On Track Towards Autonomy: Cameras

Cameras: a well-known ally

Zoom in: the right camera and its settings

  • The aperture, also referred to as the f-stop number, is part of the camera lens specifications. It defines how much light passes through the lens onto the camera sensor. Since these sensors can be affected differently by the aperture, camera manufacturers often provide advice for the ideal lens pairing.
  • The ISO indicates the sensor’s level of sensitivity to light. Increasing it improves the visibility under low-light situations, i.e. at night, but also induces noise in the images: the correct balance must be reached.
  • The shutter speed defines how long the shutter remains open for each frame capturing. Expressed in milliseconds, the greater its value, the longer the shutter remains open and the more light reaches the sensor. A long exposure time improves visibility in low-light situations, but also increases the sensitivity to motion, resulting in a phenomenon called “motion blur” on the images, which is to be avoided. Yet, an excessively short exposure time is not better: since traffic lights emit signals at their own frequency, such a configuration can result in capturing frames while the road sign is not transmitting any light, thus appearing “off” on the image. This — briefly explained — LED flickering issue is a challenge well known in the machine vision community, and another reason why properly configuring the camera shutter speed is essential for an ADAS application.

Camera integration

Zoom out

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