Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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New AWB algorithm - NoIR camera support

Wed Jul 17, 2019 9:02 am

For some weeks the firmware has been using a new AWB algorithm that no longer uses the quad processors in the GPU. This change was needed to support the Pi4.

On the whole this produces results similar to the original algorithm. However, there is a difference when using the NoIR camara. Using the default settings will sometimes result in purple images!

To compensate for this purple tinge, there is a new AWB mode. When using raspicam applications (e.g. raspistill) you can set this new mode using
raspistill -awb greyworld ....
We recommend this setting is used at all times when using the NoIR camera.

Currently (17th July 2019), this change has not made it to the standard distribution although the firmware can be updated using rpi-update. and you can get the linux side code changes here https://github.com/raspberrypi/userland/pull/560. It should be installed as standard within a few weeks and I will update this thread when it is all available using the standard routes.

See this github thread for more technical information. https://github.com/raspberrypi/firmware/issues/1167
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Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: New AWB algorithm - NoIR camera support

Mon Jun 22, 2020 2:27 pm

As of the firmware from the end of March 2020, there is an additional config.txt option of "awb_auto_is_greyworld=1" which switches the standard "auto" mode to using greyworld for when it isn't possible or practical to rebuild an application or library that doesn't support greyworld directly.
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