RANSACRadialDistortionRobustEstimator.java
/*
* Copyright (C) 2015 Alberto Irurueta Carro (alberto@irurueta.com)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.irurueta.ar.calibration.estimators;
import com.irurueta.ar.calibration.RadialDistortion;
import com.irurueta.geometry.CoordinatesType;
import com.irurueta.geometry.Point2D;
import com.irurueta.geometry.estimators.LockedException;
import com.irurueta.geometry.estimators.NotReadyException;
import com.irurueta.numerical.robust.RANSACRobustEstimator;
import com.irurueta.numerical.robust.RANSACRobustEstimatorListener;
import com.irurueta.numerical.robust.RobustEstimator;
import com.irurueta.numerical.robust.RobustEstimatorException;
import com.irurueta.numerical.robust.RobustEstimatorMethod;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Finds the best radial distortion for provided collections of 2D points using
* RANSAC algorithm
*/
public class RANSACRadialDistortionRobustEstimator extends RadialDistortionRobustEstimator {
/**
* Constant defining default threshold to determine whether points are
* inliers or not.
* By default, 1.0 is considered a good value for cases where measures are
* done on pixels, since typically the minimum resolution is 1 pixel.
*/
public static final double DEFAULT_THRESHOLD = 1.0;
/**
* Minimum value that can be set as threshold.
* Threshold must be strictly greater than 0.0.
*/
public static final double MIN_THRESHOLD = 0.0;
/**
* Threshold to determine whether points are inliers or not when testing
* possible estimation solutions.
* The threshold refers to the amount of error (i.e. distance) a possible
* solution has on a matched pair of points.
*/
private double threshold;
/**
* Constructor.
*/
public RANSACRadialDistortionRobustEstimator() {
super();
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor.
*
* @param listener listener to be notified of events such as when
* estimation starts, ends or its progress significantly changes.
*/
public RANSACRadialDistortionRobustEstimator(final RadialDistortionRobustEstimatorListener listener) {
super(listener);
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor.
*
* @param distortedPoints list of distorted points. Distorted points are
* obtained after radial distortion is applied to an undistorted point.
* @param undistortedPoints list of undistorted points.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
*/
public RANSACRadialDistortionRobustEstimator(
final List<Point2D> distortedPoints, final List<Point2D> undistortedPoints) {
super(distortedPoints, undistortedPoints);
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor.
*
* @param distortedPoints list of distorted points. Distorted points are
* obtained after radial distortion is applied to an undistorted point.
* @param undistortedPoints list of undistorted points.
* @param listener listener to be notified of events such as when
* estimation starts, ends or its progress significantly changes.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
*/
public RANSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
final List<Point2D> undistortedPoints,
final RadialDistortionRobustEstimatorListener listener) {
super(distortedPoints, undistortedPoints, listener);
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor.
*
* @param distortedPoints list of distorted points. Distorted points are
* obtained after radial distortion is applied to an undistorted point.
* @param undistortedPoints list of undistorted points.
* @param distortionCenter radial distortion center. If null it is assumed
* to be the origin of coordinates, otherwise this is typically equal to
* the camera principal point.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
*/
public RANSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
final List<Point2D> undistortedPoints,
final Point2D distortionCenter) {
super(distortedPoints, undistortedPoints, distortionCenter);
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor.
*
* @param distortedPoints list of distorted points. Distorted points are
* obtained after radial distortion is applied to an undistorted point.
* @param undistortedPoints list of undistorted points.
* @param distortionCenter radial distortion center. If null it is assumed
* to be the origin of coordinates, otherwise this is typically equal to
* the camera principal point.
* @param listener listener to be notified of events such as when
* estimation starts, ends or its progress significantly changes.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
*/
public RANSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
final List<Point2D> undistortedPoints,
final Point2D distortionCenter,
final RadialDistortionRobustEstimatorListener listener) {
super(distortedPoints, undistortedPoints, distortionCenter, listener);
threshold = DEFAULT_THRESHOLD;
}
/**
* Returns threshold to determine whether points are inliers or not when
* testing possible estimation solutions.
* The threshold refers to the amount of error (i.e. Euclidean distance) a
* possible solution has on projected 2D points.
*
* @return threshold to determine whether points are inliers or not when
* testing possible estimation solutions.
*/
public double getThreshold() {
return threshold;
}
/**
* Sets threshold to determine whether points are inliers or not when
* testing possible estimation solutions.
* The threshold refers to the amount of error (i.e. Euclidean distance) a
* possible solution has on projected 2D points.
*
* @param threshold threshold to be set.
* @throws IllegalArgumentException if provided value is equal or less than
* zero.
* @throws LockedException if robust estimator is locked because an
* estimation is already in progress.
*/
public void setThreshold(final double threshold) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
if (threshold <= MIN_THRESHOLD) {
throw new IllegalArgumentException();
}
this.threshold = threshold;
}
/**
* Estimates a radial distortion using a robust estimator and
* the best set of matched 2D points found using the robust estimator.
*
* @return a radial distortion.
* @throws LockedException if robust estimator is locked because an
* estimation is already in progress.
* @throws NotReadyException if provided input data is not enough to start
* the estimation.
* @throws RobustEstimatorException if estimation fails for any reason
* (i.e. numerical instability, no solution available, etc).
*/
@SuppressWarnings("DuplicatedCode")
@Override
public RadialDistortion estimate() throws LockedException, NotReadyException, RobustEstimatorException {
if (isLocked()) {
throw new LockedException();
}
if (!isReady()) {
throw new NotReadyException();
}
final var innerEstimator = new RANSACRobustEstimator<RadialDistortion>(new RANSACRobustEstimatorListener<>() {
// point to be reused when computing residuals
private final Point2D testPoint = Point2D.create(CoordinatesType.INHOMOGENEOUS_COORDINATES);
// non-robust radial distortion estimator
private final LMSERadialDistortionEstimator radialDistortionEstimator = new LMSERadialDistortionEstimator();
// subset of distorted (i.e. measured) points
private final List<Point2D> subsetDistorted = new ArrayList<>();
// subset of undistorted (i.e. ideal) points
private final List<Point2D> subsetUndistorted = new ArrayList<>();
@Override
public double getThreshold() {
return threshold;
}
@Override
public int getTotalSamples() {
return distortedPoints.size();
}
@Override
public int getSubsetSize() {
return MIN_NUMBER_OF_POINTS;
}
@Override
public void estimatePreliminarSolutions(
final int[] samplesIndices, final List<RadialDistortion> solutions) {
subsetDistorted.clear();
subsetDistorted.add(distortedPoints.get(samplesIndices[0]));
subsetDistorted.add(distortedPoints.get(samplesIndices[1]));
subsetUndistorted.clear();
subsetUndistorted.add(undistortedPoints.get(samplesIndices[0]));
subsetUndistorted.add(undistortedPoints.get(samplesIndices[1]));
try {
radialDistortionEstimator.setPoints(distortedPoints, undistortedPoints);
radialDistortionEstimator.setPoints(subsetDistorted, subsetUndistorted);
final var distortion = radialDistortionEstimator.estimate();
solutions.add(distortion);
} catch (final Exception e) {
// if anything fails, no solution is added
}
}
@Override
public double computeResidual(final RadialDistortion currentEstimation, final int i) {
final var distortedPoint = distortedPoints.get(i);
final var undistortedPoint = undistortedPoints.get(i);
currentEstimation.distort(undistortedPoint, testPoint);
return testPoint.distanceTo(distortedPoint);
}
@Override
public boolean isReady() {
return RANSACRadialDistortionRobustEstimator.this.isReady();
}
@Override
public void onEstimateStart(final RobustEstimator<RadialDistortion> estimator) {
try {
radialDistortionEstimator.setLMSESolutionAllowed(false);
radialDistortionEstimator.setIntrinsic(getIntrinsic());
} catch (final Exception e) {
Logger.getLogger(RANSACRadialDistortionRobustEstimator.class.getName()).log(Level.WARNING,
"Could not set intrinsic parameters on radial distortion estimator", e);
}
if (listener != null) {
listener.onEstimateStart(RANSACRadialDistortionRobustEstimator.this);
}
}
@Override
public void onEstimateEnd(final RobustEstimator<RadialDistortion> estimator) {
if (listener != null) {
listener.onEstimateEnd(RANSACRadialDistortionRobustEstimator.this);
}
}
@Override
public void onEstimateNextIteration(
final RobustEstimator<RadialDistortion> estimator, final int iteration) {
if (listener != null) {
listener.onEstimateNextIteration(RANSACRadialDistortionRobustEstimator.this, iteration);
}
}
@Override
public void onEstimateProgressChange(
final RobustEstimator<RadialDistortion> estimator, final float progress) {
if (listener != null) {
listener.onEstimateProgressChange(RANSACRadialDistortionRobustEstimator.this, progress);
}
}
});
try {
locked = true;
innerEstimator.setConfidence(confidence);
innerEstimator.setMaxIterations(maxIterations);
innerEstimator.setProgressDelta(progressDelta);
return innerEstimator.estimate();
} catch (final com.irurueta.numerical.LockedException e) {
throw new LockedException(e);
} catch (final com.irurueta.numerical.NotReadyException e) {
throw new NotReadyException(e);
} finally {
locked = false;
}
}
/**
* Returns method being used for robust estimation
*
* @return method being used for robust estimation
*/
@Override
public RobustEstimatorMethod getMethod() {
return RobustEstimatorMethod.RANSAC;
}
}