KIRI Innovation

Photogrammetry: how to scan featureless, shiny, black or transparent objects

Photogrammetry: how to scan featureless, shiny, black or transparent objects

In recent, many customers or backers emailed us asking about how to scan featureless objects with photo mode in our Phiz App “3DScanLink”.

 

Thanks to Erik Christensen who shared a great tutorial video on YouTube. In this video, Erik demonstrated a simple but useful way to scan featureless, shiny, pure color or transparent objects.

 

In case anybody do not familiar with photo mode (photogrammetry), please read explanation below and see why features are important:

Photogrammetry is, in general, a technology to calculate 3-dimentional coordinates of an object by analyzing the features on the overlapping photographs of the object. If less features on the object, it will be hard for algorithm to calculate the pose of the camera and the 3d information of the object.

So the basic idea to improve the scan result of featureless object is to increase the number of feature points. Here is an example:

Original scan

We took 30 photos around a pure black gear from our Phiz 3d scanner. After processing with our photogrammetry algorithm and we did not get a decent result.

Talcum powder and brush

So we bought talcum powder and brush to apply additional “features” on this black object. 

Gear with dust

We took same amount of photos around this applied dust gear and process with our algorithm, and let us see what we got from 3d reconstruction.

After scan

It shows a huge improvement compare to the original result. And now it’s measurable. This is a simple experiment and the 3d model is not perfect due to insufficient number of photographs from bottom direction. But it proves the idea and it is an easy and cheap way to do scan on featureless objects. If anybody have similar demand, just give it a try.