gistfile1.swift

class StartViewController : UIViewController {

    private var contextQueue_:dispatch_queue_t? = nil
    private var originalImage:UIImage?

    @IBOutlet weak var imageView: UIImageView!
    
    @IBAction func convert(sender: AnyObject) {
        applyFilter()
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        originalImage = imageView.image
        contextQueue_ = dispatch_queue_create("ly.img.filterPreviewQueue", DISPATCH_QUEUE_SERIAL)
    }
    
    func applyFilter() {
        
        var image = self.originalImage!
        dispatch_async(contextQueue_!, {
            autoreleasepool {
            
                var type = IMGLYFilterType(rawValue: Int.random(1...10))!
                //type = IMGLYFilterType.Mono3200
                
                var actualFilter:CIFilter? = IMGLYInstanceFactory.sharedInstance.effectFilterWithType(type)
                var filteredImage:UIImage? = IMGLYPhotoProcessor.processWithUIImage(image, filters: [actualFilter!])
                var text = actualFilter!.displayName
                actualFilter = nil
                dispatch_async(dispatch_get_main_queue(), {
                    self.imageView.image = filteredImage!
                    filteredImage = nil
                })
            }
        })
        
    }
}


extension Int
{
    static func random(range: Range<Int> ) -> Int
    {
        var offset = 0
        
        if range.startIndex < 0   // allow negative ranges
        {
            offset = abs(range.startIndex)
        }
        
        let mini = UInt32(range.startIndex + offset)
        let maxi = UInt32(range.endIndex   + offset)
        
        return Int(mini + arc4random_uniform(maxi - mini)) - offset
    }
}