In theory if you've got distance information and can keep the phone at a known angle in relation to the item differentiating between 27 and 29 mm shouldn't be an issue.
What the photo bits will not be able to do without significant user interaction is determine other key properties of the fastener including material strength and likely finish. It's a cute gimmick though.
> determine other key properties of the fastener including material strength
Given a random screw, can anyone determine material strength using household items? If so, I would definitely like to apply this to some personal projects I am working on!
> Given a random screw, can anyone determine material strength using household items? If so, I would definitely like to apply this to some personal projects I am working on!
Yes. Fasteners are typically marked on the head/face.
What the photo bits will not be able to do without significant user interaction is determine other key properties of the fastener including material strength and likely finish. It's a cute gimmick though.