FlipImageVertically.swift

let image = UIImage(named: "images.jpeg")!

UIGraphicsBeginImageContextWithOptions(image.size, false, 1.0)
var context = UIGraphicsGetCurrentContext()

//move and invert canvas by scaling
CGContextTranslateCTM(context, image.size.width, 0)
CGContextScaleCTM(context, -1, 1)

image.drawInRect(CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))

// move back and reinvert
CGContextScaleCTM(context, 1, 1)
CGContextTranslateCTM(context, -image.size.width, 0)

let flippedImg = UIGraphicsGetImageFromCurrentImageContext()

UIGraphicsEndImageContext()