HelloOpenCV.scala

package net.ladstatt.apps

import java.io.File

import org.opencv.core.Core
import org.opencv.core.MatOfRect
import org.opencv.core.Point
import org.opencv.core.Scalar
import org.opencv.highgui.Highgui
import org.opencv.objdetect.CascadeClassifier

/**
 * Scala version of the introductory tutorial on opencv.org
 */
object HelloOpenCV {
  
  System.load(new File("/opt/local/share/OpenCV/java/libopencv_java244.dylib").getAbsolutePath())
  
  def main(args: Array[String]): Unit = {
    new DetectFaceDemo().run()
  }
}

class DetectFaceDemo {
  def run(): Unit = {
    println("\nRunning DetectFaceDemo")

    // Create a face detector from the cascade file in the resources
    // directory.
    val faceDetector = new CascadeClassifier(getClass().getResource("/lbpcascade_frontalface.xml").getPath())
    val image = Highgui.imread(getClass().getResource("/person.png").getPath())

    // Detect faces in the image.
    // MatOfRect is a special container class for Rect.
    val faceDetections = new MatOfRect()
    faceDetector.detectMultiScale(image, faceDetections)

    println("Detected %s faces".format(faceDetections.toArray().length))

    // Draw a bounding box around each face.
    for (rect <- faceDetections.toArray()) {
      Core.rectangle(image, new Point(rect.x, rect.y), new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(0, 255, 0))
    }

    // Save the visualized detection.
    val filename = "faceDetection.png"
    println(String.format("Writing %s", filename))
    Highgui.imwrite(filename, image)
  }
}