Re: Alpha-channeled images fade to black?
Re: Alpha-channeled images fade to black?
- Subject: Re: Alpha-channeled images fade to black?
- From: John Stiles <email@hidden>
- Date: Thu, 18 Mar 2004 14:44:47 -0800
This is known as "pre-multiplied alpha." NSImage uses this as a way to
speed up software-based alpha effects.
I'm sure there's a way to make OpenGL do the right thing with
premultiplied alpha, but I couldn't tell you how :) The OpenGL list
would know.
On Mar 18, 2004, at 12:02 PM, Jonathan del Strother wrote:
Hi,
I'm loading .tiff files through NSImage into an OpenGL texture. Where
the texture is semi-transparent, it's much darker than the opaque
areas, as if the image color is getting multiplied by the color of the
alpha channel, in addition to the alpha channel providing the
transparency.
Anyone know if this is a Photoshop, NSImage, or OpenGL problem? How
can I fix it?
Thanks,
Jon
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