[CREATE] Transparency (was: Questions and reflections about gradients)

[Olivier BERTEN]

Le 04/11/10 05:25, Jon Cruz a écrit :
> On Nov 3, 2010, at 5:34 PM, Sven Langkamp wrote:
>> * I'm not sure yet how to deal with transparency. My first option would
>> be to say: we're talking about color gradient and transparency isn't a
>> color attribute, it's an object or painter attribute, so we leave it out
>> completely. There's the Adobe's option to have a transparency gradient
>> next to the color gradient but then again, why not really differentiate
>> things and really separate them... But at least it would cover that
>> feature because I really think including transparency into the color
>> definition is wrong.
>>
>> Transparency is at least needed for the stops, so it's linked to the stop color anyway. The application can still decide if it wants to use the transparency or not.
> I've found that there are two main conceptual models for transparency. One is where transparency is associated with each color stop. The other is when transparency is set via an explicitly separate set of transparency stops that are independent of the color stops. Photoshop has separate transparency stops. GIMP, SVG and CSS have transparency as part of color stops. There are merits for both, and and users may different ones depending on the immediate situation of the specific project they are working on.
>
> Supporting either might be good. One can tag them as such. Of course, for any advanced editing software the difference can be implemented behind the scenes and allow users to use either view at will for editing.
>
> BTW one main factor in consideration for not just converting between the two forms is that data conversion errors can accumulate and shift things visibly.
My problem with that transparency question is that in my opinion, it has
really nothing to do with color. For me, transparency has as much in
common with color than size or position has.

By the way, that's how Scribus works... Transparency is an item as it,
next to color, dimensions or shape...

Olivier