Sharper photo overlay

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mankoff
Posts: 26
Joined: Sat Oct 29, 2011 8:12 pm

Sharper photo overlay

Post by mankoff »

Hi,

I have a 3D model generated from photographs and the structure-from-motion algorithm in PhotoScan. A screenshot of that is here:
PhotoScan screenshot.
PhotoScan screenshot.
photoscan.png (115.08 KiB) Viewed 8252 times
When I export that model (PLY + JPEG) and import it into qCC, it looks like this:
qCC screenshot
qCC screenshot
cc.png (92.78 KiB) Viewed 8252 times
Why is qCC so fuzzy? The JPEG overlay appears sharp. Is there something I am doing wrong, or is this an implementation issue, in which case, should I file a feature to have sharper photo-realistic overlays as an option?

Thanks,

-k.
daniel
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Location: Grenoble, France
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Re: Sharper photo overlay

Post by daniel »

Hi,

it's just a guess, but the result in PhotoScan seems to be a textured mesh. The mesh displayed in CC seems to only have an RGB field (and it can't be otherwise as PLY files doesn't provide a standard way to exchange textures, only texture coordinates - see http://www.agisoft.ru/forum/index.php?topic=16.0). If you can work with OBJ format it would be preferable.

However I never encountered a PLY file with texture-related information. I would be greatly interested in it.
Daniel, CloudCompare admin
mankoff
Posts: 26
Joined: Sat Oct 29, 2011 8:12 pm

Re: Sharper photo overlay

Post by mankoff »

Yes the OBJ file makes it look just like it does in PhotoScan.

The PLY + overlay is exported from PhotoScan as a PLY file and a JPEG. Just like the OBJ is exported as an OBJ + JPEG. I assumed CC was loading the JPEG to give it the fuzzy texture, although maybe that information is encoded in the PLY? I can send an example if you like.
daniel
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Location: Grenoble, France
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Re: Sharper photo overlay

Post by daniel »

Yes, don't hesitate to send me the dataset.

From what I read, it seems that it's the responsibility of the user to load the JPG and manually 'associate' it with the mesh (there's no way to encode this in the PLY file).
Daniel, CloudCompare admin
mankoff
Posts: 26
Joined: Sat Oct 29, 2011 8:12 pm

Re: Sharper photo overlay

Post by mankoff »

Here is a data set, PLY and OBJ. https://dl.dropbox.com/u/12453163/cc.zip

The PLY file has "comment TextureFile subglacial.jpg" and MeshLab auto-loads the JPEG with the PLY.

-k.
daniel
Site Admin
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Joined: Wed Oct 13, 2010 7:34 am
Location: Grenoble, France
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Re: Sharper photo overlay

Post by daniel »

Ok, I've just added this functionality to the PLY loader.
Daniel, CloudCompare admin
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