iraf.net

Hi Mike et al.,
I am trying to use imedit on pretty crowded and confused images (in my case regions in emission-line images from which I have subtracted a continuum image to remove the stars and keep the nebulosity alone). Often there's a star that is imperfectly subtracted quite close to some bit of filamentary nebulosity. What I want to do is go in and "repair" the image--get rid of that offending remnant star. The usual "b" aperture replacement command doesn't work well here because the background annulus will sample the filament and so give a substitution value that is both too high and too noisy. What I want to do instead is to "grab" a bit of nearby blank sky and use that to replace the offending star--with no added background. The "m" command allows me to copy some sky to a buffer, and then a second "m" seems to place that where I want it, BUT some local background is added. I just want to disable looking at the local background and copy the buffer contents in unmodified. I'm almost certain I've known how to do it in the past, but I've now read the help pages several times, and have tried lots of experiments--yet remain stymied. If you can tell me how to do it, I'd really appreciate it.
Thanks!
Paco=Frank Winkler

Hi Frank,I'm not completely sure if I understand. I think you are saying you don't want any background fitting to be done when you select a region to copy and when you paste the copy into the new location.I'm sorry but it appears that you cannot defeat the background subtraction in imedit. The alternative is to use imcopy with an image section:[code:1:51f725a0a7]
imcopy original new
imcopy original[123:133,456:466] new[153:163,473:483]
[/code:1:51f725a0a7]Let me know if I didn't understand what you want to do.Yours,
Frank

Yep, I believe you have this right. I'm hoping to "defeat" the background subtraction feature--simply copy what looks like blank sky from one place, and paste it in somewhere else. Otherwise, I'm not sure what the purpose of the "m" command is. I know I could do this using imcopy on a section, but that is pretty darn tedious! Also only allows rectangular sections.If I can't do what I really want in imedit, maybe setting the background fitting orders to 0 will at least minimize the problem.Thanks,
Paco