iraf.net

This may be covered somewhere, but being a IRAF newbie, I cannot find the right "AH HA!" bit of documentation.First a bit of background, I'm just getting into astrophotography, and am using a Canon 20Da digital camera for imaging. I'm using the RAW image format for capturing the images. The data is 12-bits per pixel. The stumper is that I am running Linux (what's Windows?), and while there are quite a few conversion programs available that can handle the display depth, I am having difficulty finding a package that can do the actual image processing itself (such as registration of images, and general image processing) with the display depth. The most popular Linux image processing package, GIMP, is restricted to 8-bit channels. So.. this leads me to IRAF. I do see that IRAF is quite complicated, and that part doesn't really "scare" me -- I've dealt with computers long enough that having to do real programming and command lines are more friendly to me then windowing systems I have IRAF installed, and kind of understand how it works, but as I stated above, I just need the right bit of "AH HA". So.. the question is, what would the workflow look like for say processing two images that need to be aligned and then combined in IRAF.(oh.. I have DS9 installed and working as well)Here is what I would assume..Use DCRAW to convert the Canon 20Da raw image file into PPM format. There are several output options, but basically the result is a 16-bit per pel image.The next steps are the ones I really have questions on..
Convert to FITS?
load image into IRAF -- but this is where I start having problems in that it doesn't seem
to be able to handle the color information correctly.Anyway -- thanks in advance for any assistance. I'm hoping that this is the "correct" path.

---

Cheyenne Wills

The IMPORT/EXPORT tasks in the DATAIO package are able to convert the PPM file to FITS (import) and then back out to something like a GIF (export) that GIMP could handle. Note however that FITS doesn't have a color model and so you may need to deal with the RGB planes of the image separately. You're images are also likely missing a WCS in the header so you'll be dealing mostly with pixel coordinates. You can use the REFERENCES task (or the 'Apropos' search bar above) to look around for tasks that might help 'register' or 'shift' your images by various means. If you goal is to combine the images into a color format at the end, using IRAF for the registration and GIMP for the combination isn't a bad way to go. There are a number of Windows-based applications for astrophotography that might be easier, using VMware to run them in a windows virtual machine is another option.Lastly, see the registration document at https://iraf.net/irafdocs/reg/Hope this helps.-Mike