Registration RMS

[AnnDoro]

Hi!

For my research I try to retrace how the RMS for the registration (rough and fine) is calculated. Could someone tell me, how these RMS are calculated?

Thanks :)

[daniel]

I guess the 'rough' registration corresponds to the 'Align / point-pair based picking tool'?

'align rms' = RMS of the remaining distance between each pairs after registration (you can see the values in the right-most column once you get enough pairs)

'ICP rms' = RMS of the distance between each point (used at the last step of the registration process) of the aligned/data cloud and its nearest neighbor in the model/reference cloud. Depending on the parameters all points of the aligned cloud may not be used at each iteration.

You can compute a full RMS afterwards by computing the distance between both clouds (with Tools > Distances > Cloud/Cloud dist.').

[AnnDoro]

Yes, the 'rough' registration is the align with the picking tool.

So, the RMS is calculated by the sqaured distance between the data cloud and it nearest neighbour in the reference, divided through the number of points from data cloud and extract the root?

Thanks!

[daniel]

Yes it's the square root of the mean value of the squared distances:

Code: Select all

RMS = sqrt( sum(Di^2)  / N)

[AnnDoro]

Thanks!

[Leonardo Simic]

Thanks guys! Cheers!