[ptx] Re: Hugin for OS X problems

[Ian Wood]

On 5 Nov 2005, at 12:00, Carl von Einem wrote:

>> Since you are just getting started you should probably be working  
>> with smaller
>> images at this time.  There is a significant learning curve to  
>> using these
>> tools and when working with very large stitches you magnify that  
>> learning
>> curve.  A 12 image stitch should probably wait until you have a  
>> least a
>> handful of smaller stitches under your belt.  Go in the back yard  
>> or down the
>> street and shot some 3 or 4 image panos to help learn more about  
>> the tools.
>>
>
> Maybe he doesn't have the right lens for a 3 or 4 shot pano. Another
> "solution" would be to resize the 12 images first in Photoshop,
> GraphicConverter or The Gimp and then feed them into Hugin.

The output size will have a far larger effect than the input images.  
When I tested awhile ago, there was little difference in speed when  
stitching 6MP images down to a 5000 pixel wide pano compared to 1.5MP  
to the same output size.

Dennis - what were the output dimensions when you were having problems?

>> Yes it is normal for your CPU to be maxed out while an image is being
>> stitched.  This is an extremely CPU intensive task.
>
> Quit all other apps you don't need while stitching.

Yes, extremely normal. Any single-processor machine will become  
almost unusable for other tasks while stitching anything sizeable.

>>>> Second is that I only have about 4GB of HD space free on this
>>>> computer, and when I got up this morning I had a system error  
>>>> message

This is tight for OS X, especially when stitching - the OS will be  
using HD space for virtual memory, plus if you are stitching to multi- 
TIFF or Enblend each of the images will be saved at the final size of  
the panorama, possibly uncompressed - so my standard setup of 19  
shots stitched to 5000x2500 pixels uses around 700MB space just for  
the temporary files that are fed to Enblend.
Activity Monitor can show you how much space is being used for VM -  
click on the System Memory tab at the bottom and look for 'VM Size:'  
- my PB often runs at 4-7GB, G5 PM at 10-15GB.

>>>> (Mac OS X 10.4.3, iBook G4 933mhz 640MB DDR SDRAM)
>
> 640 MB RAM is close to nothing. Again, see Activity for usage of CPU,
> RAM etc. I just recently switched from a G4 867 MHz 1.12 GB RAM to  
> a G5,
> the G4 just crawled with my panoramas. Plenty of RAM now really helps.
>
> regards,
> Carl

As Carl says, 640MB is a starting point for panoramas. As an example  
with a big pano sized 20,000x10,000:

1GHz titanium PowerBook with 1GB RAM - 16 hours to remap to multi-TIFF.
2x2GHz G5 with 4GB RAM - 40 minutes.

That's using the PTMac stitcher which has lots of G5 and dual  
processor optimisations, but that's a 24-fold speed increase! Nona  
sees similar speed increases with extra RAM, but of course doesn't  
use both processors unless you start running two copies at once.

Ian