UIImage Performance

benchmark.swift

extension DispatchTimeInterval {
	func toDouble() -> Double? {
		var result: Double? = 0
		
		switch self {
		case .seconds(let value):
			result = Double(value)
		case .milliseconds(let value):
			result = Double(value)*0.001
		case .microseconds(let value):
			result = Double(value)*0.000001
		case .nanoseconds(let value):
			result = Double(value)*0.000000001
			
		case .never:
			result = nil
		}
		
		return result
	}
}

import UIKit

let path = Bundle.main.path(forResource: "dog", ofType: "png")!

let startTime = DispatchTime.now()

// On my laptop, takes around 120ms.
let image = UIKit.UIImage.init(contentsOfFile: path)!

let endTime = DispatchTime.now()

image.size

let duration = startTime.distance(to: endTime).toDouble()!

print("Time to evaluate: \(duration*1000.0)ms")