[ptx] Hugin + Duo Core

[Daniel M. German]

 Hal V Engel twisted the bytes to say:

 Hal> On Friday 21 July 2006 15:25, Ed Halley wrote:
 >> I have used Hugin on a MacBook Pro without problems.  However, as the
 >> optimizer and the stitcher are both single-threaded processes, it's
 >> not taking any special ADVANTAGE of the dual-core SMP nature of the
 >> beast, as far as I know.  The interface may be a bit snappier while
 >> the program is running, which is true of ALL applications running on
 >> any SMP architecture.
 >> 
 >> On Jul 21, 2006, at 4:12 PM, Marcelo Pereira wrote:
 >> > Hi there,
 >> >
 >> > Does Hugin support dual processor?
 >> >
 >> > See ya,
 >> > Marcelo
 >> 
 >> --
 >> [ e d @ h a l l e y . c c ]

 Hal> The Hugin stitcher that is in CVS is multi-threaded.  I have only tested this 
 Hal> on a linux box with an amd64 X2 and it ran great and reduced stitching times 
 Hal> by almost 50%.  I don't see how this would be different on a Mac or Windows 
 Hal> machine with a multi-processor setup.  

As I mentioned in my previous message, the speed-up will depend on
several factors:

* The size of the image
* The algorithm/program used (nona vs libpano, libpano is not multi-threaded)
* If masks are created
* The format of the output

If the image is large the photos will be re-mapped more quickly in a
multi-CPU/multi-core environment. But if your images are large and you
expect one of the complex outputs your CPU(s) will probably have to
wait for the disk.

For libpano (and before cropped-image processing), trashing was a big
performance killer in the creations of large panoramas. It is no
longer an issue unless you want to create a very large output image
(it is necessary to hold the entire image in memory at once: X * Y *
bytes per pixel, if you use masks multiply this by 2).


I haven't tested it myself, but I believe that only if you have a
small image, with TIFF (no mask) output you can get close to that 50%
improvement (using nona). But Pablo will probably have a better/more
informed answer.


dmg


--
Daniel M. German                  "If all mankind minus one,
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    John Stuart Mill ->            would be justified in silencing mankind."
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dmg (at) uvic (dot) ca
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