[cairo] Image Format / Pre-Multiplied Alpha Related Feature Request

[Bill Spitzak]

On 01/28/2016 11:47 PM, Tavmjong Bah wrote:
> On Thu, 2016-01-28 at 17:18 -0500, William Kappler wrote:
>> Thanks for the suggestion.
>>
>> I'm not dealing with a single color, but that did give me an idea
>> that perhaps I could render color without alpha and then alpha on its
>> own, and just blend the data together on my end. I'm not sure if that
>> will work or not, I need to play with it.
>>
>> A floating point format would be great, though, if that's possible at
>> some point in the future. It would potentially have utility beyond my
>> specific usage.
>
> We (Inkscape) would love to see a floating point format to avoid issues
> such as banding in gradients.

Dithering would also work here. Calculate the gradient in floating point 
(or high precision of some sort) and then add noise before converting to 
8 bits. That hides the banding quite well and makes the gradients look 
really smooth.