Circular images

The images acquired by my camera+fish-eye lens are not circular. Is it still possible to use this system?

You need to calibrate your fish-eye+camera system.

Example of truncated image:

The fact that you obtain an image that is truncated on the edges indicates that the field of view of your camera is less than ±90° in every direction. Therefore, only a part of the information on the gap fraction angular variation is available to derive PAI (Plant Area Index).

The field of view of the lens is generally provided by the manufacturer. However, it often corresponds to the field of view in the diagonal of the image. Example of images acquired with different fish-eye lens are provided below.

it is required to calibrate the camera+fish-eye system. CAN-EYE proposes a technique and a module to help for the calibration (see Documentation).


Example fish-eye, FOV 90° in the diagonal, 60° top


Sugar Beet DHP

FOV in the diagonal ± 90°

FOV in height about ±60°

FOV ±60° on the edge of the circle

FOV ±90° on the edge of the circle

Modification date : 20 June 2023 | Publication date : 27 July 2010 | Redactor : M. Weiss