Ex4TrackingFeatures.scala

/*
 * Copyright (c) 2011-2014 Jarek Sacha. All Rights Reserved.
 *
 * Author's e-mail: jpsacha at gmail.com
 */

package opencv_cookbook.chapter11

import java.io.File


/** The example for section "Tracking feature points in video" in Chapter 10, page 266.
  *
  * Tracking is implemented in class `FeatureTracker`.
  *
  * Unlike in the C++ implementation, we do not need to pass `FeatureTracker` object as a parameter to `VideoProcessor`.
  * We only need to pass to `VideoProcessor` method `process` with its "context".
  * This simplifies implementation of `VideoProcessor`.
  * Scala can treat `process` as a "closure", that is method `process` will have access to all local member variables
  * in class `FeatureTracker`.
  */
object Ex4TrackingFeatures extends App {

  // Use command line path, if provided
  val inputFile = args
    .headOption
    .map(new File(_))
    .getOrElse(new File("data/bike.avi"))

  // Open video file
  println("Processing video file: " + inputFile.getCanonicalPath)

  // Feature tracker
  val tracker = new FeatureTracker()


  // Create video processor instance
  val processor = new VideoProcessor()
  processor.input = inputFile.getCanonicalPath
  // Declare a window to display input and output the video
  processor.displayInput = "Input Video"
  processor.displayOutput = "Output Video"
  // Play the video at the original frame rate
  processor.delay = math.round(1000d / processor.frameRate)
  // Set the frame processor callback function (pass FeatureTracker `process` method as a closure)
  processor.frameProcessor = tracker.process

  // Start the process
  processor.run()


  println("Done.")
}