[libcamera-devel] [PATCH 3/6] android: jpeg: exif: Fix setOrientation EXIF values

[Laurent Pinchart]

Hi Paul,

Thank you for the patch.

On Thu, Jan 14, 2021 at 07:40:32PM +0900, Paul Elder wrote:
> The input to setOrientation is angle clockwise from 12 o'clock, while
> the EXIF output values were swapped for 90 and 270 degrees.
> 
> From the EXIF spec:
> 
> 6 = The 0th row is the visual right-hand side of the image, and the
>     0th column is the visual top.
> 8 = The 0th row is the visual left-hand side of the image, and the
>     0th column is the visual bottom.
> 
> 6 should be 90 degrees clockwise, while 8 should 270 degrees clockwise.
> Fix this.

https://lists.libcamera.org/pipermail/libcamera-devel/2020-September/012647.html

The important part is that "Android defines the rotation as the
clockwise angle by which the image needs to be rotated to appear in the
correct orientation on the device screen". Could you read the thread and
let me know if you still think the current implementation is incorrect ?
Does this patch fix an issue you've noticed, or does it stem from
reading the code only ?

> Sogned-off-by: Paul Elder <paul.elder at ideasonboard.com>

Sogned-off-by ?

> ---
>  src/android/jpeg/exif.cpp | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/src/android/jpeg/exif.cpp b/src/android/jpeg/exif.cpp
> index 33b3fa7f..b19cb4cd 100644
> --- a/src/android/jpeg/exif.cpp
> +++ b/src/android/jpeg/exif.cpp
> @@ -263,13 +263,13 @@ void Exif::setOrientation(int orientation)
>  		value = 1;
>  		break;
>  	case 90:
> -		value = 8;
> +		value = 6;
>  		break;
>  	case 180:
>  		value = 3;
>  		break;
>  	case 270:
> -		value = 6;
> +		value = 8;
>  		break;
>  	}
>  

-- 
Regards,

Laurent Pinchart