import UIKit
import Accelerate

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let imageForConversion = #imageLiteral(resourceName: "InputImage")
        let img: CGImage = imageForConversion.cgImage!
        let imgProvider: CGDataProvider = img.dataProvider!
        let imgBitmapData: CFData = imgProvider.data!
        var imgBuffer = vImage_Buffer(data: UnsafeMutableRawPointer(mutating: CFDataGetBytePtr(imgBitmapData)), height: vImagePixelCount(img.height), width: vImagePixelCount(img.width), rowBytes: img.bytesPerRow)

        for i in 0...img.height {
            for j in 0...img.width {
                let test = imgBuffer.data.load(fromByteOffset: (i * img.width + j) * 4, as: UInt32.self)

                let r = Float((test >> 16) & 255) / 256
                let g = Float((test >> 8) & 255) / 256
                let b = Float(test & 255) / 256
                let intensity = 0.114 * r + 0.587 * g + 0.299 * b

                print(intensity > 0.5 ? "1" : "0", terminator: "")
            }
            print("")
        }
    }

}