Undistorted images have black borders

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13 comments

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    Götz Echtenacher

    I've noticed this in other programs as well - would be interesting to know the reason...

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    ssh4

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    Götz Echtenacher

    Thank you Vlad!

    I didn't notice that they have been undistorted in RC.

    What I meant is that I imported undistorted images from somewhere else (3 guesses !) and they had all one perfectly straight black strip. Can't have been due to the undistortion because otherwise they wouldn't have been perfectly straight (and also exactly the same).

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    ssh4

    Lens settings estimation can't be perfect. Especially for not expansive lenses used in multicamera rigs.
    But this lens can have near zero distortion, so photogrammetry tool just shift principal point.

     

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    Götz Echtenacher

    Ah, so that's probably what happened in my case...

    But why would RC shift this principal point from a set of images that was already quite well aligned?

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    ssh4

    For example sensor optical stabilisation - correct reason.
    Or false positive feature matches - incorrect.

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    Götz Echtenacher

    But for all of them absolutely identical?

    That doesn't match for either...

    Oh well, another mistery...  ;-)

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    ozRocker

    No difference for me even when I use "Inner region"

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    ssh4

    Marcus.

    You can play with Resolution settings. And with Enabling/disabling Principal point undistortion.
    In case you do not like black borders.

    But, will be better understand what problem you want solve? Because this black borders must not used by any other photogrammetry software.

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    Götz Echtenacher

    Hi Marcus,

    did you re-align after you changed the setting?

    You might want to delete all components before you continue since RC uses existing ones in the project as a starting off point, which might explain that...

    Also, does it affect your result in any negative way? because in theory RC ignores unicolored areas. It is quite possible that the areas are noch black but transparentm at least within RC.

     

    Hi Vlad,

    do you mean that one shouldn't use those undistorted images in other software? Or that other software will ignore it as well?

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    ozRocker

    Its the same problem even if I start from a new project.

    I'm trying to create texture in another photogrammetry program but because of the black lines, I get lines on the mesh after building the texture.  It looks like slash marks

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    ozRocker

    Ok, you are correct that proper photogrammetry software can ignore alpha.  I found the setting to enable that and it works now.  Thank you!

    For anyone else reading this, I'm not jumping ship and leaving Reality Capture.  This software is still far superior to anything else out there.  I'm just experimenting with texturing 

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    ssh4

    Marcus, that what I want to know.
    If you use Bundler export, really big chance that it have a bug. And this is not a problem with border, this is error in values. That affect wrong texture generation in some other well known software. Team working on its fix, but no eta :(

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