UIImage fix orientation ( rotate pixel rather than relying on exif )

UIImage+Orientation.swift

//
//  UIImage+Orientation.swift
//  DrCloudPatient
//
//  Created by DW78 on 8/21/15.
//  Copyright (c) 2015 DW78. All rights reserved.
//
// swift 3.2 

import UIKit

extension UIImage {
    
 extension UIImage {
    
    func fixOrientation() -> UIImage {
        
        // No-op if the orientation is already correct
        if ( self.imageOrientation == UIImageOrientation.up ) {
            return UIImage(cgImage: self.cgImage!, scale: scale, orientation: imageOrientation)
        }
        
        // We need to calculate the proper transformation to make the image upright.
        // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
        var transform: CGAffineTransform = CGAffineTransform.identity
        
        if ( self.imageOrientation == UIImageOrientation.down || self.imageOrientation == UIImageOrientation.downMirrored ) {
            transform = transform.translatedBy(x: self.size.width, y: self.size.height)
            transform = transform.rotated(by: CGFloat(M_PI))
        }
        
        if ( self.imageOrientation == UIImageOrientation.left || self.imageOrientation == UIImageOrientation.leftMirrored ) {
            transform = transform.translatedBy(x: self.size.width, y: 0)
            transform = transform.rotated(by: CGFloat(M_PI_2))
        }
        
        if ( self.imageOrientation == UIImageOrientation.right || self.imageOrientation == UIImageOrientation.rightMirrored ) {
            transform = transform.translatedBy(x: 0, y: self.size.height);
            transform = transform.rotated(by: CGFloat(-M_PI_2));
        }
        
        if ( self.imageOrientation == UIImageOrientation.upMirrored || self.imageOrientation == UIImageOrientation.downMirrored ) {
            transform = transform.translatedBy(x: self.size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        }
        
        if ( self.imageOrientation == UIImageOrientation.leftMirrored || self.imageOrientation == UIImageOrientation.rightMirrored ) {
            transform = transform.translatedBy(x: self.size.height, y: 0);
            transform = transform.scaledBy(x: -1, y: 1);
        }
        
        // Now we draw the underlying CGImage into a new context, applying the transform
        // calculated above.
        let ctx: CGContext = CGContext(data: nil, width: Int(self.size.width), height: Int(self.size.height),
                                       bitsPerComponent: self.cgImage!.bitsPerComponent, bytesPerRow: 0,
                                       space: self.cgImage!.colorSpace!,
                                       bitmapInfo: self.cgImage!.bitmapInfo.rawValue)!;
        
        ctx.concatenate(transform)
        
        if ( self.imageOrientation == UIImageOrientation.left ||
            self.imageOrientation == UIImageOrientation.leftMirrored ||
            self.imageOrientation == UIImageOrientation.right ||
            self.imageOrientation == UIImageOrientation.rightMirrored ) {
            ctx.draw(self.cgImage!, in: CGRect.init(x: 0,y: 0,width: self.size.height, height: self.size.width))
            //CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.cgImage)
        } else {
            ctx.draw(self.cgImage!, in: CGRect.init(x: 0,y: 0,width: self.size.width, height: self.size.height))
            //ctx.draw(self.cgImage!, in: CGRect(0,0,self.size.width,self.size.height))
            //CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.cgImage)
        }
        
        // And now we just create a new UIImage from the drawing context and return it
        return UIImage(cgImage: ctx.makeImage()!)
    }
}