org.openimaj.video.processing.motion

Class MotionEstimator

java.lang.Object

org.openimaj.video.Video<T>

org.openimaj.video.processor.VideoProcessor<T>

org.openimaj.video.analyser.VideoAnalyser<FImage>

org.openimaj.video.processing.motion.MotionEstimator

All Implemented Interfaces:

Closeable, AutoCloseable, Iterable<FImage>

Direct Known Subclasses:

GridMotionEstimator

public abstract class MotionEstimator
extends VideoAnalyser<FImage>

A motion estimator will estimate the motion of parts of a video frame. This class includes a set of algorithms for calculating the motion estimation.

This class deals with the buffering of frames from the video which to pass to the motion estimation. The class is abstract and the method estimateMotionField(MotionEstimatorAlgorithm, VideoFrame, VideoFrame[]) must be overridden by an implementing class to provide the field over which the motion estimation will take place. This field may, for example, be a grid or an overlapping grid. This overridden method must also determine the appropriate way to call the motion estimation algorithm while returning a map which maps a point to a displacement vector.

Author:

David Dupplaw (dpd@ecs.soton.ac.uk)

Field Summary

Fields

Modifier and Type	Field and Description
Map<Point2d,Point2d>	motionVectors The estimated motion vectors for the last analysed frame

Constructor Summary

Constructors

Constructor and Description
MotionEstimator(MotionEstimatorAlgorithm alg) Constructor a new motion estimator using the given algorithm.
MotionEstimator(Video<FImage> v, MotionEstimatorAlgorithm alg) Create a chainable motion estimator.

Method Summary

Methods

Modifier and Type	Method and Description
void	analyseFrame(FImage frame) Analyse the given frame and make no changes to the frame.
protected abstract Map<Point2d,Point2d>	estimateMotionField(MotionEstimatorAlgorithm estimator, VideoFrame<FImage> frame, VideoFrame<FImage>[] array) This method needs to be overridden for specific layouts of motion field within the image.
Map<Point2d,Point2d>	getMotionVectors() Return the estimated motion vectors for the last processed frame.

Methods inherited from class org.openimaj.video.analyser.VideoAnalyser

processFrame

Methods inherited from class org.openimaj.video.processor.VideoProcessor

countFrames, getCurrentFrame, getFPS, getHeight, getNextFrame, getTimeStamp, getWidth, hasNextFrame, process, process, processingComplete, reset

Methods inherited from class org.openimaj.video.Video

close, getCurrentFrameIndex, iterator, seek, setCurrentFrameIndex

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

motionVectors

public Map<Point2d,Point2d> motionVectors

The estimated motion vectors for the last analysed frame

Constructor Detail

MotionEstimator

public MotionEstimator(MotionEstimatorAlgorithm alg)

Constructor a new motion estimator using the given algorithm.

Parameters:

alg - The algorithm to use to estimate motion.

MotionEstimator

public MotionEstimator(Video<FImage> v,
               MotionEstimatorAlgorithm alg)

Create a chainable motion estimator.

Parameters:

v - The video to chain to

alg - The algorithm to use to estimate motion

Method Detail

analyseFrame

public void analyseFrame(FImage frame)

Analyse the given frame and make no changes to the frame.

Specified by:

analyseFrame in class VideoAnalyser<FImage>

Parameters:

frame - The video frame to analyse

See Also:

VideoAnalyser.analyseFrame(org.openimaj.image.Image)

getMotionVectors

public Map<Point2d,Point2d> getMotionVectors()

Return the estimated motion vectors for the last processed frame.

Returns:

The estimated motion vectors

estimateMotionField

protected abstract Map<Point2d,Point2d> estimateMotionField(MotionEstimatorAlgorithm estimator,
                                       VideoFrame<FImage> frame,
                                       VideoFrame<FImage>[] array)

This method needs to be overridden for specific layouts of motion field within the image.

Parameters:

frame - The current frame

array - The list of previous frames (based on the estimator)

Returns:

The motion field