RSS/Atom feed Twitter
Site is read-only, email is disabled
  1. Chat
  2. Useful links
  3. Polls

Featured content

Combining Porter-Duff operations with Blend Modes?

This discussion is connected to the gimp-developer-list.gnome.org mailing list which is provided by the GIMP developers and not related to gimpusers.com.

This is a read-only list on gimpusers.com so this discussion thread is read-only, too.

2 of 2 messages available
Toggle history

Please log in to manage your subscriptions.
Combining Porter-Duff operations with Blend Modes? Calculemus 13 Jul 11:33
  Combining Porter-Duff operations with Blend Modes? Ville Sokk 13 Jul 16:51
Calculemus
2012-07-13 11:33:50 UTC (over 12 years ago)

Combining Porter-Duff operations with Blend Modes?

Sorry I replied to previous message with this content, but meant to send this
as new topic.

How does GIMP deal with Porter-Duff operations and Blend modes?

Where can I find an example code of this?

Mathematically there is one formula to mix porter-duff and blending into one, but I am interested how is this implemented.

Thanks

Ville Sokk
2012-07-13 16:51:58 UTC (over 12 years ago)

Combining Porter-Duff operations with Blend Modes?

On Fri, Jul 13, 2012 at 2:33 PM, Calculemus wrote:

Sorry I replied to previous message with this content, but meant to send this
as new topic.

How does GIMP deal with Porter-Duff operations and Blend modes?

Where can I find an example code of this?

Mathematically there is one formula to mix porter-duff and blending into one, but I am interested how is this implemented.

Thanks _______________________________________________ gimp-developer-list mailing list
gimp-developer-list@gnome.org
https://mail.gnome.org/mailman/listinfo/gimp-developer-list

The way blending modes are done in GIMP is a hack using 8-bit integers and not a good representation of Porter-Duff operations. Look into GEGL's sources, it even has a Porter-Duff category http://gegl.org/operations.html