Splitting BMPs

[andyschlei]

This is my first post and I am afraid it is a bleg.

Iceman posted (http://www.bautforum.com/showthread.php?t=41188) some excellent Jupiter photos at the Bad Astronomy/Universe Today forum (http://www.bautforum.com/), and followed up with great advice on processing.

I am stuck on the step of splitting the BMPs from the AVI into separate R/G/B images. I took an admittedly quick view through the archives here and did not find the gem of knowledge on how to do this.

I apologize in advance if this is an easy question, and thank everyone (also in advance) for any help on this.

--Andy
Observatorio de la Ballona (http://obsballona.net/)

[davidpretorius]

gday mate, where the bloody hell are ya!!!

enough aussie lingo.

i use aviraw to split my avi into separate colour r,g,b. from there I convert those separate r.g.b avis into bmps with bink and smacker. virtual dub would work too.

ppmcentre then crops and centres the bmps and does a pre quality sort if needed.

then into registax.

Mike (Iceman) has a script setup where he converts first from avi to bmps via virtual dub and then runs the script to convert bmps into split colours and then also run ppmcente.

My dos is not great, so i have not had a chance to do the same thing via scripts.

aviraw is the first step i would think. The only quirk is that the program needs you to convert to a rgb first or convert a raw in to a rgb first before trying to split the avi's into colours.

http://arnholm.org/astro/software/aviraw/

come back and ask any questions at any time, the lights are always on in australia, the country that never sleeps!

[[1ponders]]

Welcome Andy. Slitting can be done a couple of ways.

If you are going to split your inital Avi then use Aviraw to do that. If you are going to split a final image after running through Registax then use Astro image to so that.


There are a couple of discussions going on atm I see if I can dig them up

The main discussion of splitting is going on here (http://www.iceinspace.com.au/forum/showthread.php?t=9669) atm

[[1ponders]]

Damn that DPs quick :P

[davidpretorius]

welcome by the way,

nice website you have got running there and great observatory setup!

well done

[andyschlei]

Thanks for the quick responses. I'm looking forward to trying the software out tonight.

And thanks DP for the kind comments about my site.

[andyschlei]

Well I have all of the software in place. I have used virtual dub to split the avi into individual BMPs, and am trying to process them with ppmcentre. However, I got the following error:



To fix it, I set the threshold to 65 (after looking at the image in PS). I took me a while to understand the error message, but I finally got it.

I am on the second pass through the bmps with ppmcentre as I forgot the -qestimator and -renumber on the first pass.

[iceman]

Nice work Andy..

That threshhold parameter is needed if the image is inherintly grainy from high gain (in poor transparency).

The command line I use for ppmcentre (in a script called "image_ppm_script.sh" is:

#!/bin/sh

image_dir=$1

./ppmcentre -width=400 -height=400 -cutx=400 -cuty=400 -overwrite -inputfilter -qestimator -renumber $image_dir


I run mine through a unix emulator "cygwin" on Windows.

So if I've got several bmp directories, eg:
images/jup1bmp
images/jup2bmp
images/jup3bmp

I run the command:


for i in `ls -d images/jup*bmp`
do
./image_ppm_script.sh $i
done;


That runs the ppmcentre command through all bmp directories one after the other. So I can kick it off before I go to bed and it's done when I wake up in the morning :)

[andyschlei]

One last note before I call it a night. It seems that Registax has a limit on the number of BMPs that it can handle. There is no message, but I was able to load 200, but not 300 BMPs for processing.

Does anyone know of a hard limit?

[andyschlei]

I was processing an image at f40, so the gain was very high. I've got a fair amount of light pollution, and as I recall the transparency wasn't great either, so there was a lot of background noise.

In my searches for programs to split files, I came across a Linux program that will break an AVI into BMPs in batch. It is called mplayer. I might run under cygwin and help you to extend what can be done in batch mode.

I am trying a parallel path for processing on my Linux machines, we'll see how it goes. I will try to get XP to work first.

Thanks for the help.

--Andy

[iceman]

Don't use "open" - instead, drag'n'drop the BMP's into registax. Then you can drag thousands in there.

[iceman]

yeh if I could batch up the splitting of avi's into BMP's, that'd be great - cause that manual step in VirtualDub is quite frustrating.

I usually do it while capturing avi's.. that is, after i've finished capturing one avi, i'll open it in virtual dub and start saving the BMP's. I've found that I can still capture the next avi while VirtualDub is saving the previous as BMP's.

The only problem with batching that step, is that sometimes the planet runs off the frame slightly during part of the AVI because my tracking isn't very good. I use virtualdub to delete those bad frames where part of the planet is outside the FOV, so registax doesn't think it's "sharp". To be able to batch it, I'd need to much more careful about keeping the planet in the FOV during the whole capture.

[andyschlei]

Thanks!