AspectFill

UIImage.swift

    static func getAspectFillMultiplier(originalSize: CGSize, desirableSize: CGSize) -> CGFloat {
        let heightDiff = desirableSize.height - originalSize.height
        let widthDiff = desirableSize.width - originalSize.width
        var multiplier: CGFloat!
        
        if abs(heightDiff) > abs(widthDiff) {
            multiplier = 1 + heightDiff / originalSize.height
        } else {
            multiplier = 1 + widthDiff / originalSize.width
        }

        return multiplier
    }