Macruby Face Detection in Mac OS X Lion. Usage: $ macruby face_detector.rb or $ macruby face_detector.rb image_url

face_detector.rb

framework 'Cocoa'

class FaceDetectionDelegate
  attr_accessor :window

  def initWithURL(url)
    case url
    when String
       @photo_url = NSURL.URLWithString(url)
    when NSURL
      @photo_url = url
    else
      raise "The FaceDetectionDelegate class was initiated with an unknown type object"
    end
    self
  end
  
  def applicationDidFinishLaunching(aNotification)
    window.delegate = self
    puts "Fetching and loading the image #{@photo_url.absoluteString}"
    
    source = CGImageSourceCreateWithURL @photo_url, nil
    @cg_image = CGImageSourceCreateImageAtIndex source, 0, nil
    puts "image size: w=#{CGImageGetWidth(@cg_image)}, h=#{CGImageGetHeight(@cg_image)}"

    view = NSView.alloc.initWithFrame CGRectMake(0.0, 0.0, CGImageGetWidth(@cg_image), CGImageGetHeight(@cg_image))
    view.wantsLayer = true
    
    calayer = CALayer.layer
    calayer.frame = view.frame
    calayer.contents = @cg_image
    view.layer.addSublayer calayer
    
    window.setFrame([0.0, 0.0, (CGImageGetWidth(@cg_image)+20), (CGImageGetHeight(@cg_image)+20)], display:true, animate:true)
    
    window.center
    
    window.contentView.wantsLayer = true
    window.contentView.layer.affineTransform = CGAffineTransformMakeScale(1, 1)
    
    window.contentView.addSubview(view)
    
    detect_faces
    window.orderFrontRegardless
  end
  
  def detect_faces
    ciImage = CIImage.imageWithCGImage @cg_image
    
    detectorOptions = {CIDetectorAccuracy: CIDetectorAccuracyHigh }
    detector = CIDetector.detectorOfType "CIDetectorTypeFace", context:nil, options:detectorOptions
    features = detector.featuresInImage(ciImage)
    features.each do |feature|
      face = CALayer.layer
      face.frame = feature.bounds
      face.backgroundColor = CGColorCreateGenericRGB(1, 1, 0, 0.4)
      window.contentView.layer.addSublayer face 
      
      if(feature.hasLeftEyePosition)
        left_eye = CALayer.layer
        left_eye.frame = CGRectMake(0, 0, 15, 15)
        left_eye.backgroundColor = CGColorCreateGenericRGB(0, 0, 1, 0.2)
        left_eye.position = feature.leftEyePosition
        window.contentView.layer.addSublayer left_eye
      end
      
      if(feature.hasRightEyePosition)        
        right_eye = CALayer.layer
        right_eye.frame = CGRectMake(0, 0, 15, 15)
        right_eye.backgroundColor = CGColorCreateGenericRGB(1, 0, 0, 0.2)        
        right_eye.position = feature.rightEyePosition
        window.contentView.layer.addSublayer right_eye
      end
      
      if(feature.hasMouthPosition)
        mouth = CALayer.layer
        mouth.frame = CGRectMake(0, 0, 40, 15)
        mouth.backgroundColor = CGColorCreateGenericRGB(0, 1, 0, 0.2)        
        mouth.position = feature.mouthPosition
        window.contentView.layer.addSublayer mouth
      end
    end
  end

  def windowWillClose(sender); exit(1); end

end

# Create the Application
application = NSApplication.sharedApplication
NSApplication.sharedApplication.activationPolicy = NSApplicationActivationPolicyRegular
application.delegate = FaceDetectionDelegate.alloc.initWithURL(ARGV.shift || "http://merbist.com/wp-content/uploads/2010/03/matz_koichi_matt_aimonetti_sansonetti_jimmy.jpg")

# create the Application Window
frame = [0.0, 0.0, 330, 250]
window = NSWindow.alloc.initWithContentRect frame, 
                                  styleMask: NSTitledWindowMask | NSClosableWindowMask,
                                    backing: NSBackingStoreBuffered,
                                      defer: false

application.delegate.window = window
window.orderOut(nil)
window.display
puts "Starting the app..."
application.run