Re: speeding up jpeg writing to disk from CIImage

Subject: Re: speeding up jpeg writing to disk from CIImage
From: Frank Doepke <email@hidden>
Date: Wed, 16 Nov 2005 13:41:51 -0800
Delivered-to: email@hidden
Delivered-to: email@hidden

Have you looked at using ImageIO to write out the file? I haven't compared the numbers but it could be a little bit more efficient. Check out the CI Annotation sample code.

Frank

On Nov 16, 2005, at 12:54 PM, Samuel DeVore wrote:

So I am processing some large ( >30Meg) tif files by applying some filters and then writing out to disk as jpegs and it seems to be pretty slow. I am using the following to do the writing (resultImage is the CIImage after the filters) Are there any things I can try to squeeze a little more performance out of this?

theBitMapToBeSaved = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:NULL pixelsWide:newSize.width pixelsHigh:newSize.height bitsPerSample:kBitsPerSample samplesPerPixel:kSamplesPerPixel hasAlpha:YES isPlanar:NO colorSpaceName:NSCalibratedRGBColorSpace bytesPerRow:0 bitsPerPixel: 0];

NSGraphicsContext *nsContext = [NSGraphicsContext graphicsContextWithBitmapImageRep:theBitMapToBeSaved];

[[nsContext CIContext] drawImage:[self resultImage] atPoint:imageDestinationRect.origin fromRect:[[self resultImage] extent]];

theFileSaveDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithFloat: ([jpegQuality floatValue] / 100.0)], NSImageCompressionFactor, nil];

[[theBitMapToBeSaved representationUsingType:NSJPEGFileType properties:theFileSaveDictionary] writeToURL:url atomically:YES];
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References:  
  >speeding up jpeg writing to disk from CIImage (From: Samuel DeVore <email@hidden>)




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References:
	>speeding up jpeg writing to disk from CIImage (From: Samuel DeVore <email@hidden>)