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[qwerty2k]

//Load in the image we want to analyse
	UIImage *c = [UIImage imageNamed:@"test.jpg"];
	
	//Convert image to format we can look at
	CGImageRef inImage = CGImageRetain(c.CGImage);          
    CGContextRef ctx;  
	
	//Get the pixel data from the image
	CFDataRef m_DataRef;  
	m_DataRef = CGDataProviderCopyData(CGImageGetDataProvider(inImage));  
	UInt8 * m_PixelBuf = (UInt8 *) CFDataGetBytePtr(m_DataRef);  
    //    Byte tmpByte;  
	int length = CFDataGetLength(m_DataRef);  
	//NSLog(@"len %d", length);  
	int bytesPerPixel = 4;
	
	int imageWidth = CGImageGetWidth(inImage);
	int imageHeight = CGImageGetHeight(inImage);

        int x = 25;
        int y = 25;

int offset = 4*((imageWidth*round(Y))+round(X))
	NSLog(@"offset:%i", offset);
	m_PixelBuf[offset+1] = 255;
	m_PixelBuf[offset+2] = 1;
	m_PixelBuf[offset+3] = 1;

	//Create an image from the pixel data
	ctx = CGBitmapContextCreate(m_PixelBuf,  
								CGImageGetWidth( inImage ),  
								CGImageGetHeight( inImage ),  
								8,  
								CGImageGetBytesPerRow( inImage ),  
								CGImageGetColorSpace( inImage ),  
								kCGImageAlphaPremultipliedFirst );  
	
	
	CGImageRef imageRef = CGBitmapContextCreateImage (ctx);  
	UIImage* rawImage = [UIImage imageWithCGImage:imageRef];  
	
	CGContextRelease(ctx);  
	
	//Set the UIImage to the new image data
    testPic2.image = rawImage;

thats a rough outline of the code im using, picture im testing on is a 50px by 50px pixel just as a test yet trying to get x,y of 25,25 doesn't yield the pixel in the dead center of the image