RADI Radial symmetric lens distortion
Columns | format | contents/explanation |
|---|---|---|
1-4 | A4 | RADI (format free) |
| A | Camera name |
| F | Step width for the distortion values |
| nF | Distortion values in 1/1000 units of the photo coordinates, i.e. μm |
By means of a RADI statement, RELAX and BINGO can consider a known radial symmetric lens distortion. In this case corrected photo coordinates will be used in the adjustment.
The input is format free. The values have to be separated by at least one blank. If the input is longer than the 100 columns of an input line, data may be continued in the next line. A consecutive line will be recognised by an "&"-sign.
The camera name consists of up to 15 characters. The uniform step width for the distortion is a real value without sign and must be given in millimetres. The distortion values are real numbers and must be given in micrometres. The first value of the distortion profile is fixed in BINGO with r0 = 0.0. The first input is expected for r1 = step width. (This differs from several photogrammetric systems where the first input is expected for r0 = 0.0.)
The radius of the last step should be a little higher than the maximum image radius.
Example:
┌────── Camera name │ │ ┌────── Step width [millimetre] │ │ │ │ ┌────── Distortion for r1 [micrometre] │ │ │ │ │ │ RADI 2 10.0 -3.0 -6.0 -7.0 -6.0 -4.0 -2.0 0.0 2.0 2.0 & -1.0 -3.0 -6.0 -5.0 -1.0 17.0 |
The origin of the distortion profile is the origin of the photo coordinate system. Therefore the fiducial reference coordinates for the interior orientation or for the transformation have to be related always to the principal point of symmetry PPS, i.e. PPS has the coordinates (0,0).
A maximum number of 40 distortion values can be processed.
If additional parameters are applied, BINGO computes an average radial symmetric distortion profile from these additional parameters.
In case of a simultaneous use of a RADI statement for the camera the sum of both influences will be output in the BINGO LIST file. For those cases the number of listed distortion points is defined the maximum image radius.