Re: [RFC PATCH] omap3isp : fix cfa demosaicing for format other than GRBG

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jean-Philippe,

On Tuesday 29 May 2012 10:24:45 jean-philippe francois wrote:
> Hi,
> 
> omap3 ISP previewer block can convert a raw bayer image into a UYVY image.
> Debayering coefficient are stored in an undocumented table. In the current
> form, only GRBG format are converted correctly.
> 
> However, the other CFA arrangement can be transformed in GRBG arrangement by
> shifting the image window one pixel to the left or to the bottom.
> 
> Here is a patch against vanilla 3.2.17, that was only tested with a BGGR
> arrangement.
> Is it the right way to fix this issue ?

That's really a hack. I'd much rather support other Bayer orders properly by 
modifying the CFA coefficients table.

The table is arranged as 4 blocks of 144 coefficients. If I'm not mistaken (I 
haven't tested it), the blocks should be arranged as follows:

GRBG 0 1 2 3
RGGB 1 0 3 2
BGGR 2 3 0 1
GBRG 3 2 1 0

Would you be able to test that with your BGGR sensor ?

If that's correct, it shouldn't be too difficult to modify the order 
dynamically based on the format.

-- 
Regards,

Laurent Pinchart