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How to verify that the Camera Model associated to the Camera is Correct - PIX4Dmapper

If the camera model associated with the images of the project is not correct, it can lead to processing failure. This article explains how to verify that the camera model associated with the images of the project is correct.

To ensure that the correct camera model is used:

1. Click Project > Image Properties Editor...

PIX4Dmapper open image properties editor


2. In the Image Properties Editor, under the section Selected Camera Model, click Edit... to verify the camera model. If more than one camera model is selected, please verify each camera model.

PIX4Dmapper open edit camera model


3. In the Edit Camera Model pop-up, under the section Camera Model Parameters, verify that the correct lens type is selected. If a perspective lens is used, Perspective Lens has to be selected. If a fisheye lens is used, Fisheye Lens has to be selected.
4. In the Edit Camera Model pop-up, under the section Camera Model Parameters, verify that the parameters are correct:

Perspective Lens

PIX4Dmapper perspective lens camera model

      • The Sensor Width has to correspond to the real sensor width.
      • The Focal Length should be the real focal length.
      • The Principal Point should be close to the center of the image, ,i.e. the Principal Point x coordinate should be approximately half of the sensor width and the Principal Point y coordinate should be approximately half of the sensor height. If processing fails, it is recommended to set the Principal Point in the center of the image.
      • The Radial and Tangential Distortions should be between -1 and 1. If processing fails, it is recommended to set them to 0.

Fisheye Lens

PIX4Dmapper Fisheye lens camera model

      • The Sensor Width has to correspond to the real sensor width.
      • The Principal Point should be close to the center of the image. I.e. the Principal Point x coordinate should be approximately half of the sensor width and the Principal Point y coordinate should be approximately half of the sensor height. If processing fails, it is recommended to set the Principal Point to be in the center of the image.
      • If processing fails, it is recommended to set the values as following:
        • Polynomial coefficients: 0, 1, 0, 0, 0.
        • Affine transformation C = image width in pixels.
        • Affine transformation D = 0.
        • Affine transformation E = 0.
        • Affine transformation F = image width in pixels.

Shutter Model

If the Readout is fast, then the Global Shutter or Fast Readout model should be selected. If the image is scanned line by line, the Linear Rolling Shutter Model should be selected (How to correct for the Rolling Shutter Effect).

If the parameters are not correct, edit the camera model. For more information on how to edit the camera model: How to use the Editing Camera Model Options.