Legacy ImageMagick Discussions Archive

Can anybody show me how to do anything at all with FITS files? Convert and Display treat my files as being completely black.

Here is one of the files I am working with:

http://jjfoerch.com/bitbucket/pluto_1.fts

Here is what it should look like like... I made this image by converting with gcx.

http://jjfoerch.com/bitbucket/pluto_1.png

I am interested in knowing any and all techniques other ImageMagick users are using to work with astronomical images.

Thank you!

(ImageMagick 6.3.0 on Debian)

Your FITS image incorrectly sets the DATAMAX to 65535 so ImageMagick does not search for the true min and max value. We fixed this problem in ImageMagick 6.3.0-2 Beta (available by tommorrow) such that the DATAMAX statement is ignored unless accompied with a DATAMIN statement.

Actually this file is 16 bit unsigned fits file, so that DATAMAX header is correct. I found the following link that explains how unsigned data types are supported by FITS.

http://heasarc.gsfc.nasa.gov/docs/softw ... ode22.html

So ImageMagick should look at the BSCALE and BZERO headers to determine the signedness of the data.

Here is a link to the DATAMAX entry in the FITS Standard.

http://archive.stsci.edu/fits/fits_stan ... 0.html#876

It is defined as a float giving the maximum valid physical value represented by the array. So 65535 is correct for my file.