Swift: UIGraphicsBeginImageContextWithOptions scale factor set to 0 but not applied

I used to resize an image with the following code and it used to work just fine regarding the scale factor. Now with Swift 3 I can't figure out why the scale factor is not taken into account. The image is resized but the scale factor not applied. Do you know why? let layer = [login to view URL] UIGraphicsBeginImageContextWithOptions([login to view URL], true, 0) [login to view URL](in: UIGraphicsGetCurrentContext()!) let scaledImage = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() print("SCALED IMAGE SIZE IS (scaledImage!.size)") print(scaledImage!.scale) For example if I take a screenshot on iPhone 5 the image size will be 320*568. I used to get 640*1136 with exact same code.. What can cause the scale factor not to be applied? When I print the scale of the image it would print 1, 2 or 3 based on the device resolution but will not be applied to the image taken from the context.