Gimp FITS violates FITS standard.

Gimp FITS violates FITS standard.

Post by Marc Pou » Thu, 11 Nov 1999 04:00:00



Newsgroups: comp.graphics.apps.gimp
Subject: Gimp FITS images violate FITS standard
Summary:
Expires:
Sender:
Followup-To:
Distribution:

Keywords:

The Flexible Image Transport System (FITS) is an image format
invented by and primarily used by astronomers.  One of the founding
principles of the format is that all records must be 2880 bytes long.
(2880 is divisible by both the byte and word lengths of all computers
available at the time the standard was proposed: 6,8,12,16,18,24,32,36,48,60 and 64.)
Thus a file size should be divisible by 2880.  I just saved a JPG as
FITS using gimp 1.1.9 and the file size is 1175580 bytes.  This violates
the FITS standard! Granted, most FITS readers will let this slip by
with no ill-effects. But, the data should be padded with zeroes to
fill out the record.

The original paper describing FITS may be found at:

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1981A%26AS......

More current information on the FITS standard may be found at:
http://www.gsfc.nasa.gov/astro/fits/fits_home.html and http://www.cv.nrao.edu/fits

Marc Pound
Astronomy Dept
University of Maryland, College Park

 
 
 

1. Gimp FITS images violate FITS standard

The Flexible Image Transport System (FITS) is an image format
invented by and primarily used by astronomers.  One of the founding
principles of the format is that all records must be 2880 bytes long.
(2880 is divisible by both the byte and word lengths of all computers
available at the time the standard was proposed: 6,8,12,16,18,24,32,36,48,60 and 64.)
Thus a file size should be divisible by 2880.  I just saved a JPG as
FITS using gimp 1.1.9 and the file size is 1175580 bytes.  This violates
the FITS standard! Granted, most FITS readers will let this slip by
with no ill-effects. But, the data should be padded with zeroes to
fill out the record.

The original paper describing FITS may be found at:

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1981A%26AS......

More current information on the FITS standard may be found at:
http://www.gsfc.nasa.gov/astro/fits/fits_home.html and http://www.cv.nrao.edu/fits

Marc Pound
Astronomy Dept
University of Maryland, College Park

2. Graphics schools in the UK

3. Beizer curve fitting/ B-spline Fitting

4. Cross Platform Sound API?

5. weighted fitting - standard deviation vs. variance

6. 8 bit BMP to 8 bit JPEG

7. Fitting text to a curve // GIMP 1.1.25

8. Video overlay card

9. PNG standard may violate patent!

10. How to fit selected data from a datafile and draw all the data and fit function together?

11. Problem with "undefined fit parameters" in gnuplot 3.6 (ML-fit)

12. stretching textures to fit polygonal models

13. FITS->BMP