Render play image over existing image in objective c - objective-c

Question

I have collection view with some videos and images
Using AVFoundation able to capture video from iPhone and generated thumbnail using AVAssetImageGenerator. When shown in gallery image should distinguish it's of video thumbnail. So i need to transform exact image by drawing video symbol(like play icon) over it.
Is it possible?

Answer 1

You could use CoreGraphics to edit the image.
First, create a UIImage with the image you would like to edit. Then, do something like this:
UIImage *oldThumbnail; //set this to the original thumbnail image
UIGraphicsBeginImageContext(oldThumbnail.size);
[oldThumbnail drawInRect:CGRectMake(0, 0, oldThumbnail.size.width, oldThumbnail.size.height)];
/*Now there are two ways to draw the play symbol.
One would be to have a pre-rendered play symbol that you load into a UIImage and draw with drawInRect */
UIImage *playSymbol = [UIImage imageNamed:"PlaySymbol.png"];
CGRect playSymbolRect; //I'll let you figure out calculating where you should draw the play symbol
[playSymbol drawInRect: playSymbolRect];
//The other way would be to draw the play symbol directly using CoreGraphics calls. Start with this:
CGContextRef context = UIGraphicsGetCurrentContext();
//now use CoreGraphics calls. I won't go over it here, butthe second answer to this questionmay be helpful.
//Once you have finished drawing your image, you can put it in a UIImage.
UIImage *newThumbnail = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext(); //make sure you remember to do this :)
Now you can use the newly generated thumbnail in a UIImageView, cache it so you don't need to re-render it every time, etc.

Answer 2

This should work (you may have to play with positions and sizes):
-(UIImage*)drawPlayButton:(UIImage*)image
{
UIImage *playButton = [UIImage imageNamed:#"playbutton.png"];
UIGraphicsBeginImageContext(image.size);
[image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
[playButton drawInRect:CGRectMake(image.size.width/2-playButton.size.width/2, image.size.height/2-playButton.size.height/2, playButton.size.width, playButton.size.height)];
UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}