IRIS to the rescue!

For those interested in imaging and image processing with DSLR, CCD, webcam or film.
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rwilkinson
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IRIS to the rescue!

#1 Post by rwilkinson » Thu Aug 09, 2012 12:49 pm

Last night I was testing a different combination of webcam, computer and software, and although everything looked OK on the screen at the time, when I came to look at the files this morning I found something very strange:
colourfault.jpg
all the Green & Blue fields were inverted in this entire sequence of images
colourfault.jpg (39.33 KiB) Viewed 3259 times
But a couple of hours after deleting these files, I thought of a way to recover them using IRIS.
So having restored them from the Recycle Bin I set about the rescue misson.
I loaded each file in turn, then split the Red, Green & Blue fields (as Gerald demonstrated the other evening), flipped the G & B and then re-merged them.
Using the IRIS Looper utility (http://www.wilmslowastro.com/software/d ... er_v04.zip) it was easy to run the following loop of instructions:
load image
split_rgb r g b
load g
mirrorx
save g
load b
mirrorx
save b
merge_rgb r g b
save image

on each of my 25 lights and 24 calibration frames - it only took a few minutes.

Then I was able to follow the usual processing work-flow to obtain this image:
m27_rescue.jpg
M27 planetary nebula, imaged before the sky was properly dark.
25x 30-sec, plus 12 each offset & dark calibration frames.
m27_rescue.jpg (25.56 KiB) Viewed 3259 times
So the morals of the story are:
  • don't throw away "useless" images - you may eventually discover a way to rescue them!
  • it's well worth the time spent learning to use the IRIS program
  • use the not-so-dark nights to practice with your camera, computer & software, so you'll have everything sussed in time for the winter...

Amartin

Re: IRIS to the rescue!

#2 Post by Amartin » Thu Aug 09, 2012 1:00 pm

Fantastic turnaround there Ross... A lesson for us all - never doubt the power of IRIS!

I think i'll have a dance with my 'awful M57' shots.

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