How to find the pixel location in original image in ios

Question

I have an image with size 480x360 and am displaying in UIImageview with frame (0, 0, 320, 568) with aspectfill.

W

Answer 1

You just calculate the proportions and apply them to touch location point.

CGFloat _x = imageView.image.size.width / imageView.frame.size.width;
CGFloat _y = imageView.image.size.height / imageView.frame.size.height;

//assuming p - is CGPoint received from Touch event
CGPoint locationInImageView = CGPointMake(p.x * _x, p.y * _y);

Answer 2

Finding the pixel location of the touch in Swift:

guard let image = imageView.image else {
    return
}

let x = image.size.width / imageView.frame.size.width
let y = image.size.height / imageView..frame.size.height

// Assuming touchLocation is CGPoint received from Touch event
var touchLocation: CGPoint
let locationInImageView = CGPoint(x: touchLocation.x * x, y: touchLocation.y * y);