RxExtensionMVVM.swift

import UIKit
import RxCocoa
import RxSwift

extension Reactive where Base: UIImageView {

	func image(withDuration: TimeInterval) -> Binder<UIImage?> {
		return Binder(base) { imageView, image in

			// needed to avoid "Value of type 'UIView' has no member 'image'"
			let baseImageView = imageView

			UIView.transition(with: imageView,
							  duration: withDuration,
							  options: .transitionCrossDissolve,
							  animations: { baseImageView.image = image },
							  completion: nil)
		}
	}
}