zxing ios4.m

- (void)takePicture:(NSTimer*)theTimer {
  CGImageRef capture = UIGetScreenImage();
  CGRect cropRect = [overlayView cropRect];
  if (oneDMode) {
    // let's just give the decoder a vertical band right above the red line
    cropRect.origin.x = cropRect.origin.x + (cropRect.size.width / 2) - (ONE_D_BAND_HEIGHT + 1);
    cropRect.size.width = ONE_D_BAND_HEIGHT;
    // do a rotate
    CGImageRef croppedImg = CGImageCreateWithImageInRect(capture, cropRect);
    capture = [self CGImageRotated90:croppedImg];
    capture = [self CGImageRotated180:capture];
    CGImageRelease(croppedImg);
    cropRect.origin.x = 0.0;
    cropRect.origin.y = 0.0;
    cropRect.size.width = CGImageGetWidth(capture);
    cropRect.size.height = CGImageGetHeight(capture);
  } 
	
	UIImage *decodeImage = nil;
	
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_4_0
	if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] && 
		 [UIScreen mainScreen].scale > 1.0)
	{
		UIImage *image = [[[UIImage alloc] initWithCGImage:capture scale:1.0 orientation:UIImageOrientationUp] autorelease];
		UIGraphicsBeginImageContextWithOptions(CGSizeMake(320, 480), NO, 1.0);
		[image drawInRect:CGRectMake(0, 0, 320, 480)];
		decodeImage = UIGraphicsGetImageFromCurrentImageContext();
		UIGraphicsEndImageContext();
	}
	else
	{
#endif		
		CGImageRef newImage = CGImageCreateWithImageInRect(capture, cropRect);
		decodeImage = [[[UIImage alloc] initWithCGImage:newImage] autorelease];
		CGImageRelease(newImage);
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_4_0
	}
#endif
	
	Decoder *d = [[Decoder alloc] init];
	d.readers = readers;
	d.delegate = self;
	[d decodeImage:decodeImage cropRect:cropRect];
        CGImageRelease(capture);
}

this is a patch for making zxing work with ios4 devices and retina display