Load multi extension tile compressed fits report error. about js9 HOT 9 CLOSED

Can you attach or send a FITS file? I'll be happy to look at it.

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20200326_7906_906176_0008.zip
Here is the fits file. I can open it with ds9 or astropy correctly.

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@fockez Using that test file, the cfitsio library gets an error in fits_convert_hdr2str(), both in js9 and in non-js9 programs. There is special code in fits_convert_hdr2str() to deal with compressed images, so my first guess was that there is a header parameter that is tripping up cfitsio, especially since I routinely load rice-compressed images in other test files.

And indeed, after messing around with the file, the problem seems to be with the 2 parameters BSCALE and BZERO that come after TFIELDS and before TTYPE1. If I delete them from the file, js9 and non-js9 programs work fine:

So I think the options are to move those parameters (I didn't try this but I assume moving them down in the header will help) or else we can submit a bug report to cfitsio. fverify does not complain about these params or their location, so this really might a problem with cfitsio itself.

Let me know how you want to proceed.

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Thanks for your work on that. I think for now, if move header keyword position would help, that's simple enough, right?

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Yes, if you have control over the order in which the keywords are written, I'd move the BSCALE and BZERO params to some place after the Z params. I did that and was able to load the FITS file.

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@fockez Were you able to move the BSCALE and BZERO parameters and then use JS9 to display the file? The cfitsio team would especially like to know ... if you have worked around the problem in that way, they can put it into a less urgent queue for fixing.

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Yes, if I adjust all the extensions' header order, it can be read by js9. Thanks. @ericmandel

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I'll close this, then, but will update it if cfitsio gets fixed.

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