnosticism unjustified. I do tend to disagree with the hypothesis that the Shroud is a medieval forgery. If it is a forgery, it is certainly one of such phenomenal accuracy and detail as to provoke shock and awe at the artistic mastery of any putative medieval forger. It also seems unreasonable, in light of the uncertainty of the accuracy of the radiometric dating that was performed on the Shroud previously, to positively date the artifact as of Medieval origin when one cannot even say how the image was formed.
Cordially,