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Date:   Fri, 7 Oct 2022 15:11:59 +0300
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Krzysztof =?utf-8?Q?Ha=C5=82asa?= <khalasa@piap.pl>
Cc:     Jacopo Mondi <jacopo@jmondi.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Sakari Ailus <sakari.ailus@iki.fi>, linux-media@vger.kernel.org
Subject: Re: [PATCH 02/10] media: ar0521: Add V4L2_CID_ANALOG_GAIN
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References: <20221005190613.394277-1-jacopo@jmondi.org>
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On Fri, Oct 07, 2022 at 01:56:11PM +0200, Krzysztof Hałasa wrote:
> Jacopo Mondi writes:
> 
> >> BTW ISP can't really do that color balancing for you, since the sensor
> >> operates at its native bit resolution and ISP is limited to the output
> >> format, which is currently only 8-bit.
> >
> > I'm not sure what do you mean here either :)
> 
> Well, the sensor does DSP on 12 bits internally, or something alike.
> Then it outputs (currently) 8 bits of data, the rest being lost. If you
> do color balancing etc. on this, you may get worse results (like color
> banding).

But if you apply colour gains in the sensor, they will apply before
black level correction or lens shading compensation in the ISP, which I
think will cause other issues, possibly worse.

Out of curiosity, if you can tell, what do you use this sensor with ?

-- 
Regards,

Laurent Pinchart