Resizing UIImage keeping aspect ratio

UIImage+resized.swift

import UIKit

extension UIImage {
    func resized(maxSize: CGFloat) -> UIImage? {
        let scale: CGFloat
        if size.width > size.height {
            scale = maxSize / size.width
        }
        else {
            scale = maxSize / size.height
        }
        
        let newWidth = size.width * scale
        let newHeight = size.height * scale
        UIGraphicsBeginImageContext(CGSize(width: newWidth, height: newHeight))
        draw(in: CGRect(x: 0, y: 0, width: newWidth, height: newHeight))
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage
    }
}