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| Tags: 20040615, artifacts, background, boehringer, cosmic, deep, early, filament, mesh, murray, networks, noise, photos, rmforall, sky, structure |
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http://groups.yahoo.com/group/AstroDeep/6
background filament networks (Murray mesh) in deep sky photos-- noise artifacts or early cosmic structure? Boehringer: Murray 2004.06.15 rmforall 2004 June 15 Bob, thanks for your lucid and careful comments about the very reasonable interpretation that the faint background filaments noticable in the background of many extremely deep space photos at very high red shifts are possibly just noise. In response to your second post on the effects of raising gamma on making random noise more visible in photos, I want to point out that the "Murray mesh" threads are visible on deep sky astronomical photos with gamma at the usual value 1.00, as in the case of the recent Hubble images of Abell 1689. Why would random pixels become a mesh of thin, long, crooked, continuous threads? With a low-cost program MGI PhotoSuite 4, it is easy to use my 1.4 GH Pentium 4 system to switch from gamma .30 to 3.00 in steps of .10 gamma, and magnification from .25 to 4.00, examining the variously colored more prominent threads. They are quite persistent. They look to me like a scale invariant, fractile mesh, as predicted by current models of the evolution of initial large scale structure into filament networks around voids. If this is what we are viewing, then of course we are looking from inside a dense large-scale condensed region, within which our local cluster of galaxies has evolved, and so it would be expected that we would see the same dense network of filaments in all directions at a redshift earlier than the condensation of stars and galaxies in our region, since it is improbable that we would be located near the boundary of our region. So, the question of whether "Murray mesh" is artifactual or factual is worth exploring. The Touchup Filters also includes Invert, which reverses all the colors. Switching every second to Invert and back makes it easy to find delicate threads that are visible in both modes. Would you create a completely random 2 MB image with pixels evenly shared among white, black, violet, blue, green, yellow, orange, red, and put it on a site where anyone can copy it and look for similar artifacts? The striking 3D effect of looking with relaxed, slightly crossed eyes for a while at paired identical images, until a third image emerges between them, is my direct experience. I have successfully guided many others to also have it. It is quite striking to pick out two color postcards in a shop and see the third 3D image hanging in space between them. I surmise that some level of the brain's image processing is cued by the slight convergence of the eyes to carry out the 3D interpretation function, even though the images are identical. I find that I see much more in astronomical photos this way, even though the 3D quality may be somewhat off-- for instance, craters may be confused with hills. I'm interested in whether you and others report success or not in actually trying it with a number of photos. When I rotate both images 90 degrees or 180 degrees, I get the same effect-- a definite and enjoyable enhanced perception of the third image, quite different from focusing both eyes on a single image. I welcome civil debate on these images. Anyone can post to I had to place low-resolution JPG images in the archive at my discussion group http://groups.yahoo.com/group/AstroDeep/1 However, the filaments are even more convincingly obvious in the original TIFF images, up to 100 MB of color coded data, especially if the gamma is shifted from 1.00 to 2.00 or 3.00. They show up in images of different sky locations, with different wavelengths, various color codings, and from a variety of large telescopes. They are easy to see in color deep sky photos in popular astronomy magazines, especially when the gamma has been shifted to about 2.00 to render the black background more luminous. Try it with selections from the recent Hubble photo of Abell 1689 at http://hubblesite.org/newscenter/new...2003/01/image/ http://hubblesite.org/newscenter/new...003/01/image/f This 1.89 MB TIFF image at 1X or 2X clearly show myriad red and black filaments in what I intrepret as a deep 3D mesh, which can been seen behind as well as between the translucent foreground galaxies. I haven't seen any signs of gravitational lensing, which might be because they are too far behind the lensing cluster to be "in focus". The 3D effect with paired identical color photos is very striking for me-- I can do it with tourist picture postcards in a store. I'm interested in how many people can readily experience various versions of 3D perception this way. In mutual service, Rich ************************************************** ************** From: "Rich Murray" Subject: Hubble sees via Abell 1689 to 2 B ly 1.7.3 Date: Tuesday, January 07, 2003 5:01 PM Hubble sees via Abell 1689 to 2 B ly 1.7.3 Hubble Sees Deep Universe Using Cosmic 'Zoom Lens' Updated 2:32 PM ET January 7, 2003 By Deborah Zabarenko SEATTLE (Reuters) - Using a cosmic "zoom lens" made up of cluster of a trillion stars, the Hubble Space Telescope looked back in time to see the universe just 2 billion years after the theoretical Big Bang, astronomers said on Tuesday. Hubble's new Advanced Camera for Surveys looked straight through a massive galaxy cluster known as Abell 1689. The gravity of the cluster's trillion stars acts as a monster magnifying glass in space, warping and magnifying the light of galaxies far behind it. Abell 1689 is 2.2 billion light-years away, and it acts as a 2 million-light-year-wide "zoom lens" in space, scientists said at a meeting of the American Astronomical Society meeting in Seattle. A light-year is about 6 trillion miles, the distance light travels in a year. The new image appears at first glance as hundreds of jewel-like bright objects -- distant galaxies -- against a black background, much like previous Hubble pictures. On closer examination, there are faint arcs of red and blue, the light from even more remote galaxies smeared by the gravitational bending of the light as it is magnified. "We create a kind of pothole in the geometry of the universe," said Narciso Benitez of the Johns Hopkins University, referring to the warping known as gravitational lensing. Some of these galaxies have been seen before, but the new picture reveals 10 times more arcs than would be seen by a telescope on the ground, and makes an image twice as sharp as previous images from the orbiting Hubble's earlier cameras. Hubble scientists also showed a new image of the dusty disk around a nearby baby star where planets could lurk. The 5 million-year-old star -- a true infant in cosmic terms -- lies 320 light-years away in the constellation Libra and appears to be part of a triple-star system. Earlier Hubble images showed two rings separated by a dark lane in the star's disk, and this was interpreted as evidence of one or more planets around the star. The new disk image gives a more complex picture, revealing a tight spiral structure with two arms, one of which appears to be associated with a nearby double star system. In a color image, there is a black blob where the light from the star has been masked to highlight the disk. "In the picture, we're seeing an interaction between the binary system and the disk," said Holland Ford, also of Johns Hopkins. "We're not seeing planets in this disk, but there is nothing that would preclude planets in this debris disk." Hubble images and information are available at http://hubblesite.org/news/2003/01 http://hubblesite.org/newscenter/new...2003/01/image/ ************************************************** ************** From: "Louise and Bob" To: "Rich Murray" Subject: a friendly introduction: Beohringer: Murray 2004.06.12 Date: Monday, June 14, 2004 10:11 PM I went to the Yahoo groups and took a look at the photos. I have to say that I did not see any filaments. I was expecting to see something a little more obvious. Having worked for several years in image processing I was wondering how much of the photos you started with were information and how much was noise. For example, if an image has 8 bits of depth per pixel are there 4, 5, 6, or 7 bits f information. It is rare to have the lowest bit as actual information and in many imaging situations there are fewer than 6 bits of actual information. This means that the lowest 1, 2, and often 3 bits are noise, ie not information. Image processing is often the task of making images more pleasing to the eye. This can be simple as in changing the brightness or contrast. Gamma is a simple change of pixel intensity in which the change is greater to darker pixels than to brighter pixels. Suppose that the images are 6 bit images. That leaves 2 bits of noise. Alter the images so that 2 bits are information and 2 bits are noise and 4 bits are now nothing. What just happened to the information content of the image relative to the noise content? Also, these images are JPGs. That is a lossy compression method. How has that changed the noise content of the images? Check with the original source of the images to learn how much of the images is real and how much is noise. Knowing the quality of the images is important. Calibrating digital equipment is tricky. Lots of different techniques have been employed to adjust sensing equipment. I am a bit curious about the means of viewing 3-d when the images are identical such as in viewing multiple tv screens. The composition of images into an internal 3-d view by the brain requires that the eyes see slightly different images. I sometimes work in a virtual reality lab here at VT. The CAVE produces 3-d worlds by supplying 24 image pairs to the eyes per second. A different image is rendered for each eye. The same is true when a head mounted dsplay is used. Three-d movies do the same. Two televisions side by side or two telescope images side by side are not going to create the 3d effect sicne the images do not differ. SIRDS (single image random dot stereograms) produce a 3-d effect, but rely on the use of noise and low resolution images to produce the effect. Two superimposed images are laid over a noisy background. The eyes separate the low resolution images from the noisy background. The important point here is that two differing images are imbedded inthe single image. This is still different than a tv image. ************************************************ From: "Louise and Bob" To: "Rich Murray" Subject: gamma Date: Tuesday, June 15, 2004 8:43 AM The important first step is to consider whether or not the pattern in the images is real or not. This is before there is any discussion of redshift or distance or UV or anything else. So now I am going to avoid discussing tangled webs of distant objects and gravitational lensing possibilities and everything else like that. Step 1 is to see what gamma is all about. A common way of computing gamma is as follows: new = ((old/max)^gamma)*max Here max is the maximum value of a pixel. For simplicity of discussion consider max to be 255 which corresponds to the largest value when 8 bits are used. Dividing a pixel by max maps the pixels from 0 to max to the interval 0 to 1. Then the value is raised to the gamma. The number is still between 0 and 1. Multiplying the result by max stretches the data back out to the 0 to max range, which here is 255. So back to the original range of a pixel. The gamma value is not the number you entered. Typically it is 1/n, where n is the number you entered. Because gamma correction is a point process it is possible to precalculate what a pixel maps to. By point process it is meant that each pixel is independent of its neighbors. Local values do not affect the result. Each pixel is on its own. I attached graphs of the correction for gamma values of 2.5, 100, 200, and 300. Here is what happens. The 2.5 graph is a typical upper limit for corrections used with monitors. The other graphs are effectively identical. Take a look at the left side in the range 0 to 8. Assume 3 bits of noise. Noise is now raised to the level of bright. The 5 bits above the noise are all 0. There should not be anything in the image, yet applying gamma effectively shoves the noise pixels into the visible range. I think it is rather clear that the use of large gamma values on these pictures is generating nothing, but noisy images. If you want to dispute this you might try something like the following: Take all of the pixels in the image. Count how many bits are on and off. For example, take the highest bit. How often is it 1 and how often is it 0? If the bit is a noise bit it is conceivable that the number times that the bit is 1 is approximately equal to the number of times it is 0. Compare these results to the results for lesser bits. There is no 3-d possibility from identical images. The 3-d effect is based on the differences, apparent shifts, between the objects in the images. There are lots of optical tricks that can be played on the mind. Try this one. Take a pattern of random dots. Duplicate it. Shift the second patterns a small amount relative to the first random dot pattern. What do you see? Is this real or an artifact of the way in which the visual system tries to make sense of potential patterns. bob ************************************************** ************** a friendly introduction: Beohringer: Murray 2004.06.12 2004 June 12 Hello Bob, I enjoyed your website on stereology. You might be interested in my simple analysis of mysterious background filaments in very deep cosmological photos, for which I set up a group over two years ago. I am organizing myself to offer a post on recent images. "About two decades ago I noticed that when the same photo is set up side by side, and viewed with slightly crossed eyes to make a third composite image in between, that image is created by the brain's visual system as an excellent 3D image. In fact, you can visit a TV store, where a lot of sets are all on the same channel at once, and find two sets the same size, side by side, and watch the composite image in moving 3D. If you settle your gaze gently for a few minutes into the composite image, the innate image processing facility of the brain's visual system will develop and deepen the 3D appreciation in remarkable and beautiful ways." deep sky background filaments: images and interpretation 2002.01.19: Murray rmforall http://groups.yahoo.com/group/AstroDeep/1 http://photos.groups.yahoo.com/group....dir=/&.view=t Click on the thumbnail photos to get the photos, and click on those in turn to get full screen photos. Artifacts? Or?-- immense filaments of H, He, and dark matter, lit by intense UV from the earliest very massive stars, "...during the first 10E8 years of the history of the universe at redshifts between 50 and 10...," Prof. Richard B. Larson, Sci. Am. Dec 2001, and http://www.astro.yale.edu/larson/papers/Noordwijk99.pdf [7 pages]. This very early intense UV is now redshifted into the visible and IR bands, and may supply about half of the current cosmic IR background. The filaments are generally as thin as 1 pixel. Photo #2: deeptt1k.jpg: One pixel = .258 arc-sec, about .25 mm on my 15" monitor. In MGI PhotoSuite 4.0, I can zoom in to 1600 %, at which point each pixel is about 4 mm on my 15" monitor. This is a 20KB cut from the center of the 673 KB original, Photo #1: deeptt1.jpg: 1024X1024 pixels, a random sample, the first of three, a little to the lower left of center of the 1.15X1.15 degree field, 16000X16000 pixels, 750.3 Mb 24-bit color TIFF, the highest available resolution, http://www.noao.edu/image_gallery/html/im0637.html National Optical Astronomy Observatory Deep Wide-Field Survery. ************************************************** ************** ----- Original Message ----- From: "bob" Newsgroups: bionet.neuroscience Sent: Tuesday, May 25, 2004 5:43 AM Subject: Use of stereology How often do people make use of stereology in their research. If you do use it, do you use a software package or do you use a manual technique? http://filebox.vt.edu/users/rboehrin/index.htm http://filebox.vt.edu/users/rboehrin...boutAuthor.htm The Author I am Robert Boehringer and presently living in Blacksburg, Virginia where I attend Virginia Tech. I have been enrolled in the Masters program for Computer Science as a part time student. My GPA is 3.90 (A=4.0 A-=3.7) Although part time I am an active student and attend as many of the lecture series as possible. I also make good use of the cultural opportunities that are available through the university. I am employed by MicrobrightField, Inc. the leader in software for stereological research and serial reconstructions. Outside of the school and work I have hobbies that include bird watching, hiking, traveling, and the occasional rock climb. My motivation for creating information about stereology is due to the the lack of information available online. It also provides me the chance to record some of the observations I have made. It is surprisingly easy to find misinformation about stereology. Examples a Suggestions to avoid proper sampling Poorly done simulations The use of ocular mathematics The latter entry is in reference to a joke that several of us started in high school. It was suggested that the easiest math would be a discipline with a single axiom, "If it looks right, then it is right." It should come as no surprise that ocular mathematics is prevalent in many disciplines. Stereology is no exception. I have seen corrections for numbers that are too large, generate even larger numbers. I have seen counting rules changed to forms that were more pleasing to the eye. I have seen assumptions made about averages that do not hold under even the simplest conditions. I cannot be certain in all cases, but I believe that the ocular axiom was invoked in all of these cases as well as many others. Please send in suggestions or comments to . Tricouni Nail in the Needles of South Dakota This page written by Robert Boehringer at Virginia Tech. ************************************************** ************** http://groups.yahoo.com/group/aspartameNM/message/1071 research on aspartame (methanol, formaldehyde, formic acid) toxicity: Murray 2004.06.15 rmforall Rich Murray, MA Room For All 1943 Otowi Road, Santa Fe, New Mexico 87505 USA 505-501-2298 [ NutraSweet, Equal, Canderel, Benevia, E951 ] http://groups.yahoo.com/group/aspartameNM/message/927 Donald Rumsfeld, 1977 head of Searle Corp., got aspartame FDA approval: Turner: Murray 2002.12.23 rmforall ************************************************** ************** |
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