IRIS processing script

[MarkS]

As you know, I have been using the free IRIS software for all my DSLR processing since day one.
IRIS users maybe interested in the script I currently use:

load dark
mult 1.0
add offset
save tempoffset
sub2 myimage tempoffset out 0 $1
div2 out flat outt 20000 $1
cosme_cfa2 outt out cosme $1
cfa2pic out outt $1
noffset2 outt out 250 $1
setfindstar 20
setregister 1
coregister2 out myimagereg $1

add_norm myimagereg $1
visu 1000 -200
save myimageaddnorm
composit myimagereg 1.5 1 1 $1
visu 1000 -200
save myimagecomp
composit myimagereg 1.5 1 0 $1
visu 1000 -200
save myimagecompnomax

To use it, save it as a file called "processmyimage.pgm" or whatever.  The "pgm" is important.
Run it from the IRIS command window by doing "run processmyimage 20" where 20 is the number of subs you have - obviously replace this by the actual number of subs you have.  As it runs, all the "$1" in the script will be replaced by 20.

A few comments:

1) The script assumes you have created "dark", "offset" and "flat" and that all your subs are saved in the processing folder as "myimage" - obviously change this to suit.  It also assumes you have a "cosme" file listing your hot pixels.  If you don't have one then create one ("find_hot" command) or remove the "cosme_cfa2" line.

2) The line "mult 1.0" can be changed to a different factor e.g "mult 0.5" to match your dark to your data.  I have a standard flat I created at 15C a couple of years ago.  For images taken at colder temperatures, I simply reduce the proportion of "dark" that I use.

3) The line "noffset2 outt out 250 $1" sets the median level of the image to 250.  It is important that all images have the same median before the later sigma stacking is performed.  Depending on your data, you may need to change this.  Experiment with 1 sub and adjust the level so you have no negative pixels in the image.  Negative pixels can upset the sigma stacking.

4) When the imaging is complete, "myimageaddnorm" gives a quick preview of the image.  The sigma stacked "myimagecompnomax" and "myimagecomp" can be combined into a single HDR (high dynamic range) in some other application if you first re-save them as TIFF files.  You may want to play with the "1.5" sigma parameter I use in the composit command.

5) This script is aimed at DSLR processing.  There are a few things you would need to change for processing monocrome images - i.e. change the "cosme_cfa2" to "cosme2" and remove the "cfa2pic" command.

Descriptions of the commands can all be found at Christian Buil's site:
http://www.astrosurf.com/buil/iris/nav_pane/CommandsFrame.html

Enjoy!

Mark

[JohnP]

All good stuff Mark however, all foreign to me

[The Thing]

Just what I need! I am stuck processing NGC3705B which was just NE of Mars on Saturday night (DSC). There are loads of little fuzzies around the area. When I stretch the image it gets dimmer and dimmer and I can't work out how to restore the contrast/brightness. I will try your script Mark!

[MarkS]

The script will give you a nicely stacked noise-free image.  Then the real work of processing begins and that really changes from image to image.

[The Thing]

The script will give you a nicely stacked noise-free image.  Then the real work of processing begins and that really changes from image to image.

Not on my PC it doesn't! Fiddling with the Sigma and Coefficient values (red was Min:-3684 on Stat output)...