Re: Avoiding Cached ImageReps?
Re: Avoiding Cached ImageReps?
- Subject: Re: Avoiding Cached ImageReps?
- From: Tom Waters <email@hidden>
- Date: Sun, 7 Jul 2002 15:02:13 -0700
you can get it back...
- (NSBitmapImageRep *)bitmapRep
{
NSBitmapImageRep *rep = [[self representations] objectAtIndex:0];
if (![rep isKindOfClass:[NSBitmapImageRep class]]) {
id birep = [NSBitmapImageRep imageRepWith
Data:[self
TIFFRepresentation]];
[self removeRepresentation:rep];
[self addRepresentation:birep];
rep = birep;
}
return rep;
}
i wrote this category on NSImage to say "get me the bits back and
replace that pesky cachedimagerep with it".
might not be exactly right for your application, but it shows you how to
use TIFFRepresentation, which is what you are looking for...
On Sunday, July 7, 2002, at 02:46 PM, Fritz Anderson wrote:
I'm working on a simple bitmap-analysis program. The user pulls in
images though NSImage and then selecting parts of the images for
further work. The application attempts to obtain the underlying bitmap
data through NSBitmapImageRep.
It seems that as soon as I lock focus on the image, the contained
representation becomes an NSCachedImageRep, and the underlying bitmap
is forever out of my reach. This means I can't use much of Cocoa (or at
least much of NSImage and its cousins) to do the convenience and
human-interface work leading up to my bitmap-level image processing.
Now, I recognize that there are good performance reasons (which Apple
has promised will soon become even better) to want to turn buffers over
to hardware. I also know that much (_but not all_) low-level graphics
work is unsuited to Cocoa-level programming.
It just seems to me that once I entrust data to Cocoa, I ought to be
able to trust Cocoa to give me my data back. (I swear I'm not trying to
generate unauthorized re-dithers of trademarked or copyrighted mice, if
that's the issue.)
Is there some way to achieve this? Or, if Cocoa is not the
higher-than-POSIX level for reading, presenting, and moving images, can
someone point me in the right direction in, for instance, Core Graphics?
-- F
[Apologies if this comes as a re-send; I was a bit confused about my
subscription.]
--
Fritz Anderson - Consulting Programmer - Chicago, IL
Mail: <email@hidden>
Risumi: <http://resume.manoverboard.org>
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