Re: Making an image NSCalibratedWhiteColorSpace
Re: Making an image NSCalibratedWhiteColorSpace
- Subject: Re: Making an image NSCalibratedWhiteColorSpace
- From: Marcel Weiher <email@hidden>
- Date: Thu, 15 Nov 2001 00:56:21 +0100
On Thursday, November 15, 2001, at 12:25 AM, Nat! wrote:
On Mittwoch, November 14, 2001, at 11:58 Uhr, Andrew Platzer wrote:
On Tuesday, November 13, 2001, at 06:51 , Gideon King wrote:
To create the image, I need to do some drawing, so I use an image
with and NSCustomImageRep to do the drawing. I tell that image
rep to be NSCalibratedWhiteColorSpace. I then lock focus on the
image and use initWithFocusedViewRect: to get the bitmap data.
This always returns an image rep with RGBA color in
NSCalibratedRGBColorSpace. If I then set it to
NSCalibratedWhiteColorSpace, it doesn't do any conversion for
me - just leaves it as 4 samples per pixel (RGBA).
Will I need to do the conversion manually, or is there some way
that will allow me to get a grayscale alpha image directly?
initWithFocusedViewRect: reads from the window's backing store
buffer and that is always RGB or RGBA. This is true even in images
which you lock focus on since it creates an offscreen window to
record the bits.
You will have to do the conversion manually.
Andrew
Are there any plans that AppKit can do this for us ? It seems that
the machinery at least partly (-> RGB, RGBA) must already be in
place.
In theory, it should be possible to limit the depth of the window's
backing store, and there are even some NSWindow methods for this.
However, these methods don't seem to have any effect.
Marcel
--
Marcel Weiher Metaobject Software Technologies
email@hidden www.metaobject.com
Metaprogramming for the Graphic Arts. HOM, IDEAs, MetaAd etc.