Overlay image on the another image

run.swift

extension UIImage{
    func merge(mergewith: UIImage) -> UIImage {
        
        UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
        
        let actualArea = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        
        let ratioMerge: Double = Double(mergewith.size.height / mergewith.size.width)
        let widthMerge = size.height / ratioMerge
        let mergeX = (size.width / 2) - (widthMerge / 2)
        
        let mergeArea = CGRect(x: mergeX, y: 0, width: widthMerge, height: size.height)
        
        self.draw(in: actualArea)
        mergewith.draw(in: mergeArea)
        let merged = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return merged
    }
}