From rlm@astro.physics.uiowa.edu Mon Jan 3 11:54:12 1994 X-VM-VHeader: ("Resent-" "From:" "Sender:" "To:" "Apparently-To:" "Cc:" "Subject:" "Date:") nil X-VM-Bookmark: 3 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1527" "Mon" "3" "January" "1994" "14:46:26" "GMT" "Robert Mutel" "rlm@astro.physics.uiowa.edu" nil "34" "Re: ST-6 Image: FITS format" "^From:" nil nil "1" nil nil]) Status: RO Newsgroups: sci.astro Path: cv3.cv.nrao.edu!hearst.acc.Virginia.EDU!darwin.sura.net!howland.reston.ans.net!vixen.cso.uiuc.edu!newsrelay.iastate.edu!hobbes.physics.uiowa.edu!sunlight!rlm Message-ID: Nntp-Posting-Host: sunlight.physics.uiowa.edu Reply-To: rlm@astro.physics.uiowa.edu Organization: University of Iowa References: <2fvs2u$ck2@canopus.cc.umanitoba.ca> Lines: 34 From: rlm@astro.physics.uiowa.edu (Robert Mutel) Sender: news@space.physics.uiowa.edu Subject: Re: ST-6 Image: FITS format Date: Mon, 3 Jan 1994 14:46:26 GMT In article ck2@canopus.cc.umanitoba.ca, youngs@cc.umanitoba.ca (Scott D. Young) writes: > > Just a note to anyone who is using the ST-6 software: it does NOT support > the FITS format. Yes, I know there is an option to save a file as a "FITS" > but it does not work. They write the file incorrectly; something about > flipping the high-order bit or something (I'm not sure of the details). > We have a program to convert SBIG files to FITS files; it is easy enough > to do if you have the FITS format information (see sci.data.formats). > > Scott Young > youngs@ccu.umanitoba.ca This is not quite correct. The exported FITS format of ST-6 images is fine except for an ambiguity with [all] 16-bit integer FITS files, viz that the most significant bit (MSB) is either treated as a sign bit or a magnitude bit. The ST-6 uses the MSB as a mag. bit, so that FITS readers which treat it as a sign bit will 'fold' all intensities i>32767 to -65536+i. [I believe the keyword BIXPIX=SIMPLE is supposed to sort this out, but a FITS expert can comment.] We have both ST-6 and HPC-1 cameras, both of which use the MSB as a magnitude bit. Our FITS image readers (e.g. Imagine-32 ,SAOimage, AIPS) assume MSB is a sign bit. The work-around is to convert to floating point format and add 32767 to all images. Robert Mutel Department of Physics and Astronomy University of Iowa Iowa City IA 52242 Telephone: 319-335-1950 FAX: 319-335-1753 Email: rlm@sunlight.physics.uiowa.edu (internet) iowa::rlm (span) From hanisch@stsci.edu Mon Jan 3 13:36:13 1994 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2315" "Mon" "3" "January" "1994" "17:38:03" "GMT" "Bob Hanisch, ST ScI" "hanisch@stsci.edu" nil "50" "Re: ST-6 Image: FITS format" "^From:" nil nil "1" nil nil]) Status: RO Newsgroups: sci.astro Path: cv3.cv.nrao.edu!hearst.acc.Virginia.EDU!darwin.sura.net!paladin.american.edu!europa.eng.gtefsd.com!uunet!organpipe.uug.arizona.edu!CS.Arizona.EDU!noao!stsci!iris.stsci.edu!hanisch Message-ID: <1994Jan3.173803.15823@stsci.edu> Reply-To: hanisch@stsci.edu Organization: Space Telescope Science Institute, Baltimore MD References: Lines: 50 From: hanisch@stsci.edu (Bob Hanisch, ST ScI) Sender: news@stsci.edu Subject: Re: ST-6 Image: FITS format Date: Mon, 3 Jan 1994 17:38:03 GMT In article B5I@space.physics.uiowa.edu, rlm@astro.physics.uiowa.edu (Robert Mutel) writes: >In article ck2@canopus.cc.umanitoba.ca, youngs@cc.umanitoba.ca (Scott D. Young) writes: >> >> Just a note to anyone who is using the ST-6 software: it does NOT support >> the FITS format. Yes, I know there is an option to save a file as a "FITS" >> but it does not work. They write the file incorrectly; something about >> flipping the high-order bit or something (I'm not sure of the details). >> We have a program to convert SBIG files to FITS files; it is easy enough >> to do if you have the FITS format information (see sci.data.formats). >> >> Scott Young >> youngs@ccu.umanitoba.ca > >This is not quite correct. The exported FITS format of ST-6 images is >fine except for an ambiguity with [all] 16-bit integer FITS files, viz >that the most significant bit (MSB) is either treated as a sign bit or >a magnitude bit. The ST-6 uses the MSB as a mag. bit, so that FITS >readers which treat it as a sign bit will 'fold' all intensities >i>32767 to -65536+i. [I believe the keyword BIXPIX=SIMPLE is supposed >to sort this out, but a FITS expert can comment.] We have both ST-6 and >HPC-1 cameras, both of which use the MSB as a magnitude bit. Our FITS >image readers (e.g. Imagine-32 ,SAOimage, AIPS) assume MSB is a sign >bit. The work-around is to convert to floating point format and add >32767 to all images. > > >Robert Mutel >Department of Physics and Astronomy >University of Iowa >Iowa City IA 52242 > >Telephone: 319-335-1950 FAX: 319-335-1753 >Email: rlm@sunlight.physics.uiowa.edu (internet) > iowa::rlm (span) > The FITS standard for 16-bit integer data is for it to be twos-complement, signed integers. Unsigned 16-bit integers are not FITS compliant, i.e., are inconsistent with SIMPLE = T. In principle you could write unsigned 16-bit integers with SIMPLE = F, but there is no guarantee that a FITS reader will be able to interpret your data properly then. Bob Hanisch --- Robert J. Hanisch Tel. (410)338-4910 Fax. (410)338-5090 Space Telescope Science Institute NSI: hanisch@stsci.edu [130.167.1.2] 3700 San Martin Drive DECNet: STSCIC::HANISCH [6549::] Baltimore, MD 21218 USA Bitnet: hanisch@stsci From dwells@fits.cv.nrao.edu Mon Jan 3 13:55:33 1994 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2090" "Mon" "3" "January" "1994" "18:33:17" "GMT" "Don Wells" "dwells@fits.cv.nrao.edu" nil "43" "Re: ST-6 Image: FITS format" "^From:" nil nil "1" nil nil]) Status: RO Xref: cv3.cv.nrao.edu sci.astro:35072 sci.astro.fits:572 Newsgroups: sci.astro,sci.astro.fits Path: cv3.cv.nrao.edu!cv3.cv.nrao.edu!dwells In-Reply-To: rlm@astro.physics.uiowa.edu's message of Mon, 3 Jan 1994 14: 46:26 GMT Message-ID: Organization: nrao References: <2fvs2u$ck2@canopus.cc.umanitoba.ca> Lines: 43 From: dwells@fits.cv.nrao.edu (Don Wells) Sender: news@nrao.edu Subject: Re: ST-6 Image: FITS format Date: Mon, 3 Jan 1994 18:33:17 GMT [I have added sci.astro.fits to the Newsgroups line -DCW] In article rlm@astro.physics.uiowa.edu (Robert Mutel) writes: RM> .. an ambiguity with [all] 16-bit integer FITS files, viz that RM> the most significant bit (MSB) is either treated as a sign bit RM> or a magnitude bit. .. There is no ambiguity in the definition of FITS for BITPIX=16: FITS readers should always construe 16-bit pixels as 2-s complement signed integers. FITS readers should also obey the BSCALE and BZERO keywords when they are present (and should default to BSCALE=1 and BZERO=0 when they are absent). The formula which FITS readers should use to interpret FITS pixels is physical_value = BZERO + BSCALE * array_value (See Eq.5.3 in Sect.5.2.2.5 on p.19 of the NOST 100-1.0 version of the FITS standard, or item III.D.1 on p.368 of the Basic FITS paper in June 1981 A&A supplement Series, or Eq.3.2 in Sect.3.1.1.2 of the NOST FITS User's Guide). RM> The ST-6 uses the MSB as a mag. bit, so that FITS readers which RM> treat it as a sign bit will 'fold' all intensities i>32767 to RM> -65536+i. .. We have both ST-6 and HPC-1 cameras, both of which RM> use the MSB as a magnitude bit. .. 16-bit A-to-D converters produce unsigned integers; unsigned integers are not supported by FITS. When these pixels are being written to FITS files with BITPIX=16 the camera software can utilize the optional BZERO FITS keyword to shift the zero point of the number system in order to give a 16-bit positive range instead of the default positive and negative 15-bit range. The camera software should subtract 32768 >from the pixels (or, equivalently, add 8000_hex) and set BZERO=32768 and BSCALE=1 in the header. If this is done, properly coded FITS readers will construe the pixels correctly. -- Donald C. Wells Associate Scientist dwells@nrao.edu http://fits.cv.nrao.edu/~dwells National Radio Astronomy Observatory +1-804-296-0277 520 Edgemont Road, Charlottesville, Virginia 22903-2475 USA From R.DELOACH@larc.nasa.gov Sun Jan 23 08:03:12 1994 Path: saips.cv.nrao.edu!hearst.acc.Virginia.EDU!caen!usenet.cis.ufl.edu!eng.ufl.edu!saimiri.primate.wisc.edu!sdd.hp.com!sgiblab!swrinde!cs.utexas.edu!howland.reston.ans.net!usenet.ins.cwru.edu!lerc.nasa.gov!news.larc.nasa.gov!eigen.larc.nasa.gov!R.DELOACH From: R.DELOACH@larc.nasa.gov (Dick DeLoach) Newsgroups: sci.astro Subject: Re: Hubble FITS location/availability? Date: Fri, 21 Jan 1994 13:16:47 Organization: NASA Langley Research Center Lines: 16 Distribution: usa Message-ID: References: <2h7hr4$1dkc@bigblue.oit.unc.edu> <2hmogv$gcv@news.cerf.net> NNTP-Posting-Host: eigen.larc.nasa.gov X-Newsreader: Trumpet for Windows [Version 1.0 Rev A] In article <2hmogv$gcv@news.cerf.net> sikes@nic.cerf.net (Terry Sikes) writes: >From: sikes@nic.cerf.net (Terry Sikes) >Subject: Re: Hubble FITS location/availability? >Date: 20 Jan 1994 20:11:11 GMT >On a related note, where is the FITS file format documented? The formal ftp format specification can be found in the libraries of the CompuServe graphics support forum ("GO GRAPHICS" to access from any CompuServe prompt.) It no doubt exists elsewhere but this is the only place I've seen it myself. --- Dick From nrt@mail.ast.cam.ac.uk Mon Jan 24 15:18:45 1994 Newsgroups: sci.astro Path: saips.cv.nrao.edu!hearst.acc.Virginia.EDU!concert!news-feed-2.peachnet.edu!darwin.sura.net!haven.umd.edu!news.umbc.edu!europa.eng.gtefsd.com!howland.reston.ans.net!pipex!pavo.csi.cam.ac.uk!news From: nrt@mail.ast.cam.ac.uk (Nial Tanvir) Subject: Re: FITS/GIF Message-ID: <1994Jan24.171528.483@infodev.cam.ac.uk> Sender: news@infodev.cam.ac.uk (USENET news) Nntp-Posting-Host: coral.ast.cam.ac.uk Reply-To: nrt@mail.ast.cam.ac.uk Organization: Institute of Astronomy, Cambridge References: <2hv987$jk8@enzu.unm.edu> Date: Mon, 24 Jan 1994 17:15:28 GMT Lines: 16 You can use XV, but you need some patches to allow it to read and write FITS. You need XV version 3.00a (can be obtained from ftp.cis.upenn.edu in /pub/xv), the patches were written by David Robinson here and can be obtained from our anonymous ftp server which is called ftp-hst.ast.cam.ac.uk Look in directory /pub/software/xv-patches. Hope this helps (don't know of any way using IRAF), Nial Tanvir. ------============----- HST UK Support Facility -----==========---- From fitz@noao.edu Mon Jan 24 18:14:36 1994 Newsgroups: sci.astro Path: saips.cv.nrao.edu!hearst.acc.Virginia.EDU!darwin.sura.net!paladin.american.edu!howland.reston.ans.net!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!newncar!noao!fitz From: fitz@noao.edu (Mike Fitzpatrick) Subject: Re: FITS/GIF Message-ID: <1994Jan24.203316.3111@noao.edu> Originator: fitz@pisces.tuc.noao.edu Sender: news@noao.edu Nntp-Posting-Host: pisces.tuc.noao.edu Organization: National Optical Astronomy Observatories, Tucson, AZ, USA References: <1994Jan24.171528.483@infodev.cam.ac.uk> Date: Mon, 24 Jan 1994 20:33:16 GMT Lines: 15 There currently isn't any way to do this directly in IRAF, although we may provide this capability in the future. Another solution would be to get Jef Poskanzer's pbmplus package (from ftp.ee.lbl.gov, ucsd.edu, ftp.x.org among others) and use a recipe such as % cat foo.fits | fitstopgm | pgmtoppm | ppmtogif > foo.gif It *is* possible to get Sun rasterfiles out of IRAF and convert from there, but using XV or the above is easier (for now). IRAF questions can be sent directly to iraf@noao.edu, we normally don't monitor sci.astro. I hope this helps. Mike Fitzpatrick NOAO/IRAF Group fitz@noao.edu From keel@hera.astr.ua.edu Tue Jan 25 12:11:19 1994 Newsgroups: sci.astro Path: saips.cv.nrao.edu!hearst.acc.Virginia.EDU!caen!sol.ctr.columbia.edu!howland.reston.ans.net!darwin.sura.net!ua1ix!hera.astr.ua.edu!keel From: keel@hera.astr.ua.edu (&) Subject: Re: FITS/GIF Message-ID: <1994Jan25.150456.115773@ua1ix.ua.edu> Sender: news@ua1ix.ua.edu Nntp-Posting-Host: hera.astr.ua.edu Organization: The University of Alabama X-Newsreader: TIN [version 1.1 PL8] References: <2hv987$jk8@enzu.unm.edu> Date: Tue, 25 Jan 1994 15:04:56 GMT Lines: 25 heli fairweather (helix@unm.edu) wrote: : Does anyone know how to make a FITS image into a gif? preferable using IRAF. If there's a Silicon Graphics machine available, what I do is: display from IRAF into SAOImage or a similar display window capture this into an SGI-format image using the imgsnap utility convert into GIF using the SGI togif program. You can even composite three monochrome images into color by doing it for each of the individual frames as far as SGI format, then using tobw to make each RGB frame B&W and applying cglue to paste them together (some examples can be found on crux.astr.ua.edu in the web and pub/outgoing/hstgifs directories). I am told (but cannot personally verify) that functionally similar routines are available for Sun machines. -------------------------------------------------------------------------- Bill Keel Astronomy, University of Alabama keel@bildad.astr.ua.edu (that's Tuscaloosa) I am professionally bound to deal with only those dimwits who 1) wrote a proposal I'm reviewing, 2) wrote a paper I'm refereeing, or 3) are currently faculty, staff, or students at the University of Alabama. Others will be dealt with as my need for amusement allows. From tim@zeno.as.arizona.edu Tue Jan 25 17:15:01 1994 Path: saips.cv.nrao.edu!hearst.acc.Virginia.EDU!caen!malgudi.oar.net!news.ans.net!howland.reston.ans.net!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!newncar!noao!CS.Arizona.EDU!organpipe.uug.arizona.edu!zeno.as.arizona.edu!tim From: tim@zeno.as.arizona.edu (Tim Pickering) Newsgroups: sci.astro Subject: Re: FITS/GIF Date: 25 Jan 1994 17:37:18 GMT Organization: University of Arizona UNIX Users Group Lines: 7 Distribution: na Message-ID: <2i3lce$m3n@organpipe.uug.arizona.edu> References: <1994Jan24.171528.483@infodev.cam.ac.uk> <1994Jan24.203316.3111@noao.edu> NNTP-Posting-Host: zeno.as.arizona.edu A kludgy way to do it is to display the FITS or IRAF image file with SAOimage and then use xv to "grab" the image. xv can then save the grabbed image to .gif or whatever format. I use it to make postscript output without the stupid SAOimage headers and buttons. I don't notice any reduction in quality. Tim From adam@csi.jpl.nasa.gov Tue Jan 25 23:52:07 1994 Path: saips.cv.nrao.edu!hearst.acc.Virginia.EDU!concert!news-feed-1.peachnet.edu!oldnews2.cis.umn.edu!zip.eecs.umich.edu!yeshua.marcam.com!news.kei.com!sol.ctr.columbia.edu!usc!elroy.jpl.nasa.gov!netline-fddi.jpl.nasa.gov!grover.jpl.nasa.gov!csi.jpl.nasa.gov!adam From: adam@csi.jpl.nasa.gov (Adam Bernstein) Newsgroups: sci.astro Subject: Re: FITS/GIF Date: 26 Jan 1994 01:42:44 GMT Organization: Jet Propulsion Laboratory Lines: 30 Distribution: na Message-ID: <2i4hqk$g12@grover.jpl.nasa.gov> References: <1994Jan24.171528.483@infodev.cam.ac.uk> <1994Jan24.203316.3111@noao.edu> <2i3lce$m3n@organpipe.uug.arizona.edu> NNTP-Posting-Host: bloodhound.jpl.nasa.gov In article <2i3lce$m3n@organpipe.uug.arizona.edu>, tim@zeno.as.arizona.edu (Tim Pickering) writes: |> A kludgy way to do it is to display the FITS or IRAF image file with |> SAOimage and then use xv to "grab" the image. xv can then save the |> grabbed image to .gif or whatever format. [...etc] Actually, xv can be modified to read FITS directly, at which point you can save it in any one of the other available formats. In the unsupported routines that come with the xv package (in the directory 'unsupt') are a few FITS read/write routines that can be built into the package, with instructions on how to do it. Unfortunately, the instructions are not exactly right, and the routines include some variables that have changed names from one version of xv to the next, so it'll take you a few hours; or if you want, I could send you a copy of the correctly modified routines. What's more, in order to be able to non-interactively convert a list of FITS images into GIF format, I adapted the xv code to create a routine that would do just that and nothing else. If anyone wants a copy of that, let me know and I'll send it along. Adam ------------------------------------------------------------------------ Adam Bernstein Phone: 818 354-9784 Jet Propulsion Lab Guidance & Control / FAX: 818 393-6105 MS 198-235 Optical Tracking Group 4800 Oak Grove Dr. adam@bloodhound.jpl.nasa.gov Pasadena, CA 91109 ------------------------------------------------------------------------ From roland@sics.se Wed Jan 26 10:59:10 1994 Newsgroups: sci.astro Path: saips.cv.nrao.edu!hearst.acc.Virginia.EDU!concert!gatech!howland.reston.ans.net!cs.utexas.edu!convex!cnn.exu.ericsson.se!ericom!sics.se!roland From: roland@sics.se (Roland Karlsson) Subject: Re: FITS/GIF In-Reply-To: adam@csi.jpl.nasa.gov's message of 26 Jan 1994 01:42:44 GMT Message-ID: Lines: 14 Sender: news@sics.se Organization: Swedish Institute of Computer Science, Kista References: <1994Jan24.171528.483@infodev.cam.ac.uk> <1994Jan24.203316.3111@noao.edu> <2i3lce$m3n@organpipe.uug.arizona.edu> <2i4hqk$g12@grover.jpl.nasa.gov> Distribution: na Date: Wed, 26 Jan 1994 07:35:24 GMT The PBMPLUS package contains a FITS to PGM (portable gray map) converter called fitstopgm. This format can then be converted to almost any format you can imagine. You can even combine three RGB PGM files to one color PPM (portable pix map) file. From this file you can generate GIF or JPEG or whatever. xv knows both the PGM and the PPM format. -- Roland Karlsson SICS, PO Box 1263, S-164 28 KISTA, SWEDEN Internet: roland@sics.se Tel: +46 8 752 15 40 Fax: +46 8 751 72 30 Telex: 812 6154 7011 SICS Ttx: 2401-812 6154 7011=SICS