int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

//	NSImage *theImage = [[NSImage alloc] initByReferencingFile:@"/Users/markusca/Desktop/r-big.tiff"];
	NSImage *theImage = [[NSImage alloc] initByReferencingFile:@"/Users/markusca/Desktop/Picture1.png"];
//	NSImage *theImage = [[NSImage alloc] initByReferencingFile:@"/Users/markusca/Desktop/5x5.tif"];
	
	NSBitmapImageRep *imageRep = (NSBitmapImageRep *)[theImage bestRepresentationForDevice:nil];

	int imageWidth = [imageRep pixelsWide];
    int imageHeight = [imageRep pixelsHigh];
	NSMutableSet *mySet = [[NSMutableSet alloc] initWithCapacity:(imageWidth*imageHeight) *.5]; 
	
	NSTimeInterval startTime = [NSDate timeIntervalSinceReferenceDate];
	unsigned short height, width;
	
	for (height = 0; height < imageHeight; height++) {
		for (width = 0; width < imageWidth; width++) {
			//[mySet addObject:[imageRep colorAtX:width y:height]];
		}
	}
	
	NSTimeInterval endTime = [NSDate timeIntervalSinceReferenceDate];
	NSLog(@"Size of image is %i x %i (%i pixels)", imageWidth, imageHeight, (imageHeight * imageWidth));	
	NSLog(@"Time to get all values was %f", (endTime - startTime));
	NSLog(@"The Set size is %i", [mySet count]);
    [pool drain];
    return 0;
}

         NSImage *theImage = [[[NSImage alloc] initWithContentsOfFile:[openPanel filename]] autorelease];
        
         NSBitmapImageRep *imageRep = (NSBitmapImageRep *)[theImage bestRepresentationForDevice:nil];
        
         NSSize size = imageRep.size;
         NSLog(@"{%d, %d}, %d", [imageRep pixelsWide], [imageRep pixelsHigh], [imageRep pixelsWide] * [imageRep pixelsHigh]);
        
         int imageWidth = [imageRep pixelsWide];
         int imageHeight = [imageRep pixelsHigh];
         CFMutableSetRef mySet = CFSetCreateMutable(NULL, (imageWidth*imageHeight) *.5, NULL); 
        
         NSTimeInterval startTime = [NSDate timeIntervalSinceReferenceDate];
         unsigned short height, width;
        
         for (height = 0; height < imageHeight; height++)
                  for (width = 0; width < imageWidth; width++)
                           CFSetAddValue(mySet, [imageRep colorAtX:width y:height]);
        
         NSTimeInterval endTime = [NSDate timeIntervalSinceReferenceDate];
         NSLog(@"time : %f", endTime - startTime);