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Philip Massey wrote on Mar 09, 2019

Hi Mike et al---

I've come across about dozen ancient IRAF images (IIDS data) that are still in the "imh" and "pixels" form. The weird thing is that although I can see them find with an ls, imhead says it can't open the file. I could understand it if the pixel path was screwy, and I still remember how to fix that, but I can't access the header. The images are from 1983 or earlier, so we are talking very early IRAF days.

My guess is that the bytes are swapped. I don't really have access to a SUN (maybe a VMS?) machine any more. Any suggestions about how to unswap these? This is not mission critical; I was just thinking it would be useful to show this during a talk I'm giving; there's a spectrum of a star we called a Wolf-Rayet star that turns out to be a z=2.5 quasar, and I thought showing the original crummy data would help explain how we could have fooled ourselves.

Thanks!

--phil

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Mike Fitzpatrick wrote on Mar 11, 2019

Hi Phil,

Could you email me a sample imh and .pix file -- It's probably a byte-swap issue but it makes a difference whether it was originally a VMS file or some unix variant. Reconnecting the .pix to the header is a matter of changing the i_pixfile header field to change the path, but you need to be able to open the image with HEDIT or something first.....

Cheers,

-Mike

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Last post on Mar 11, 2019