Generation UIImage with first letters of two first words

UIImageLettersExtenstion.swift

import UIKit

extension UIImage {
    class func lettersPhoto(_ input: String,
                            size: CGSize = CGSize(width:100, height:100)) -> UIImage? {
        // Color generation place
        let bgColor = UIColor.black
        let height = size.height/2
        
        let letters:String = {
            let maxChars = 2
            let words = input.split(separator: " ")
            return words[0..<min(maxChars, words.count)].reduce("") { (output, word) -> String in
                guard let char = word.characters.first else { return output }
                return output + String(char).uppercased()
            }
        }()
        
        let attrs = [NSAttributedStringKey.font: UIFont.systemFont(ofSize: height),
                     NSAttributedStringKey.foregroundColor: UIColor.white]
        let stringSize = (letters as NSString).size(withAttributes: attrs)
        
        let rect = CGRect(origin: CGPoint.zero,
                          size: size)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, 1)
        let c = UIGraphicsGetCurrentContext()
        c?.setFillColor(bgColor.cgColor)
        c?.fill(rect)
        
        letters.draw(with: CGRect(origin: CGPoint(x: (size.width - stringSize.width)/2,
                                                  y: (size.height - stringSize.height)/2),
                                  size: stringSize),
                     options: .usesLineFragmentOrigin,
                     attributes: attrs,
                     context: nil)
        let result = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        return result
    }
}