Lytro as potential 3d scanner

You may have seen recently news about the Lytro camera. It's what they're calling a 'light field' camera (see their website for the technical details).

Anyway, the images it produces allows you to select the focus after you take the photo. I think it's only a short step away from creating a point cloud. it might even create a point cloud in order to do the focusing.

it's obvious (to me at least) that if you, say, set the focus to 1 meter, record all the in-focus pixels, and then step out a cm, repeat, etc. to infinity, you can assembly a height map of the image.

I don't know what focus precision the camera has, and of course it would only be from a single perspective, but it is still an interesting technology that will only improve with time.

I'd imagine a marker object of known size (it could be anything, a scale printed on paper or anything we can 3d print) would improve the accuracy of the dimensions of the height map.

Anyway, I just wanted to point out this new technology and how it might apply to our hobby.

... some years ago I've developed some optics and methodes for stereo-vision with extreme high fields-of-view for microscopy.

The easiest approach were special multi-part rod-lenses - the more complex but accuratest was a simple lens-array placed on a camera-sensor with high resolution and biggest possible size.

Imagine a snapshot image composed of an array of say 500x500 small sub-images each representing the view through one of the small lenses in the grid from a slightly displaced point.

Now you can recalculate any view and focus of the complete image area/volume by simply using only the corresponding pixels from the sub-images that represent the selected angular view.

It's similar to selecting a specific view from a holographic image.

You can find some background to this by searching for "plenoptic": [en.wikipedia.org]

Maybe even more interesting is, that you don't need a zoom-objective or any other lenses - simply fit a thin sheet with a lens-array on a 'naked' camera sensor and recalculate all zooming within the sub-images ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I think the most exciting part of the technology is the scalability. We're talking about real computational photography, so rather than expense scaling as you need an increasingly intricate sensor/mechanism to capture your point of view, Lytro will eventually be able to stack their light sensor units next to each other in the same or seperate devices, and see an increase in quality with each sensor added.

Just wait til we get to videocameras using this tech, they will functionally be single pass additive optical 3d scanners where the longer you're filming the better the geometry - This could be the basis for real holograms.

Right now the proprietary format is limited and the license stifling - How fast we get to the really cool stuff is going to be a function of if they hold onto all the licensing and try to keep all R&D knowledge in-house, or if they open it up for the enthusiast community to go nuts on. I think we're all rooting for the latter.

... all the patenting only covers their special design ...

For 'holografic video-cameras' you can use the 80-something years old infos about 'plenoptics' - a simple description: design an 'areal camera' consisting of many small, cheap camera-sensors with something like 100x100 pixels each, arrange them to an array of lets say 500x500 sensors (the same as a big camera-sensor with 50000x50000 pixels and a lens-array of 500x500 lenses attached to the sensor).

Then transfer this image to a big diplay with 50000x50000 pixels and a lensarray of 500x500 lenses on them, so you'll get the same geometric setup.

Then you'll see the complete 3D-lightfield (same as an hologramm) through the display-lenses, that the 'areal camera' received ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]