WebcamMotionDetectorAlgorithm.java

package com.github.sarxos.webcam;

import java.awt.Point;
import java.awt.image.BufferedImage;
import java.util.ArrayList;


/**
 * Implementation of this interface is responsible for decision whether the
 * difference between two images represents movement or not. Instance may
 * specified as parameter of WebcamMotionDetector constructor, otherwise
 * WebcamMotionDetectorDefaultAlgorithm is used.
 */
public interface WebcamMotionDetectorAlgorithm {

	/**
	 * WebcamMotionDetector calls this method for each image used as parameter
	 * of the method {@link #detect(BufferedImage, BufferedImage)}.
	 * Implementation may transform the original image and prepare it for
	 * comparison of two images.
	 * May return the same instance if no there is no need to transform.
	 * 
	 * @param original image
	 * @return modified image
	 */
	BufferedImage prepareImage(BufferedImage original);

	/**
	 * Detects motion by comparison of the two specified images content.
	 * {@link #prepareImage(BufferedImage)} method was called for both specified images.
	 * 
	 * @param previousModified 
	 * @param currentModified
	 * @return If the motion was detected returns true, otherwise returns false
	 */
	boolean detect(BufferedImage previousModified, BufferedImage currentModified);
	
	/**
	 * Get motion center of gravity. When no motion is detected this value
	 * points to the image center.
	 * May return null before the first movement check.
	 *
	 * @return Center of gravity point
	 */
	Point getCog();
	
	/**
	 * Get percentage fraction of image covered by motion. 0 means no motion on
	 * image and 100 means full image covered by spontaneous motion.
	 *
	 * @return Return percentage image fraction covered by motion
	 */
	double getArea();

    /**
     * Set the minimum range between each point detected
     * @param i the range to set
     */
    void setPointRange(int i);

    /**
     * Set the max amount of points that can be detected at one time
     * @param i The amount of points that can be detected
     */
    void setMaxPoints(int i);


    /**
     * Get the current minimum range between each point
     * @return The current range
     */
    int getPointRange();

    /**
     * Get the current max amount of points that can be detected at one time
     * @return
     */
    int getMaxPoints();


    /**
     * Returns the currently stored points that have been detected
     * @return The current points
     */
    ArrayList<Point> getPoints();
}