I have a beautiful CGImageRef context, which I created the whole day to get alpha values ;)
It's defined like that:
CGContextRef context = CGBitmapContextCreate (bitmapData, pixWidth, pixHeiht 8, pixWidth, NULL, kCGImageAlphaOnly);
So for my understanding, that context represents somehow my image. But "virtually", non-visible somewhere in memory.
Can I stuff that in an UIImageView or draw that directly to the screen? I guess that alpha would be converted to grayscale or something like that.
You can create a UIImage
by calling:
+ (UIImage *)imageWithCGImage:(CGImageRef)cgImage
and then draw the UIImage
using:
- (void)drawAtPoint:(CGPoint)point
Go look at CGBitmapContextCreateImage()
, that can give you a CGImageRef from your bitmap context. You can then draw that using the CGContext... functions or make a UIImage using +[UIImage imageWithCGImage:]
.
CGSize size = ...;
UIGraphicsBeginImageContext(size);
...
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
...
CGPoint pt = ...;
[img drawAtPoint:pt];
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