MSACUPnPPointCorrespondencePinholeCameraRobustEstimator.java
/*
* Copyright (C) 2017 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.CoordinatesType;
import com.irurueta.geometry.PinholeCamera;
import com.irurueta.geometry.Point2D;
import com.irurueta.geometry.Point3D;
import com.irurueta.numerical.robust.MSACRobustEstimator;
import com.irurueta.numerical.robust.MSACRobustEstimatorListener;
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;
/**
* Finds the best pinhole camera for provided collections of matched 2D/3D
* points using MSAC + UPnP algorithms.
*/
@SuppressWarnings("DuplicatedCode")
public class MSACUPnPPointCorrespondencePinholeCameraRobustEstimator extends
UPnPPointCorrespondencePinholeCameraRobustEstimator {
/**
* 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 MSACUPnPPointCorrespondencePinholeCameraRobustEstimator() {
super();
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor with listener.
*
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
*/
public MSACUPnPPointCorrespondencePinholeCameraRobustEstimator(
final PinholeCameraRobustEstimatorListener listener) {
super(listener);
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor with lists of points to be used to estimate a pinhole camera.
* Points in the lists 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 MIN_NUMBER_OF_POINT_CORRESPONDENCES (6 points).
*
* @param points3D list of 3D points used to estimate a pinhole camera.
* @param points2D list of corresponding projected 2D points used to
* estimate a pinhole camera.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than required minimum size (6
* correspondences).
*/
public MSACUPnPPointCorrespondencePinholeCameraRobustEstimator(
final List<Point3D> points3D, final List<Point2D> points2D) {
super(points3D, points2D);
threshold = DEFAULT_THRESHOLD;
}
/**
* Constructor with listener and lists of points to be used to estimate a
* pinhole camera.
* Points in the lists 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 MIN_NUMBER_OF_POINT_CORRESPONDENCES (6 points).
*
* @param listener listener to be notified of events such as when estimation
* starts, ends or its progress significantly changes.
* @param points3D list of 3D points used to estimate a pinhole camera.
* @param points2D list of corresponding projected 2D points used to
* estimate a pinhole camera.
* @throws IllegalArgumentException if provided lists of points don't have
* the same size or their size is smaller than required minimum size (6
* correspondences).
*/
public MSACUPnPPointCorrespondencePinholeCameraRobustEstimator(
final PinholeCameraRobustEstimatorListener listener,
final List<Point3D> points3D, final List<Point2D> points2D) {
super(listener, points3D, points2D);
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 pinhole camera using a robust estimator and
* the best set of matched 2D/3D point correspondences or 2D line/3D plane
* correspondences found using the robust estimator.
*
* @return a pinhole camera.
* @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 PinholeCamera estimate() throws LockedException, NotReadyException, RobustEstimatorException {
if (isLocked()) {
throw new LockedException();
}
if (!isReady()) {
throw new NotReadyException();
}
// pinhole camera estimator using UPnP (Uncalibrated Perspective-n-Point) algorithm
final var nonRobustEstimator = new UPnPPointCorrespondencePinholeCameraEstimator();
nonRobustEstimator.setPlanarConfigurationAllowed(planarConfigurationAllowed);
nonRobustEstimator.setNullspaceDimension2Allowed(nullspaceDimension2Allowed);
nonRobustEstimator.setPlanarThreshold(planarThreshold);
nonRobustEstimator.setSkewness(skewness);
nonRobustEstimator.setHorizontalPrincipalPoint(horizontalPrincipalPoint);
nonRobustEstimator.setVerticalPrincipalPoint(verticalPrincipalPoint);
// suggestions
nonRobustEstimator.setSuggestSkewnessValueEnabled(isSuggestSkewnessValueEnabled());
nonRobustEstimator.setSuggestedSkewnessValue(getSuggestedSkewnessValue());
nonRobustEstimator.setSuggestHorizontalFocalLengthEnabled(isSuggestHorizontalFocalLengthEnabled());
nonRobustEstimator.setSuggestedHorizontalFocalLengthValue(getSuggestedHorizontalFocalLengthValue());
nonRobustEstimator.setSuggestVerticalFocalLengthEnabled(isSuggestVerticalFocalLengthEnabled());
nonRobustEstimator.setSuggestedVerticalFocalLengthValue(getSuggestedVerticalFocalLengthValue());
nonRobustEstimator.setSuggestAspectRatioEnabled(isSuggestAspectRatioEnabled());
nonRobustEstimator.setSuggestedAspectRatioValue(getSuggestedAspectRatioValue());
nonRobustEstimator.setSuggestPrincipalPointEnabled(isSuggestPrincipalPointEnabled());
nonRobustEstimator.setSuggestedPrincipalPointValue(getSuggestedPrincipalPointValue());
nonRobustEstimator.setSuggestRotationEnabled(isSuggestRotationEnabled());
nonRobustEstimator.setSuggestedRotationValue(getSuggestedRotationValue());
nonRobustEstimator.setSuggestCenterEnabled(isSuggestCenterEnabled());
nonRobustEstimator.setSuggestedCenterValue(getSuggestedCenterValue());
final var innerEstimator = new MSACRobustEstimator<>(new MSACRobustEstimatorListener<PinholeCamera>() {
// point to be reused when computing residuals
private final Point2D testPoint = Point2D.create(CoordinatesType.HOMOGENEOUS_COORDINATES);
// 3D points for a subset of samples
private final List<Point3D> subset3D = new ArrayList<>();
// 2D points for a subset of samples
private final List<Point2D> subset2D = new ArrayList<>();
@Override
public double getThreshold() {
return threshold;
}
@Override
public int getTotalSamples() {
return points3D.size();
}
@Override
public int getSubsetSize() {
return PointCorrespondencePinholeCameraEstimator.MIN_NUMBER_OF_POINT_CORRESPONDENCES;
}
@Override
public void estimatePreliminarSolutions(final int[] samplesIndices, final List<PinholeCamera> solutions) {
subset3D.clear();
subset3D.add(points3D.get(samplesIndices[0]));
subset3D.add(points3D.get(samplesIndices[1]));
subset3D.add(points3D.get(samplesIndices[2]));
subset3D.add(points3D.get(samplesIndices[3]));
subset3D.add(points3D.get(samplesIndices[4]));
subset3D.add(points3D.get(samplesIndices[5]));
subset2D.clear();
subset2D.add(points2D.get(samplesIndices[0]));
subset2D.add(points2D.get(samplesIndices[1]));
subset2D.add(points2D.get(samplesIndices[2]));
subset2D.add(points2D.get(samplesIndices[3]));
subset2D.add(points2D.get(samplesIndices[4]));
subset2D.add(points2D.get(samplesIndices[5]));
try {
nonRobustEstimator.setLists(subset3D, subset2D);
final var cam = nonRobustEstimator.estimate();
solutions.add(cam);
} catch (final Exception e) {
// if points configuration is degenerate, no solution is
// added
}
}
@Override
public double computeResidual(final PinholeCamera currentEstimation, final int i) {
// pick i-th points
final var point3D = points3D.get(i);
final var point2D = points2D.get(i);
// project point3D into test point
currentEstimation.project(point3D, testPoint);
// compare test point and 2D point
return testPoint.distanceTo(point2D);
}
@Override
public boolean isReady() {
return MSACUPnPPointCorrespondencePinholeCameraRobustEstimator.this.isReady();
}
@Override
public void onEstimateStart(final RobustEstimator<PinholeCamera> estimator) {
if (listener != null) {
listener.onEstimateStart(MSACUPnPPointCorrespondencePinholeCameraRobustEstimator.this);
}
}
@Override
public void onEstimateEnd(final RobustEstimator<PinholeCamera> estimator) {
if (listener != null) {
listener.onEstimateEnd(MSACUPnPPointCorrespondencePinholeCameraRobustEstimator.this);
}
}
@Override
public void onEstimateNextIteration(final RobustEstimator<PinholeCamera> estimator, int iteration) {
if (listener != null) {
listener.onEstimateNextIteration(
MSACUPnPPointCorrespondencePinholeCameraRobustEstimator.this, iteration);
}
}
@Override
public void onEstimateProgressChange(final RobustEstimator<PinholeCamera> estimator, float progress) {
if (listener != null) {
listener.onEstimateProgressChange(
MSACUPnPPointCorrespondencePinholeCameraRobustEstimator.this, progress);
}
}
});
try {
locked = true;
inliersData = null;
innerEstimator.setConfidence(confidence);
innerEstimator.setMaxIterations(maxIterations);
innerEstimator.setProgressDelta(progressDelta);
final var result = innerEstimator.estimate();
inliersData = innerEstimator.getInliersData();
return attemptRefine(result, nonRobustEstimator.getMaxSuggestionWeight());
} 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.MSAC;
}
/**
* 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;
}
}