ppmcentre.exe

[asimov]

This program was written by bird on put on this forum for anyone to use. I downloaded it & tried it but when I open the program, all I get is a real quick look at at black box with text. (like an ms-dos prog.) Then it flashes off the screen. I have 98se. Anyone else tried this program? & if so, does it work for you?? ppmcentre.exe (http://www.iceinspace.com.au/download.php?2352e8276bbf6324b8426e c0313b96f9)

[davidpretorius]

having troubles remembering 98se, but open up a dos session and then change directory to where ppmcentre.exe is located.

cd\c:\astronomy etc

ppmcentre /? will then bring up what it does

by the look of it

you put a bunch of images in .bmp into a directory and then ppmcentre c:\mynewphotos and all images in that directory will be aligned

i will try now with some of my drift by shots

[asimov]

http://www.iceinspace.com.au/forum/showthread.php?t=587 Iv'e tried all the info in this thread. The only option I have here is to re-start in dos mode....which I wont be doing. Goodbye lil' ppm centre....it's off to the recycle bin we go...hehehe!

[davidpretorius]

yes, not a bad idea. do you need ppmcentre if you have tracking?

[asimov]

Nah. Theres plenty of other ways to get an object in the centre of a frame. I've got 1/2 dozen proggy's that do it for you. micrografx picture publisher is usually the one I use most..I'm not even sure if I need to do this even though I have tracking. My tracking isn't too good. I just plonk the EQ out in the back-yard, with a rough polar alignment, & adjust the DEC axis as I'm shooting to keep the object central in the LCD screen. Obviously if I was doing long exposures, this wouldn't work! Bright planets are fine though..

[iceman]

Surely win98se can bring up a dos prompt?

What I do:
1. My avi's are located in \capture\images (for example)
2. ppmcentre is located in \capture
3. I create sub directories for the set of bmp's for each avi. eg: \capture\images\jup1bmp, \capture\images\jup2bmp
4. I use virtualdub to save the avi as a set of bmp's into each subdirectory. Before saving, I delete the obviously bad frames that were out of the FOV or blurry due to bad seeing or scope movement.
5. Go to dos prompt
6. cd \capture
7. ppmcentre -width=400 -height=400 images\jup1bmp
8. repeat for the other bmp directories

The benefit of using ppmcentre, even if your tracking is fairly accurate, is that it can speed up processing time in registax because each frame is only 400x400 (instead of 640x480) so it processes them quicker. It also seems to align quicker with the object in the centre of each frame. Obviously 400x400 is fine for the planets where they are normally smaller than that. Those with large image scales might need to adjust.
Also when doing the moon, I skip this ppmcentre step completely as it doesn't make sense.

9. Open registax
10. Using windows explorer, drag the set of bmp's into registax

HTH