GTKD Cairo get pixel color

[TheDGuy via Digitalmars-d-learn]

On Friday, 1 January 2016 at 15:22:18 UTC, Mike Wey wrote:
> On 01/01/2016 01:37 PM, TheDGuy wrote:
>> [...]
>
> you would either cr.getTarget(); or 
> cairo.ImageSurface.ImageSurface.create.
>
> I'm not sure how those would get you access to the pixel data.

Okay, thanks for your answer.

So which function do i call with "cr.getTarget()" and how can i 
get the rgb-values of a pixel from it?