Re: sharpen() CSS filter

On 21/10/2011, at 8:52 AM, Chris Marrin wrote:

> 
> In http://lists.w3.org/Archives/Public/public-fx/2011OctDec/0031.html, I suggested removing sharpen() from the CSS filter list. I'd like to break that issue out here for discussion.
> 
> My reason for suggesting this is because sharpen (actually an unsharp mask) requires several steps: blur, subtract, multiply and add (or something like that). This can be difficult to hardware accelerate on constrained systems, like mobile platforms. Also, sharpen doesn't seem to be a "core effect" like drop-shadow, blur and the color-matrix effects.
> 
> I think we should eventually add sharpen, as well as bloom, displacement, lighting and some of the other more complex effects. But for now I think we should stick with a small set that is easily accelerated.

Also, the majority of uses for sharpen beyond the most basic are better achieved through a custom sharpen (or enhancement) filter. 

Dean