[libcamera-devel] [PATCH v2 3/4] ipu3: cio2: Change sensor size selection policy

[Kieran Bingham]

On 27/08/2021 15:07, Umang Jain wrote:
> Hi Kieran,
>>> +    float desiredRatio = static_cast<float>(resolution.width) /
>>> +                 resolution.height;
>>
>> Ok - so we always try to keep the sensor format that is close to native,
>> rather than the closest to what is requested.
>>
>> I'm not yet sure I understand why that is better, but this patch does do
>> what it describes, so on that aspect:
>>
>> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>>
>>
>> But does this mean that if I ask for a 16:9 1080p image, I'm going to
>> get a larger 4k image, which would then be perceptually squashed?
>>
>> The end result will still be cropped somewhere right?
> 
> 
> Cropping happens at 2 places, either at the (i) "source" which I
> understand is the actual sensor (ii) in the IMGU
> 
> The end result might be same/close, i.e. what you requested, but do you
> want your Camera sensor to run at 4k everytime 1080p is requested
> (provided it can do lower native resolutions too). No, right?


As long as an image from a FoV 4:3 sensor like this:

	https://pasteboard.co/KhPTc6U.jpg (4:3

becomes this

	https://pasteboard.co/KhPTHQm.jpg

and not this

	https://pasteboard.co/KhPTUeO.jpg

then it's fine ;-)