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Reference a Photo Accurately

Learn how to improve the referencing of your Veezer photos.

This page is about photos acquired in Veezer app. For imported photos, see Import and Reference Photos.

There are two key points to reference Veezer photos accurately:

  • Camera calibration.
  • Control points.

Camera Calibration​

Follow the Veezer recommentation by calibrating properly your camera.

See Camera Calibration

Take Control Points​

Control points are used both to check and to adjust the photo referencing.

Veezer recommendation is to take one control point per photo, but if you target more accurate positioning, you can take more points:

  • A single control point allows for 4 to 6 times more accurate positioning.
  • With 3 control points we get again a 2 to 4 times more accurate positioning.
  • With 6 control points or more we can adjust more parameters like camera position and get an even more accurate positioning.

Follow the recommendations to create control points:

  • The control point must be at least 300 m (1000 ft) from the photo to obtain good accuracy.
  • The greater the distance, the more accurate the control point will be.

You can take control points:

Manage Photo Referencing​

Use the Photo Referencing screen to check and improve accuracy.

Check visually your control points and the reprojection error display.

Check the Photo Referencing screen Status to get an estimate of global precision.

When using more than 6 control points, you can adjust camera position and improve positioning in case of inaccurate photo position.

What you can try to imrove precision or to solve any positioning issue:

  • Take more control points
  • Disable/enable some control points
  • Fix the initial position: sometimes the position provided by the GPS is not accurate enough. If you know it precisely, you can enter it.
  • Play with Photo Referencing Computing/Adjustment options, position and optical properties adjustment may improve the precision.
note

If you notice that adjusting optical properties improves photo positioning, it may be a good news for your photo, but it means that your camera calibration is weak, and could be improved for all your photos.