ios - How to add an overlay layer to a UIImageView but not on the transparent part of the image? -


i have uiimageview:

self.princessimageview.image = uiimage(named: "princess")!

enter image description here

now trying add coloured layer alpha of 0.3 on image. tried this: 

let overlayview: uiview = uiview(frame: cgrect(x: 0,                                                y: 0,                                                width: self.princessimageview.frame.size.width,                                                height: self.princessimageview.frame.size.height)) overlayview.backgroundcolor = uicolor.blue.withalphacomponent(0.3) self.princessimageview.addsubview(overlayview)

but i'm getting result.

enter image description here

i understand of course it's because i'm setting overlay on whole view. there way can set overlay on non-transparent part of image ?

thanks help.

you need play blending modes that.

apple documentation : link

some relevant stuff might : link1 link2


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