Big Warp Affine to Bdv Affine

Hi @bogovicj @NicoKiaru

When printing the Big Warp transform I get something like this:

3d-affine: (0.2631659750292986, 0.2728152883093439, -0.8421807709743863, 246.3565248635497, -0.5994842563176209, 0.7014132763310869, 0.039887406048063165, 128.0280556665454, 0.6513948564132443, 0.5352982320152232, 0.37695292383424855, -147.204085589971)

I tried putting this transformation into a bdv.xml file but the image is not transformed the same way as in Big Warp. Do you know how I have to convert the numbers such that they work in a bdv.xml file?

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Hi Christian,

Can you share the example file ? It will be easier to see what could be the issue.



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Here are the files. The moving image is the x-ray.

Havn’t looked into your links yet but here’s something to keep in mind.

The bigwarp affine transforms physical space to physcial space. So if your image had any non-identity pixel-to-physical transformation (pixel size not equal to 1.0), then you may have to concatenate what bigwarp spit out with the pixel to physical transformation.


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That crossed my mind as well, however in this case both images had 1.0 (micrometer) isotropic pixel sizes.

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Is Big Warp affine moving to fixed or fixed to moving?

it’s fixed to moving.
(also how did you pull the affine out?)

Press P; see BigWarp help :slight_smile:

Aha. Then I have to invert it for Bdv when I want to apply it to the moving?!

LOL, I’m so out of it :sleeping:

oooo, yes, likely. keep us posted

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works :slight_smile:


Happy to be your Debug duck :duck:



And, after having obtained some more grey hairs in the mysterious land of transform conversions, I am happy to present another one:


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