Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Sun, 17 Sep 89 20:30:14 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 17 Sep 89 20:29:49 -0400 (EDT) Subject: SPACE Digest V10 #54 SPACE Digest Volume 10 : Issue 54 Today's Topics: NASA Headline News for 09/08/89 (Forwarded) Re: How the "Face" imaging data was pro Re: NASA missions/time table Re: NASA designates 17 space grant colleges/consortia (Forwarded) Re: Linguistic Tidbits Re: Linguistic Tidbits How the "Face" imaging data was processed Neptune images - help with MAC-II data format Re: How the "Face" imaging data was processed ---------------------------------------------------------------------- Date: 8 Sep 89 19:06:01 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 09/08/89 (Forwarded) ----------------------------------------------------------------- NASA Headline News Friday, Sept. 8, 1989 Audio: 202/755-1788 ----------------------------------------------------------------- This is NASA Headline News for Friday, September 8.... Workers at Kennedy Space Center's Pad 39B are conducting a payload End-to-End Test today. The test is an important milestone in preparing for the Countdown Demonstration Test scheduled for next Thursday and Friday. The crew arrives at the Cape Tuesday evening. Two Soviet cosmonauts have begun to reactivate the Mir Space Station. Tass news agency reports that Alexander Viktorenko and Alexander Serebrov began to power up the spacecraft shortly after 2:00 A.M., Moscow time. Some problems were experienced in the automatic docking procedure and the cosmonauts were required to do the linkup under manual control. A Progress-M resupply vehicle preceeded the arrival of the Soyuz in late August. The two-man crew began to unload the Progress almost immediately. The pair of cosmonauts will be aboard the station for six months. Special modules will be launched in October and February to expand the working area of the station. The University of Alabama-Huntsville Consortium for materials development in space has set November 12 as the launch date for their second flight this year. Space Services of Houston will provide the sounding rocket which will take 12 microgravity experiments on a suborbital flight from the White Sands Missile Range in New Mexico. The rocket will reach 200 miles altitude, giving the experiment package seven to eight minutes of weightlessness. NASA's Ames Research Center, Genentech and Penn State University's Center for Cell Research will join in a program to expand understanding of the effects of microgravity on the human body. It's been found that microgravity accelerates reduction in bone calcium, body mass and immune cell function. It's hoped that the program, scheduled to start in 1990, will increase medical knowledge to treat human bone diseases, organ regeneration and transplantation as well as immune and skeletal muscle cell deficiency. * * * * ----------------------------------------------------------------- Here's the broadcast schedule for public affairs events on NASA Select television. All times are Eastern. Thursday, September 14..... 11:30 A.M. NASA Update will be transmitted. Friday, September 15..... 6:00 A.M. Final six hours of the STS-34 Countdown Demonstration Test with astronaut crew. All events and times are subject to change without notice. ----------------------------------------------------------------- These reports are filed daily, Monday through Friday, at 12 noon, Eastern time. ----------------------------------------------------------------- A service of the Internal Communications Branch (LPC), NASA Headquarters. ------------------------------ Date: 8 Sep 89 19:26:00 GMT From: tank!eecae!upba!damon@uxc.cso.uiuc.edu Subject: Re: How the "Face" imaging data was pro How about posting the reference to the original paper? ------------------------------ Date: 10 Sep 89 02:59:59 GMT From: jarvis.csri.toronto.edu!utgpu!utzoo!henry@rutgers.edu (Henry Spencer) Subject: Re: NASA missions/time table In article <4338@utastro.UUCP> terry@astro.UUCP (Terry Hancock) writes: > How would the RTGs handle an extreme high velocity reentry (or >atmosphere - crossing orbit, it might still leave the atmosphere of >course)? ... This is actually considered the worst reasonably-likely accident (since it takes pretty unlikely ones to break the RTGs open during launch). I believe the RTGs aren't tough enough to survive high-speed reentry plus impact intact. -- V7 /bin/mail source: 554 lines.| Henry Spencer at U of Toronto Zoology 1989 X.400 specs: 2200+ pages. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 10 Sep 89 03:21:16 GMT From: ibmpa!szabonj@uunet.uu.net (nick szabo) Subject: Re: NASA designates 17 space grant colleges/consortia (Forwarded) In article <31134@ames.arc.nasa.gov> yee@trident.arc.nasa.gov (Peter E. Yee) writes: [$75K first year, $225K+$100K fellowships in succeeding years for each college/consortia] This sounds great! The number of colleges and the dollar amounts look kind of small, though. Also, what will be the scientific and technical emphasis of the funded research? The press release only mentioned "engineers and space scientists". "Want oil? Drill lots of wells." J. Paul Getty -- -------------------------------------------- Nick Szabo uunet!ibmsupt!szabonj These opinions are not related to Big Blue's ------------------------------ Date: 12 Sep 89 18:33:04 GMT From: dinl!holroyd@handies.ucar.edu (kevin w. holroyd) Subject: Re: Linguistic Tidbits In article <1724@cfa237.cfa250.harvard.edu> mcdowell@cfa250.harvard.edu (Jonathan McDowell) writes: stuff deleted > >How about the rest of the solar system? I think that it's >Mercury: perihermes aphermes >Venus: ? >Mars: periares apoares >Jupiter: perizenon? >Saturn: perikronon? > >Any offers from classical scholars? Venus: ? ap hrodite :-) :-) -- ******************************************************************************* Kevin W. Holroyd * CFI Aspen Flying Club * Got tired of last .signature file Denver CO. * ******************************************************************************* ------------------------------ Date: 12 Sep 89 21:12:27 GMT From: bbn.com!ncramer@bbn.com (Nichael Cramer) Subject: Re: Linguistic Tidbits In article <1453@dinl.mmc.UUCP> holroyd@dinl.UUCP (kevin w. holroyd) writes: >In article <1724@cfa237.cfa250.harvard.edu> mcdowell@cfa250.harvard.edu (Jonathan McDowell) writes: stuff deleted >> >>How about the rest of the solar system? I think that it's >>Mercury: perihermes aphermes >>Venus: ? >>Mars: periares apoares >>Jupiter: perizenon? >>Saturn: perikronon? >> >>Any offers from classical scholars? > >Venus: ? ap hrodite :-) :-) I like this. As a brief aside, somewhere ("Intelligent Life in the Universe" ?) Sagan suggests the adjective "Cytherean" --from Cytherea, the island where Venus/Aphrodite was "born"-- to describe things connected with Venus. In part because the adjective form of "Venus" is "Venereal" and he refused to accept the neologism "Venusian". I always thought this very pretty, but I don't recall ever having seen it used. NICHAEL ------------------------------ Date: 8 Sep 89 08:47:34 GMT From: oliveb!amdahl!drivax!macleod@apple.com (MacLeod) Subject: How the "Face" imaging data was processed Several posters have expressed doubts about the techniques used to resolve the Martian "Face" imaging data. I read the original paper which describes the technique, and I was impressed with its cleverness. Of course, I have only a casual background in science, and this technique may be either in everyday use or obsolete due to better methods. Anyway, the imaging data is captured as an 8-bit word, yielding 256 shades of grey. The researchers took this data, and figuratively expanded each pixel into a set of nine pixels, as we will see. -----l-----l----- First consider a block of l A l B l C l nine adjacent pixels values l l l l labeled A through I: -----l-----l----- l D l E l F l l l l l -----l-----l----- l G l H l I l l l l l ----------------- Now consider the middle pixel in this group, E. The methodology expands this pixel value into nine values: -----l-----l----- l E l E l E l l-----l l 1 l 2 l 3 l l E l --------->>> -----l-----l----- l l l E l E l E l l-----l l 4 l 5 l 6 l -----l-----l----- l E l E l E l l 7 l 8 l 9 l ----------------- (Pardon the awful ASCII graphics) They then used a set of weighting algorithms to assign values to each new data point. Pixel E(5) has 100% of the value of the original E, whatever it was. Now, pixel E(2) is assigned a value calculated by adding 75% of the value of E(5) to 25% of the value of B(8) [or some other set of values adding up to 100%]. E(1) is assigned a value weighted somewhat differently; if E(1) were further broken down into more values, E(1,1) would logically be expected to have a value closer to A(9,9) than E(1,9), or E(5,1). So the weighting algorithm was adjusted to reflect this. You can see that it takes several passes to calculate and recalculate the correct values, because the first set of calculations must use the "raw" values for A, B, C, etc. Once preliminary averaged values for A(1-9), B(1-9), etc. have been resolved, finer calculations can be made. As I said, I thought this pretty clever. Information theorists tell us that there ain't no free data, but this comes close to looking like some sort of software holography yielding higher resolution by magic. After some reflection, I decided that if you compared the expanded image to a new image which actually captured nine times the data of the original image, it would be clear that what was produced was an average. Where the "real" data differed, interestingly, would be in gradations of detail which were (for our purposes) nonlinear - where an abnormally bright spot was somehow juxtaposed, for whatever reason, with an abnormally dark one. But there's nonlinear and nonlinear - if the data added in the "real" high-detail imaging is nonlinear, can it be thrown away as noise? I know the answer is no, but I don't know why with any certainty - possibly because the signal to noise ratio is so high and the sample range is so small that the distinction between noise and data is hard to make. I appeal to those of you with greater experience and knowlege to help me out here and explain the merits and inherent problems with this fascinating methodology. (I immediately tried to apply the concept to digital sound, but didn't get anywhere...but it's an interesting thought!) Finally, as kind of a control, the researchers took a heap of 8-bit data from a terrestrial imaging satellite and processed it. The resulting image very closely resembled a photograph taken from a far lower altitude, so they were encouraged. The paper contained many images, including the "control", and was quite entertaining. Michael Sloan MacLeod (amdahl!drivax!macleod) ------------------------------ Date: 8 Sep 89 20:54:26 GMT From: oliveb!tymix!opus!thomson@apple.com (Bruce Thomson) Subject: Neptune images - help with MAC-II data format Can anyone please explain the format of the MAC-II ("ProViz" I believe) image files in detail? I would like to write a program to display them. I don't have a MAC or compatable graphics program From memory, the descriptions that I saw refered to an array of "grey-scale" pixels. Each byte in the file is apparently one pixel. Does the value of the byte represent a "grey-scale" density? If this is the case, the file sizes are too small. I think that I remember the images where something like 640 by 480 pixels. This would result in a file size of 307200 bytes. The files vary in size, but some are far too small if this is the case. What I need is a clear and detailed description of how the data in the files maps to the image to be displayed. I imagine that there are other people like myself that would like to see these pictures, but don't understand the data structure of the files. ------------------------------ Date: 8 Sep 89 20:39:05 GMT From: kr0u+@andrew.cmu.edu (Kevin William Ryan) Subject: Re: How the "Face" imaging data was processed > macleod@drivax.uucp says: > [ Long description of 3x3 pixel duplication and averaging to blow up the > original 'Face' data. Statement that this appears to "almost be producing > new data." ] Yeaarg. Ick. Well, now that the visceral response is done with... When you do pixel duplication expansion of an image (copy original to an image 3 times the size, with each pixel replicated in a 3x3 area) followed by averaging (replace each pixel by the average value of its area) YOU DO NOT PRODUCE NEW DATA! It may appear that you have a better, more detailed image, what you have is simply a larger image. You have not improved resolution at all. Nyquist criterion - you can record/reproduce/extract information that is up to half your sampling frequency. An image can record details that have edges containing spacial frequencies up to a wavelength of 2 pixels. In other words, you can only record an edge that varies from one pixel to the next. If you blow up the image by a factor of X you now have an edge transition that occurs over X pixels. You have _no_ sharper detail. Any edge transition occuring over less than X pixels, however you may manipulate the data, is empty enhancement. It wasn't in the original. If someone tells you otherwise, they may ask you to buy a bridge next. Side note - there are methods of examining the frequency function of an image, and doing an analytic extrapolation of the function to produce a resolution greater than sampling, since the frequency function must _be_ an analytic function. However, in the presence of even _minimal_ noise, it fails. It's only useful in situations of almost unreal S/N ratios, and I have never heard of anyone considering it except theoretically. The Nyquist criterion still holds in the real world. To repeat a theme - be careful of what you are claiming for enhancement. It's easy to pull out almost anything you wish from a sufficiently complex object with appropriate filtering and enhancement. Just look at what people get out of Bible! Kevin Ryan Asst. Dir. Imaging Tech. Biological Sciences Carnegie Mellon U. kr0u@andrew.cmu.edu Disclaimer - These statements in no way reflect the policies/opinions of CMU, even though I'm right... ------------------------------ End of SPACE Digest V10 #54 *******************