PROSACPointCorrespondenceAffineTransformation2DRobustEstimator.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.geometry.estimators;
import com.irurueta.geometry.AffineTransformation2D;
import com.irurueta.geometry.CoincidentPointsException;
import com.irurueta.geometry.CoordinatesType;
import com.irurueta.geometry.Point2D;
import com.irurueta.numerical.robust.PROSACRobustEstimator;
import com.irurueta.numerical.robust.PROSACRobustEstimatorListener;
import com.irurueta.numerical.robust.RobustEstimator;
import com.irurueta.numerical.robust.RobustEstimatorException;
import com.irurueta.numerical.robust.RobustEstimatorMethod;
import java.util.List;
/**
* Finds the best affine 2D transformation for provided collections of matched
* 2D points using PROSAC algorithm.
*/
@SuppressWarnings("DuplicatedCode")
public class PROSACPointCorrespondenceAffineTransformation2DRobustEstimator
extends PointCorrespondenceAffineTransformation2DRobustEstimator {
/**
* 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;
/**
* Indicates that by default inliers will only be computed but not kept.
*/
public static final boolean DEFAULT_COMPUTE_AND_KEEP_INLIERS = false;
/**
* Indicates that by default residuals will only be computed but not kept.
*/
public static final boolean DEFAULT_COMPUTE_AND_KEEP_RESIDUALS = false;
/**
* 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;
/**
* Quality scores corresponding to each pair of matched points.
* The larger the score value the better the quality of the matching.
*/
private double[] qualityScores;
/**
* Indicates whether inliers must be computed and kept.
*/
private boolean computeAndKeepInliers;
/**
* Indicates whether residuals must be computed and kept.
*/
private boolean computeAndKeepResiduals;
/**
* Constructor.
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator() {
super();
threshold = DEFAULT_THRESHOLD;
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* Constructor with lists of points to be used to estimate an affine 2D
* transformation.
* Points in the list located at the same position are considered to be
* matched. Hence, both lists must have the same size, and their size must
* be greater or equal than MINIMUM_SIZE.
*
* @param inputPoints list of input points to be used to estimate an
* affine 2D transformation.
* @param outputPoints list of output points to be used to estimate an
* affine 2D transformation.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than MINIMUM_SIZE.
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator(
final List<Point2D> inputPoints, final List<Point2D> outputPoints) {
super(inputPoints, outputPoints);
threshold = DEFAULT_THRESHOLD;
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* Constructor.
*
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator(
final AffineTransformation2DRobustEstimatorListener listener) {
super(listener);
threshold = DEFAULT_THRESHOLD;
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* Constructor with listener and lists of points to be used to estimate an
* affine 2D transformation.
* Points in the list located at the same position are considered to be
* matched. Hence, both lists must have the same size, and their size must
* be greater or equal than MINIMUM_SIZE.
*
* @param listener listener to be notified of events such as when estimation
* stars, ends or its progress significantly changes.
* @param inputPoints list of input points to be used to estimate an
* affine 2D transformation.
* @param outputPoints list of output points to be used to estimate an
* affine 2D transformation.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than MINIMUM_SIZE.
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator(
final AffineTransformation2DRobustEstimatorListener listener,
final List<Point2D> inputPoints, final List<Point2D> outputPoints) {
super(listener, inputPoints, outputPoints);
threshold = DEFAULT_THRESHOLD;
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* Constructor.
*
* @param qualityScores quality scores corresponding to each pair of matched
* points.
* @throws IllegalArgumentException if provided quality scores length is
* smaller than MINIMUM_SIZE (i.e. 3 samples).
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator(final double[] qualityScores) {
super();
threshold = DEFAULT_THRESHOLD;
internalSetQualityScores(qualityScores);
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* Constructor with lists of points to be used to estimate an affine 2D
* transformation.
* Points in the list located at the same position are considered to be
* matched. Hence, both lists must have the same size, and their size must
* be greater or equal than MINIMUM_SIZE.
*
* @param inputPoints list of input points to be used to estimate an
* affine 2D transformation.
* @param outputPoints list of output points to be used to estimate an
* affine 2D transformation.
* @param qualityScores quality scores corresponding to each pair of matched
* points.
* @throws IllegalArgumentException if provided lists of points and array
* of quality scores don't have the same size or their size is smaller than
* MINIMUM_SIZE.
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator(
final List<Point2D> inputPoints, final List<Point2D> outputPoints, final double[] qualityScores) {
super(inputPoints, outputPoints);
if (qualityScores.length != inputPoints.size()) {
throw new IllegalArgumentException();
}
threshold = DEFAULT_THRESHOLD;
internalSetQualityScores(qualityScores);
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* Constructor.
*
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @param qualityScores quality scores corresponding to each pair of matched
* points.
* @throws IllegalArgumentException if provided quality scores length is
* smaller than MINIMUM_SIZE (i.e. 3 samples).
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator(
final AffineTransformation2DRobustEstimatorListener listener, final double[] qualityScores) {
super(listener);
threshold = DEFAULT_THRESHOLD;
internalSetQualityScores(qualityScores);
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* Constructor with listener and lists of points to be used to estimate an
* affine 2D transformation.
* Points in the list located at the same position are considered to be
* matched. Hence, both lists must have the same size, and their size must
* be greater or equal than MINIMUM_SIZE.
*
* @param listener listener to be notified of events such as when estimation
* stars, ends or its progress significantly changes.
* @param inputPoints list of input points to be used to estimate an
* affine 2D transformation.
* @param outputPoints list of output points to be used to estimate an
* affine 2D transformation.
* @param qualityScores quality scores corresponding to each pair of matched
* points.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than MINIMUM_SIZE.
*/
public PROSACPointCorrespondenceAffineTransformation2DRobustEstimator(
final AffineTransformation2DRobustEstimatorListener listener,
final List<Point2D> inputPoints, final List<Point2D> outputPoints, final double[] qualityScores) {
super(listener, inputPoints, outputPoints);
if (qualityScores.length != inputPoints.size()) {
throw new IllegalArgumentException();
}
threshold = DEFAULT_THRESHOLD;
internalSetQualityScores(qualityScores);
computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
}
/**
* 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 a matched pair of 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 a matched pair of points.
*
* @param threshold threshold to determine whether points are inliers or not
* when testing possible estimation solutions.
* @throws IllegalArgumentException if provided values 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;
}
/**
* Returns quality scores corresponding to each pair of matched points.
* The larger the score value the better the quality of the matching.
*
* @return quality scores corresponding to each pair of matched points.
*/
@Override
public double[] getQualityScores() {
return qualityScores;
}
/**
* Sets quality scores corresponding to each pair of matched points.
* The larger the score value the better the quality of the matching.
*
* @param qualityScores quality scores corresponding to each pair of matched
* points.
* @throws LockedException if robust estimator is locked because an
* estimation is already in progress.
* @throws IllegalArgumentException if provided quality scores length is
* smaller than MINIMUM_SIZE (i.e. 3 samples).
*/
@Override
public void setQualityScores(final double[] qualityScores) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
internalSetQualityScores(qualityScores);
}
/**
* Indicates if estimator is ready to start the affine 2D transformation
* estimation.
* This is true when input data (i.e. lists of matched points and quality
* scores) are provided and a minimum of MINIMUM_SIZE points are available.
*
* @return true if estimator is ready, false otherwise.
*/
@Override
public boolean isReady() {
return super.isReady() && qualityScores != null && qualityScores.length == inputPoints.size();
}
/**
* Indicates whether inliers must be computed and kept.
*
* @return true if inliers must be computed and kept, false if inliers
* only need to be computed but not kept.
*/
public boolean isComputeAndKeepInliersEnabled() {
return computeAndKeepInliers;
}
/**
* Specifies whether inliers must be computed and kept.
*
* @param computeAndKeepInliers true if inliers must be computed and kept,
* false if inliers only need to be computed but not kept.
* @throws LockedException if estimator is locked.
*/
public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
this.computeAndKeepInliers = computeAndKeepInliers;
}
/**
* Indicates whether residuals must be computed and kept.
*
* @return true if residuals must be computed and kept, false if residuals
* only need to be computed but not kept.
*/
public boolean isComputeAndKeepResidualsEnabled() {
return computeAndKeepResiduals;
}
/**
* Specifies whether residuals must be computed and kept.
*
* @param computeAndKeepResiduals true if residuals must be computed and
* kept, false if residuals only need to be computed but not kept.
* @throws LockedException if estimator is locked.
*/
public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
if (isLocked()) {
throw new LockedException();
}
this.computeAndKeepResiduals = computeAndKeepResiduals;
}
/**
* Estimates an affine 2D transformation using a robust estimator and
* the best set of matched 2D point correspondences found using the robust
* estimator.
*
* @return an affine 2D transformation.
* @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).
*/
@Override
public AffineTransformation2D estimate() throws LockedException, NotReadyException, RobustEstimatorException {
if (isLocked()) {
throw new LockedException();
}
if (!isReady()) {
throw new NotReadyException();
}
final var innerEstimator = new PROSACRobustEstimator<>(
new PROSACRobustEstimatorListener<AffineTransformation2D>() {
// point to be reused when computing residuals
private final Point2D testPoint = Point2D.create(CoordinatesType.HOMOGENEOUS_COORDINATES);
@Override
public double getThreshold() {
return threshold;
}
@Override
public int getTotalSamples() {
return inputPoints.size();
}
@Override
public int getSubsetSize() {
return AffineTransformation2DRobustEstimator.MINIMUM_SIZE;
}
@Override
public void estimatePreliminarSolutions(
final int[] samplesIndices, final List<AffineTransformation2D> solutions) {
final var inputPoint1 = inputPoints.get(samplesIndices[0]);
final var inputPoint2 = inputPoints.get(samplesIndices[1]);
final var inputPoint3 = inputPoints.get(samplesIndices[2]);
final var outputPoint1 = outputPoints.get(samplesIndices[0]);
final var outputPoint2 = outputPoints.get(samplesIndices[1]);
final var outputPoint3 = outputPoints.get(samplesIndices[2]);
try {
final var transformation = new AffineTransformation2D(inputPoint1, inputPoint2, inputPoint3,
outputPoint1, outputPoint2, outputPoint3);
solutions.add(transformation);
} catch (final CoincidentPointsException e) {
// if points are coincident, no solution is added
}
}
@Override
public double computeResidual(final AffineTransformation2D currentEstimation, final int i) {
final var inputPoint = inputPoints.get(i);
final var outputPoint = outputPoints.get(i);
// transform input point and store result in mTestPoint
currentEstimation.transform(inputPoint, testPoint);
return outputPoint.distanceTo(testPoint);
}
@Override
public boolean isReady() {
return PROSACPointCorrespondenceAffineTransformation2DRobustEstimator.this.isReady();
}
@Override
public void onEstimateStart(final RobustEstimator<AffineTransformation2D> estimator) {
if (mListener != null) {
mListener.onEstimateStart(
PROSACPointCorrespondenceAffineTransformation2DRobustEstimator.this);
}
}
@Override
public void onEstimateEnd(final RobustEstimator<AffineTransformation2D> estimator) {
if (mListener != null) {
mListener.onEstimateEnd(
PROSACPointCorrespondenceAffineTransformation2DRobustEstimator.this);
}
}
@Override
public void onEstimateNextIteration(
final RobustEstimator<AffineTransformation2D> estimator, final int iteration) {
if (mListener != null) {
mListener.onEstimateNextIteration(
PROSACPointCorrespondenceAffineTransformation2DRobustEstimator.this,
iteration);
}
}
@Override
public void onEstimateProgressChange(
final RobustEstimator<AffineTransformation2D> estimator, final float progress) {
if (mListener != null) {
mListener.onEstimateProgressChange(
PROSACPointCorrespondenceAffineTransformation2DRobustEstimator.this,
progress);
}
}
@Override
public double[] getQualityScores() {
return qualityScores;
}
});
try {
locked = true;
inliersData = null;
innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
innerEstimator.setConfidence(confidence);
innerEstimator.setMaxIterations(maxIterations);
innerEstimator.setProgressDelta(progressDelta);
final var transformation = innerEstimator.estimate();
inliersData = innerEstimator.getInliersData();
return attemptRefine(transformation);
} 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.PROSAC;
}
/**
* Gets standard deviation used for Levenberg-Marquardt fitting during
* refinement.
* Returned value gives an indication of how much variance each residual
* has.
* Typically, this value is related to the threshold used on each robust
* estimation, since residuals of found inliers are within the range of
* such threshold.
*
* @return standard deviation used for refinement.
*/
@Override
protected double getRefinementStandardDeviation() {
return threshold;
}
/**
* Sets quality scores corresponding to each pair of matched points.
* This method is used internally and does not check whether instance is
* locked or not.
*
* @param qualityScores quality scores to be set.
* @throws IllegalArgumentException if provided quality scores length is
* smaller than MINIMUM_SIZE.
*/
private void internalSetQualityScores(final double[] qualityScores) {
if (qualityScores.length < MINIMUM_SIZE) {
throw new IllegalArgumentException();
}
this.qualityScores = qualityScores;
}
}