PROSACDLTPointCorrespondencePinholeCameraRobustEstimator.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.CoordinatesType;
import com.irurueta.geometry.PinholeCamera;
import com.irurueta.geometry.Point2D;
import com.irurueta.geometry.Point3D;
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.ArrayList;
import java.util.List;

/**
 * Finds the best pinhole camera for provided collections of matched 2D/3D
 * points using PROSAC algorithm.
 */
@SuppressWarnings("DuplicatedCode")
public class PROSACDLTPointCorrespondencePinholeCameraRobustEstimator extends
        DLTPointCorrespondencePinholeCameraRobustEstimator {

    /**
     * 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 PROSACDLTPointCorrespondencePinholeCameraRobustEstimator() {
        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 a pinhole camera.
     * 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 MIN_NUMBER_OF_POINT_CORRESPONDENCES.
     *
     * @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 PROSACDLTPointCorrespondencePinholeCameraRobustEstimator(
            final List<Point3D> points3D, final List<Point2D> points2D) {
        super(points3D, points2D);
        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 PROSACDLTPointCorrespondencePinholeCameraRobustEstimator(
            final PinholeCameraRobustEstimatorListener 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 ot estimate a
     * pinhole camera.
     * 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 MIN_NUMBER_OF_POINT_CORRESPONDENCES.
     *
     * @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 PROSACDLTPointCorrespondencePinholeCameraRobustEstimator(
            final PinholeCameraRobustEstimatorListener listener,
            final List<Point3D> points3D, final List<Point2D> points2D) {
        super(listener, points3D, points2D);
        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 PROSACDLTPointCorrespondencePinholeCameraRobustEstimator(final double[] qualityScores) {
        super();
        threshold = DEFAULT_THRESHOLD;
        computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
        computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
        internalSetQualityScores(qualityScores);
    }

    /**
     * Constructor with lists of points to be used to estimate a pinhole camera.
     * 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 MIN_NUMBER_OF_POINT_CORRESPONDENCES.
     *
     * @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.
     * @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
     *                                  6 correspondences.
     */
    public PROSACDLTPointCorrespondencePinholeCameraRobustEstimator(
            final List<Point3D> points3D, final List<Point2D> points2D, final double[] qualityScores) {
        super(points3D, points2D);

        if (qualityScores.length != points3D.size()) {
            throw new IllegalArgumentException();
        }

        threshold = DEFAULT_THRESHOLD;
        computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
        computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
        internalSetQualityScores(qualityScores);
    }

    /**
     * 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 PROSACDLTPointCorrespondencePinholeCameraRobustEstimator(
            final PinholeCameraRobustEstimatorListener listener, final double[] qualityScores) {
        super(listener);
        threshold = DEFAULT_THRESHOLD;
        computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
        computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
        internalSetQualityScores(qualityScores);
    }

    /**
     * Constructor with listener and lists of points to be used ot estimate a
     * pinhole camera.
     * 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 MIN_NUMBER_OF_POINT_CORRESPONDENCES.
     *
     * @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.
     * @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
     *                                  MIN_NUMBER_OF_POINT_CORRESPONDENCES.
     */
    public PROSACDLTPointCorrespondencePinholeCameraRobustEstimator(
            final PinholeCameraRobustEstimatorListener listener, final List<Point3D> points3D,
            final List<Point2D> points2D, final double[] qualityScores) {
        super(listener, points3D, points2D);

        if (qualityScores.length != points3D.size()) {
            throw new IllegalArgumentException();
        }

        threshold = DEFAULT_THRESHOLD;
        computeAndKeepInliers = DEFAULT_COMPUTE_AND_KEEP_INLIERS;
        computeAndKeepResiduals = DEFAULT_COMPUTE_AND_KEEP_RESIDUALS;
        internalSetQualityScores(qualityScores);
    }

    /**
     * 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.
     * @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 == points3D.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 PinholeCamera estimate() throws LockedException, NotReadyException, RobustEstimatorException {
        if (isLocked()) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        // pinhole camera estimator using DLT (Direct Linear Transform) algorithm
        final var nonRobustEstimator = new DLTPointCorrespondencePinholeCameraEstimator();

        nonRobustEstimator.setLMSESolutionAllowed(false);
        nonRobustEstimator.setPointCorrespondencesNormalized(normalizeSubsetPointCorrespondences);

        // 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 PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<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 PointCorrespondencePinholeCameraRobustEstimator.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 PROSACDLTPointCorrespondencePinholeCameraRobustEstimator.this.isReady();
            }

            @Override
            public void onEstimateStart(final RobustEstimator<PinholeCamera> estimator) {
                if (listener != null) {
                    listener.onEstimateStart(PROSACDLTPointCorrespondencePinholeCameraRobustEstimator.this);
                }
            }

            @Override
            public void onEstimateEnd(final RobustEstimator<PinholeCamera> estimator) {
                if (listener != null) {
                    listener.onEstimateEnd(PROSACDLTPointCorrespondencePinholeCameraRobustEstimator.this);
                }
            }

            @Override
            public void onEstimateNextIteration(final RobustEstimator<PinholeCamera> estimator, final int iteration) {
                if (listener != null) {
                    listener.onEstimateNextIteration(
                            PROSACDLTPointCorrespondencePinholeCameraRobustEstimator.this, iteration);
                }
            }

            @Override
            public void onEstimateProgressChange(final RobustEstimator<PinholeCamera> estimator, final float progress) {
                if (listener != null) {
                    listener.onEstimateProgressChange(
                            PROSACDLTPointCorrespondencePinholeCameraRobustEstimator.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 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.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 < MIN_NUMBER_OF_POINT_CORRESPONDENCES) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}