preserveAlpha unpremultiplies?

I just noticed that the description of the preserveAlpha attribute of 
the feConvolveMatrix filter says this:

"A value of true indicates that the convolution will only apply to the 
color channels. In this case, the filter will temporarily unpremultiply 
the color component values, apply the kernel, and then re-premultiply at 
the end."

Am I reading this correctly to mean that if preserveAlpha is true that 
it operates on non-premultiplied colors? If so, why?

Received on Friday, 10 December 2010 07:23:40 UTC