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Re: problem with grid/collection stitching

Posted by Jan Eglinger on Aug 24, 2016; 7:57am
URL: http://imagej.273.s1.nabble.com/problem-with-grid-collection-stitching-tp5017105p5017107.html

Dear Aryeh,

I didn't have time to check out your images yet, but had some problems
with misalignment in the past as well. See also this discussion on the
ImageJ forum:
http://forum.imagej.net/t/limit-the-tile-displacement-in-stitching/424?u=imagejan

If I understood correctly after looking at the source code, the max/avg
displacement parameter defines how far each tile can deviate in the
global optimization from its computed position in the pairwise alignment
with each overlapping tile. That means if the pairwise alignment
returned "wrong" values, the tile will get misaligned no matter what are
its coordinates defined in the TileConfiguration.txt.

Maybe Stephan Preibisch can comment more on that.

Best regards,
Jan


On 24.08.2016 05:49, Aryeh Weiss wrote:

> I am having trouble with stitching the following set of images (filename
> defined positions):
>
> https://drive.google.com/file/d/0Bytu294eIohjUE5waC1EQUhfZE0/view?usp=sharing
>
> The above link is to a zip file that contains the 120 tiles that I am
> trying to stich (nominally 10% overlap)
>
> With the default parameters, the following is obtained, with many
> "misplaced" tiles
> Here is a link to what I get.
> https://drive.google.com/file/d/0Bytu294eIohjbzYwWG15bW5qWEk/view?usp=sharing
>
>
> If I reduced the regression threshold to 0.02 (from 0.3), it is better,
> but I still have the (1,1) tile misplaced:
> https://drive.google.com/file/d/0Bytu294eIohjbDQ0N2VxVVVuUVE/view?usp=sharing
>
>
> If I repeat with the smaller regression threshold, but I only stitch the
> top half of the image, including the (1,1) tile, it works correctly.
>
> By eye it looks like I have enough  "structure" (marks, spots, etc) to
> align. In any case, I dont see how it can get so misalligned, even when
> I reduced the max/avg displacement.
>
> Is there something inherently wrong with  with my images? Is there a
> better set of parameters which I can use to get it right.
>
> Thanks in advance for any help you can provide.
>
> --aryeh
>

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