Meshroom - Transparent/Solid backgrounds?

[Jerald A.]

Is it possible to scan an object if all the pictures have a transparent or solid color background?

I have similar pictures, and I can't get pass the StructureFromMotion node.  I assume it's because my background has no detail or interesting markers.

[Denis]

I don't thing this is an issue, as long as there isn't a pattern in the background that does not match to the position of the object, for instance, if you turn the object itself and Meshlab align things in the the background.

I am currently experimenting with featureless background (dark), to be able to add the bottom of the object, so that the 3D model is visible from all angles, and so far, it usually work. The worse case for me is when Meshlab does not have enough features to link photos from the bottom and the rest.

I have not tried transparent background though, but I did but my objects on a piece of glass to avoid shadows on the background.

On 10/12/2021 23:56, 'Jerald A.' via AliceVision wrote:

Is it possible to scan an object if all the pictures have a transparent or solid color background?

I have similar pictures, and I can't get pass the StructureFromMotion node.  I assume it's because my background has no detail or interesting markers.

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[Simone Gasparini]

If you are taking pictures around the object or the object is rotating on a e.g. turntable then check the feature extracted from your images by clicking on the icon with the 3 dots

That will show if there are too many features extracted on the background. If you are using Sift in the latest version it is likely the case and the multi-body scenes are not handled correctly if there are too many features on the background.

You can try to use Akaze features that have different settings and they are likely to extract only relevant features on the object of interest rather than the background.

Feel free to share some images 

S.

On Fri, Dec 10, 2021 at 11:56 PM 'Jerald A.' via AliceVision <alice...@googlegroups.com> wrote:

Is it possible to scan an object if all the pictures have a transparent or solid color background?

I have similar pictures, and I can't get pass the StructureFromMotion node.  I assume it's because my background has no detail or interesting markers.

[Jerald A.]

Thanks for the reply.

So, if I have turntable style setup with a featureless background, there are better settings available than
the default settings?  I checked the feature extraction details.  Nothing in the background is marked, only
the object is marked.  I checked both Sift and Akaze.

I found some more parameters here:
https://meshroom-manual.readthedocs.io/en/latest/faq/reconstruction-parameters/reconstruction-parameters.html

My pictureset is sparse, less than 15 images, so I follow guidelines under "Sparse reconstruction".

DescriberTypes: akaze, sift checked
Describer Density: Ultra
Describer Quality: Ultra
Guided Matching: enabled
minInputTrackLength: 3

I'm thinking now I may simply need more images.