On 03/12/2008, at 5:34 PM, Jean-Nicolas Jolivet wrote:
Hmm I just found an older post that mentions a big memory leak
problem when drawing CIImage offscreen.... I guess I'll have to do
this differently...
Ah, you've just reminded me. There is a major leak in drawing CIImage
offscreen but you can work around it by rendering to a CGImageRef in
the context of the current window.
Here's the code:
//theImage is an existing NSImage
CIImage *outputImage = [CIImage imageWithData:[theImage
TIFFRepresentation]];
//to draw the image processed by Core Image, we need to draw into an
on-screen graphics context
//this works around a bug in CIImage where drawing in off-screen
graphics contexts causes a huge memory leak
//get the current window's graphics context so that we have an on-
screen context
//usually we would use any view's window but generically you can just
ask for the main window
CIContext *ciContext = [[[NSApp mainWindow] graphicsContext] CIContext];
if(ciContext == nil)
{
NSLog(@"The CIContext of the main window could not be accessed.
Bailing out of the image creation process.");
return;
}
CGAffineTransform transform;
transform = CGAffineTransformMakeTranslation(0.0,[outputImage
extent].size.height);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
outputImage = [outputImage imageByApplyingTransform:transform];
//render the CIIimage into a CGImageRef in the on-screen context
CGImageRef cgImage = [ciContext createCGImage:outputImage fromRect:
[outputImage extent]];
// Draw the CGImageRef into the current context
if (cgImage != NULL)
{
CGContextDrawImage ([[NSGraphicsContext currentContext]
graphicsPort], [outputImage extent], cgImage);
CGImageRelease (cgImage);
}
--
Rob Keniger
_______________________________________________
Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to [EMAIL PROTECTED]
