Re: Transparency attribute in Bitmap class

Andreas Kraft (kraft@fokus.gmd.de)
Tue, 3 Feb 1998 15:35:56 +0100 (MET)

Emmanuel,

On Tue, 3 Feb 1998, Emmanuel BEUQUE wrote:

> À (At) 16:04 +0100 2/02/98, Andreas Kraft écrivait (wrote) :

> I have found incredible that the dropOutColour attribute that was in DIS
> has simply disappeared in IS. This feature is so widely used in the TV
> world that this big loss always make authors angry.

I aggree with Markku and Kei, most not-lossy image formats bring their own
palette and transparency definitions.

> I'm not sure that 54.4 takes care of a contentData that would specify some
> pixels as to be transparent, even if the MHEG transparency attribute is 0%.
>
> Moreover, (I don't know if it was the sense of the question from Guido),
> what would be the rules if the content data itself include some
> transparency information such as an alpha layer. I think that both ratios
> (MHEG uniform transparency and contentData alpha layer pixel transparency
> should be multiplied to get the final pixel transparency.

Please correct me if I am wrong, but I think that an authoring process is
something an author has more or less full control over. If s/he authors a
wrong transparency combination then the result is of course somehow not what
was desired. I know, there are some occasions where this control does not
exists.

Regards,

Andreas

--
  o  _     Andreas Kraft
 (\_|_)      GMD FOKUS, kraft@fokus.gmd.de, +49 30 3463-7232
 T> ] [        The sky is the limit