Re: Custom Composite Operators?
Re: Custom Composite Operators?
- Subject: Re: Custom Composite Operators?
- From: Darrin Cardani <email@hidden>
- Date: Sun, 1 Aug 2004 18:56:45 -0500
At 3:16 PM -0700 8/1/04, "Joseph M Striedl" <email@hidden> wrote:
Is there a way to define custom Composite Operators? (Such as the exisiting
composite operators of CompositeSourceOver, CompositePlusDarker,
CompositePlus Lighter,etc.)
I don't know of any way other than putting the 2 source images into a
bitmap context and combining them pixel by pixel.
I am hoping to integrate into my app the ability to mimic some
Photoshop-esque layering techniques. (such as Hard Light and Soft Light) but
would need more control over the Composite Operators than I currently have.
I am planning on releasing some open source that implements all of
the Photoshop blend modes. I don't have an ETA at the moment on when
it will be ready, however.
As a side note, I have tried setting up a 'for' loop to go through each
pixel of the image and apply a custom equation to the components, but that
takes a long time compared to the Composite Operators, especially given the
size of the images I am working with. (around 31" x 21" @ 200 dpi...about
26M pixels)
Well, you can always profile with Shark to see where the slowdown is
and try to improve the speed. Photoshop does it the way you did it,
and it's pretty fast, so it's possible to do it quickly. Altivec is
your friend here.
Darrin
--
Darrin Cardani - email@hidden
President, Buena Software, Inc.
<
http://www.buena.com/>
Video, Image and Audio Processing Development
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