[ptx] largest nona image possible?

[Pablo d'Angelo]

Hi Ed,

On Sat, 08 May 2004, Ed Halley wrote:

> 
> I'm unable to stitch 18Kx9K 12-image panoramas with nona, even going
> straight to a flattened JPEG, because nona requires the remapped layers
> to remain resident for the entire run.  On RHEL3, the working set grows
> to 3GB and dies, even though the final image is less than half of 1GB
> uncompressed.
> 
> (At least, my version requires that-- cvs seems to be down.)

Which version of nona have you tried? I have started to rewrite the stitcher
(the new code is in Stitcher.cpp / Stitcher.h) to address the point of keeping
everything in Memory (like SimpleStitcher.h) did.

The TIFF_m stitcher only keeps the currently remapped image in memory.

I've also changed the single image stitcher (with blending) to the
following algorithm:


for all images
   remap image
   calc blending seams, in overlapping parts of pano
                        and remapped image.
   blend into pano canvas

However, soft seaming (TIFF_mask and TIFF_multilayer_mask) is not implemented
yet (busy with low level import/export stuff, and nona bugfixes).

This should work quite nicely, except for the 360° case, where
the overlapping area can become the whole panorama,
for images stretching across left and right border, and the seam calculation
becomes very slow (have to check why).

Probably I should write some additional iterator, that can
"wrap around" at the borders, and use that.

The next step would be to swap the pano to disk and keep
only the image data needed for the current blending area in memory.

The best thing would be if a "per scanline" processing model
could be used, but I think that causes to many constraints, and
wouldn't work with algorithms like the pyramid blending.

ciao
  Pablo