Does HTML define browser behaviour on half-transparent images

I couldn't find a definition in HTML5 for defining browser behaviour on 
image pixels having alpha != 1.0.

I believe there is a need to define a threshold level as of when a pixel is 
to be regarded as "existent", particularly for hyperlink action or similar.

Cheers,
Axel 

Received on Tuesday, 23 July 2013 15:40:28 UTC