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p4b file format

Hi,

Is there anyone who knows the p4b file structure?

I would like to get the sparse point cloud from result_tracks_full_1.p4b, but can’t figure out how to parse the binary file.

Following files seem to have equivalent information, but without Automatic Tie Point ID.

result_tracks2_full_1.las
result_tracks3_full_1.las

Thank you very much for your help in advance.

Hi @k.y.koo,

The p4b format is only readable in the rayCloud so only by Pix4Dmapper.

Additionally, Pix4Dmapper doesn’t store information about the sparse cloud - Automatic Tie points in one file. And, only some values can be found in the params folder:

  • Number of the point --> bingo file (1 column)
  • Photo ID --> bingo file (photo ID written before the ATPs related to it are listed)
  • Pixel coordinates x y --> bingo file (2, 3 column)
  • Coordinates x y z --> uncertainties file (1, 2, 3 column)
  • Reprojection error x,y,z --> uncertainties file (4, 5, 6 column)

Note that not all the automatic tie points are listed in the “params” output files and that it is not possible to correlate the values in bingo and uncertainties file.

I hope it helps,

Regards