GetIfImageHasTransparentBackground.swift

 func getIfImageHasTransparentBackground(image: NSImage) -> Bool {
        var hasTransparentBackground : Bool = false
        let cgImage = image.cgImage
        let context = createARGBBitmapContextFromImage(cgImage: cgImage!)
        let height = cgImage!.height
        let width = cgImage!.width
        
        let rect: CGRect = CGRect(x: 0, y: 0, width: CGFloat(width), height: CGFloat(height))
        context?.draw(cgImage!, in: rect)
        
        let pixelData = image.cgImage!.dataProvider!.data
        let data: UnsafePointer<UInt8> = CFDataGetBytePtr(pixelData)
     
        //Filter through data and look for non-transparent pixels.
        for y in 0..<height {
            for x in 0..<width {
                let pixelIndex = (width * y + x) * 4 /* 4 for A, R, G, B */
                
                if data[Int(pixelIndex)] != 0 { //Alpha value is not zero pixel is not transparent.
                   hasTransparentBackground = false
                    return hasTransparentBackground
                } else {
                    hasTransparentBackground = true
                    return hasTransparentBackground
                }
            }
        }
        
       return hasTransparentBackground
    }
    
    private func createARGBBitmapContextFromImage(cgImage: CGImage) -> CGContext? {
        
        let width = cgImage.width
        let height = cgImage.height
        
        let bitmapBytesPerRow = width * 4
        let bitmapByteCount = bitmapBytesPerRow * height
        
        let colorSpace = CGColorSpaceCreateDeviceRGB()
        /*if colorSpace == nil {
            return nil
        }*/
        
        let bitmapData = malloc(bitmapByteCount)
        if bitmapData == nil {
            return nil
        }
        
        let context = CGContext (data: bitmapData, width: width, height: height, bitsPerComponent: 8, bytesPerRow: bitmapBytesPerRow, space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedFirst.rawValue)
        
        return context
    }