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Very small targets (.5")

February 20, 2015 - 1:43pm #1

Hi,

I'm trying to get some targets to work but they have to work on a very small surface, about 1/2 an inch. I can get the targets to work reliably at 1 inch or so, but when I shrink it down to 1/2 inch they stop working completely, even though they appear clearly on camera.

Is this something that can be done reliably at such a small size?

Thanks,

Kevin N.

 

Very small targets (.5")

March 26, 2016 - 10:14pm #6

Hi , 

I am trying to use small treacker like you did.

Can you maybe share your 0.5inch treacker ? 

 

Very small targets (.5")

February 27, 2015 - 9:35am #5

I've tried that on Android (at least, I think that's the default, since it's stops focusing soon after the app starts). The problem there is that it focuses further out than the camera is capable of. I'll play around though. Thanks for the suggestinos.

Very small targets (.5")

February 26, 2015 - 10:47pm #4

Vuforia does not support camera zoom;  ... IMO, if the device has troubles staying focused at close range, the best option is probably to use FOCUS_MODE_MACRO (i.e. disable Autofocus) and see if it gets more stable. 

 

 

Very small targets (.5")

February 26, 2015 - 9:31pm #3

That's great info. Thanks for that.

I did have some pretty good results at .5" with certain types of art (printed pixel art works great). We actually need to go just a little bit smaller, to like .375", and that's where I'm running into trouble. I can get it to track, but it's not stable. The problem is that the phone (iPhone 5S in particular in my testing) just has a hard time staying focused on the object when it's that close, and it needs to be that close for the image to be large enough in the camera feed to track. I wonder if a digital zoom would be enough to make it work. I know we lose fidelity with a digital zoom, but I wonder if there'd be enough image data if we cut some of the superfluous camera edges out. Is there a way to set the camera to zoom?

Thanks,

Kevin N.

Very small targets (.5")

February 23, 2015 - 3:47am #2

For Image Targets, a size of "0.5 inch"  sounds like fairly challenging;

the developer guide provides some guidelines here:

https://developer.vuforia.com/resources/dev-guide/image-targets

Size

For tabletop, near-field, product shelf and similar scenarios, a physical printed image target should be at least 5 inches or 12 cm in width and of reasonable height for a good AR experience. The recommended size varies based on the actual target rating and the distance to the physical image target. 

 

Perhaps it might still potentially work provided that you do the following:

- the device is kept fairly close to the target (e.g. less than 10 inches from target), so that the target details are well visible in the camera image, and in good focus

- the focus is adjusted appropriately (e.g. you could use either the FOCUS_MODE_CONTINUOUSAUTO or the FOCUS_MODE_MACRO focus options as explained here: https://developer.vuforia.com/resources/dev-guide/continuous-autofocus-and-other-focus-modes

- the flash torch may also help if working in low lighting conditions

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