Auto detect not recognising coded targets

[John_H]

Attached is an image from a project which uses a scale bar featuring 12 bit coded targets.

The targets differ from the ones that come with Agisoft, in that they don't have a central black circle at the center of the target, but we've used these scale bars before, and Agisoft had no problem autodetecting the targets.

I'm guessing the problem may be the targets are too big in the image, (in the previous project they were far smaller) which would be annoying as the project requires close range detailed images. However, the target's white central circle appears to be under the 30pix diameter (25-29ish? see second attached image) that seems to be the maximal limit.

I've tried running the auto detect at every tolerance, inverted and non-inverted but with zero results. Detecting uncoded circles is partially successful; some of the targets are recognised in some images, along with full stops on the scale bars and even  bokeh circles from the out of focus background!

If the problem is the size, I'm guessing the solution would be to take an additional set of photos, with different camera settings,  from further away and then combine the two camera networks?

Any other ideas?

[Alexey Pasumansky]

Hello John,

Can you send a couple of the images where the coded targets couldn't be detected automatically to support@agisoft.com?

[John_H]

Thanks Alexey, I've sent a couple of images.

[wizprod]

The surrounding area is quite sensitive, and needs to be somewhat larger than the outer black circle. Is also seems that detection is done in a rectangle. so have that in mind when designing the targets.

Also take care that no shadows are cast onto the targets.

I have attached one of my targets. Plate is 60x40 cm, "active" area for the target is 40x40 cm, and outer black circle is around 30 cm in diameter.