/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2001-2012, Open Source Geospatial Foundation (OSGeo)
* (C) 2009-2012, Geomatys
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotoolkit.coverage.grid;
import java.awt.Rectangle;
import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.util.List;
import javax.media.jai.Interpolation;
import javax.media.jai.InterpolationNearest;
import org.geotoolkit.image.iterator.PixelIterator;
import org.geotoolkit.image.iterator.PixelIteratorFactory;
import org.opengis.coverage.CannotEvaluateException;
import org.opengis.coverage.PointOutsideCoverageException;
import org.opengis.referencing.operation.MathTransform2D;
import org.opengis.referencing.operation.NoninvertibleTransformException;
import org.opengis.referencing.operation.TransformException;
/**
* A grid coverage using an {@linkplain Interpolation interpolation} for evaluating points. This
* interpolator is not used for {@linkplain InterpolationNearest nearest-neighbor interpolation}
* (use the plain {@link GridCoverage2D} class for that). It should work for other kinds of
* interpolation however.
*
* @author Martin Desruisseaux (IRD)
* @version 3.00
*
* @since 1.2
* @module
*/
public final class Interpolator2D extends Calculator2D {
/**
* For cross-version compatibility.
*/
private static final long serialVersionUID = 9028980295030908004L;
/**
* The greatest value smaller than 1 representable as a {@code float} number.
* This value can be obtained with {@code -Math.nextUp(-1f)}.
*/
private static final float ONE_EPSILON = 0.99999994f;
/**
* Default interpolations, in preference order. Will be constructed only when first needed.
*/
private static Interpolation[] DEFAULTS;
/**
* Transform from "real world" coordinates to grid coordinates.
* This transform maps coordinates to pixel <em>centers</em>.
*/
private final MathTransform2D toGrid;
/**
* The interpolation method.
*/
private final Interpolation interpolation;
/**
* Second interpolation method to use if this one failed. May be {@code null} if there
* is no fallback. By convention, {@code this} means that interpolation should fallback
* on {@code super.evaluate(...)} (i.e. nearest neighbor).
*/
private final Interpolator2D fallback;
/**
* Image bounds. Bounds have been reduced by {@link Interpolation}'s padding.
*/
private final int xmin, ymin, xmax, ymax;
/**
* Interpolation padding.
*/
private final int top, left;
/**
* The interpolation bounds. Interpolation will use pixel inside this rectangle.
* This rectangle is passed as an argument to {@link RectIterFactory}.
*/
private final Rectangle bounds;
/**
* Arrays to use for passing arguments to interpolation.
* This array will be constructed only when first needed.
*/
private transient double[][] doubles;
/**
* Arrays to use for passing arguments to interpolation.
* This array will be constructed only when first needed.
*/
private transient float[][] floats;
/**
* Arrays to use for passing arguments to interpolation.
* This array will be constructed only when first needed.
*/
private transient int[][] ints;
/**
* Image iterator, initialized at first interpolation.
*/
private transient PixelIterator iterator;
/**
* Constructs a new interpolator using default interpolations.
*
* @param coverage The coverage to interpolate.
* @return A grid coverage using the default interpolations.
*/
public static GridCoverage2D create(final GridCoverage2D coverage) {
// No need to synchronize: not a big deal if two arrays are created.
if (DEFAULTS == null) {
DEFAULTS = new Interpolation[] {
Interpolation.getInstance(Interpolation.INTERP_BICUBIC),
Interpolation.getInstance(Interpolation.INTERP_BILINEAR),
Interpolation.getInstance(Interpolation.INTERP_NEAREST)
};
}
return create(coverage, DEFAULTS);
}
/**
* Constructs a new interpolator for an interpolation and its fallbacks. This method is
* typically invoked with only one interpolation method. If more than one interpolation
* is given, then the supplemental interpolations are <cite>fallbacks</cite>. The fallbacks
* are used if the primary interpolation failed because of {@linkplain Float#NaN NaN} values
* in the interpolated point neighbor.
*
* @param coverage The coverage to interpolate.
* @param interpolations The interpolation to use and its fallback (if any).
* @return A grid coverage using the given interpolations.
*/
public static GridCoverage2D create(GridCoverage2D coverage, final Interpolation... interpolations) {
while (coverage instanceof Calculator2D) {
coverage = ((Calculator2D) coverage).source;
}
if (interpolations.length == 0 || (interpolations[0] instanceof InterpolationNearest)) {
return coverage;
}
return new Interpolator2D(coverage, interpolations, 0);
}
/**
* Constructs a new interpolator for the specified interpolation.
*
* @param coverage The coverage to interpolate.
* @param interpolations The interpolations to use and its fallback
* (if any). This array must have at least 1 element.
* @param index The index of interpolation to use in the {@code interpolations} array.
*/
private Interpolator2D(final GridCoverage2D coverage,
final Interpolation[] interpolations,
final int index)
{
super(null, coverage);
this.interpolation = interpolations[index];
if (index+1 < interpolations.length) {
if (interpolations[index+1] instanceof InterpolationNearest) {
// By convention, 'fallback==this' is for 'super.evaluate(...)'
// (i.e. "NearestNeighbor").
this.fallback = this;
} else {
this.fallback = new Interpolator2D(coverage, interpolations, index+1);
}
} else {
this.fallback = null;
}
/*
* Computes the affine transform from "real world" coordinates to grid coordinates.
* This transform maps coordinates to pixel <em>centers</em>. If this transform has
* already be created during fallback construction, reuse the fallback's instance
* instead of creating a new identical one.
*/
if (fallback!=null && fallback!=this) {
this.toGrid = fallback.toGrid;
} else try {
final MathTransform2D transform = gridGeometry.getGridToCRS2D();
// Note: If we want nearest-neighbor interpolation, we need to add the
// following line (assuming the transform is an 'AffineTransform'):
//
// transform.translate(-0.5, -0.5);
//
// This is because we need to cancel the last 'translate(0.5, 0.5)' that appears
// in GridGeometry's constructor (we must remember that OpenGIS's transform maps
// pixel CENTER, while JAI transforms maps pixel UPPER LEFT corner). For exemple
// the (12.4, 18.9) coordinates still lies on the [12,9] pixel. Since the JAI's
// nearest-neighbor interpolation use 'Math.floor' operation instead of
// 'Math.round', we must follow this convention.
//
// For other kinds of interpolation, we want to maps pixel values to pixel center.
// For example, coordinate (12.5, 18.5) (in floating-point coordinates) lies at
// the center of pixel [12,18] (in integer coordinates); the evaluated value
// should be the exact pixel's value. On the other hand, coordinate (12.5, 19)
// (in floating-point coordinates) lies exactly at the edge between pixels
// [12,19] and [12,20]; the evaluated value should be a mid-value between those
// two pixels. If we want center of mass located at pixel centers, we must keep
// the (0.5, 0.5) translation provided by 'GridGeometry' for interpolation other
// than nearest-neighbor.
toGrid = transform.inverse();
} catch (NoninvertibleTransformException exception) {
throw new IllegalArgumentException(exception);
}
final int left = interpolation.getLeftPadding();
final int right = interpolation.getRightPadding();
final int top = interpolation.getTopPadding();
final int bottom = interpolation.getBottomPadding();
this.top = top;
this.left = left;
final int x = image.getMinX();
final int y = image.getMinY();
this.xmin = x + left;
this.ymin = y + top;
this.xmax = x + image.getWidth() - right;
this.ymax = y + image.getHeight() - bottom;
bounds = new Rectangle(0, 0, interpolation.getWidth(), interpolation.getHeight());
}
private void initIterator() {
if(iterator==null){
iterator = PixelIteratorFactory.createDefaultIterator(image);
}
}
/**
* Invoked by <code>{@linkplain #view view}(type)</code> when the {@linkplain ViewType#PACKED
* packed}, {@linkplain ViewType#GEOPHYSICS geophysics} or {@linkplain ViewType#PHOTOGRAPHIC
* photographic} view of this grid coverage needs to be created. This method applies to the
* new grid coverage the same {@linkplain #getInterpolations interpolations} than this grid
* coverage.
*
* @param view A view derived from the {@linkplain #source source} coverage.
* @return The grid coverage to be returned by {@link #view view}.
*
* @since 2.5
*/
@Override
protected GridCoverage2D specialize(final GridCoverage2D view) {
return create(view, getInterpolations());
}
/**
* Returns the class of the view returned by {@link #specialize}.
*/
@Override
Class<Interpolator2D> getViewClass() {
return Interpolator2D.class;
}
/**
* Returns the interpolations. The first array's element is the interpolation for
* this grid coverage. Other elements (if any) are fallbacks.
*
* @return The interpolations. The returned array contains at least one element.
*/
public Interpolation[] getInterpolations() {
final List<Interpolation> interp = new ArrayList<>(4);
Interpolator2D scan = this;
do {
interp.add(interpolation);
if (scan.fallback == scan) {
interp.add(Interpolation.getInstance(Interpolation.INTERP_NEAREST));
break;
}
scan = scan.fallback;
}
while (scan != null);
return interp.toArray(new Interpolation[interp.size()]);
}
/**
* Returns the primary interpolation used by this {@code Interpolator2D}.
*/
@Override
public Interpolation getInterpolation() {
return interpolation;
}
/**
* Returns a sequence of integer values for a given two-dimensional point in the coverage.
*
* @param coord The coordinate point where to evaluate.
* @param dest An array in which to store values, or {@code null}.
* @return An array containing values.
* @throws CannotEvaluateException if the values can't be computed at the specified coordinate.
* More specifically, {@link PointOutsideCoverageException} is thrown if the evaluation
* failed because the input point has invalid coordinates.
*/
@Override
public int[] evaluate(final Point2D coord, int[] dest) throws CannotEvaluateException {
if (fallback != null) {
dest = super.evaluate(coord, dest);
}
try {
final Point2D pixel = toGrid.transform(coord, null);
final double x = pixel.getX();
final double y = pixel.getY();
if (!Double.isNaN(x) && !Double.isNaN(y)) {
dest = interpolate(x, y, dest, 0, image.getSampleModel().getNumBands());
if (dest != null) {
return dest;
}
}
} catch (TransformException exception) {
throw new CannotEvaluateException(formatEvaluateError(coord, false), exception);
}
throw new PointOutsideCoverageException(formatEvaluateError(coord, true));
}
/**
* Returns a sequence of float values for a given two-dimensional point in the coverage.
*
* @param coord The coordinate point where to evaluate.
* @param dest An array in which to store values, or {@code null}.
* @return An array containing values.
* @throws CannotEvaluateException if the values can't be computed at the specified coordinate.
* More specifically, {@link PointOutsideCoverageException} is thrown if the evaluation
* failed because the input point has invalid coordinates.
*/
@Override
public float[] evaluate(final Point2D coord, float[] dest) throws CannotEvaluateException {
if (fallback != null) {
dest = super.evaluate(coord, dest);
}
try {
final Point2D pixel = toGrid.transform(coord, null);
final double x = pixel.getX();
final double y = pixel.getY();
if (!Double.isNaN(x) && !Double.isNaN(y)) {
dest = interpolate(x, y, dest, 0, image.getSampleModel().getNumBands());
if (dest != null) {
return dest;
}
}
} catch (TransformException exception) {
throw new CannotEvaluateException(formatEvaluateError(coord, false), exception);
}
throw new PointOutsideCoverageException(formatEvaluateError(coord, true));
}
/**
* Returns a sequence of double values for a given two-dimensional point in the coverage.
*
* @param coord The coordinate point where to evaluate.
* @param dest An array in which to store values, or {@code null}.
* @return An array containing values.
* @throws CannotEvaluateException if the values can't be computed at the specified coordinate.
* More specifically, {@link PointOutsideCoverageException} is thrown if the evaluation
* failed because the input point has invalid coordinates.
*/
@Override
public double[] evaluate(final Point2D coord, double[] dest) throws CannotEvaluateException {
if (fallback != null) {
dest = super.evaluate(coord, dest);
}
try {
final Point2D pixel = toGrid.transform(coord, null);
final double x = pixel.getX();
final double y = pixel.getY();
if (!Double.isNaN(x) && !Double.isNaN(y)) {
dest = interpolate(x, y, dest, 0, image.getSampleModel().getNumBands());
if (dest != null) {
return dest;
}
}
} catch (TransformException exception) {
throw new CannotEvaluateException(formatEvaluateError(coord, false), exception);
}
throw new PointOutsideCoverageException(formatEvaluateError(coord, true));
}
/**
* Interpolates at the specified position. If {@code fallback!=null},
* then {@code dest} <strong>must</strong> have been initialized with
* {@code super.evaluate(...)} prior to invoking this method.
*
* @param x The x position in pixel's coordinates.
* @param y The y position in pixel's coordinates.
* @param dest The destination array, or null.
* @param band The first band's index to interpolate.
* @param bandUp The last band's index+1 to interpolate.
* @return {@code null} if point is outside grid coverage.
*/
private synchronized int[] interpolate(final double x, final double y,
int[] dest, int band, final int bandUp)
{
final double x0 = Math.floor(x);
final double y0 = Math.floor(y);
final int ix = (int)x0;
final int iy = (int)y0;
if (!(ix>=xmin && ix<xmax && iy>=ymin && iy<ymax)) {
if (fallback == null) return null;
if (fallback == this) return dest; // super.evaluate(...) succeed prior to this call.
return fallback.interpolate(x, y, dest, band, bandUp);
}
/*
* Creates buffers, if not already created.
*/
int[][] samples = ints;
if (samples == null) {
final int rowCount = interpolation.getHeight();
final int colCount = interpolation.getWidth();
ints = samples = new int[rowCount][];
for (int i=0; i<rowCount; i++) {
samples[i] = new int[colCount];
}
}
if (dest == null) {
dest = new int[bandUp];
}
/*
* Builds up a RectIter and use it for interpolating all bands.
* There is very few points, so the cost of creating a RectIter
* may be important. But it seems to still lower than query tiles
* many time (which may involve more computation than necessary).
*/
bounds.x = ix - left;
bounds.y = iy - top;
initIterator();
for (; band<bandUp; band++) {
for(int py=bounds.y,yn=bounds.y+bounds.height,j=0; py<yn; py++,j++){
for(int px=bounds.x,xn=bounds.x+bounds.width,i=0; px<xn; px++,i++){
iterator.moveTo(px,py,band);
samples[j][i] = iterator.getSample();
}
}
final int xfrac = (int) ((x-x0) * (1 << interpolation.getSubsampleBitsH()));
final int yfrac = (int) ((y-y0) * (1 << interpolation.getSubsampleBitsV()));
dest[band] = interpolation.interpolate(samples, xfrac, yfrac);
}
return dest;
}
/**
* Interpolates at the specified position. If {@code fallback!=null},
* then {@code dest} <strong>must</strong> have been initialized with
* {@code super.evaluate(...)} prior to invoking this method.
*
* @param x The x position in pixel's coordinates.
* @param y The y position in pixel's coordinates.
* @param dest The destination array, or null.
* @param band The first band's index to interpolate.
* @param bandUp The last band's index+1 to interpolate.
* @return {@code null} if point is outside grid coverage.
*/
private synchronized float[] interpolate(final double x, final double y,
float[] dest, int band, final int bandUp)
{
final double x0 = Math.floor(x);
final double y0 = Math.floor(y);
final int ix = (int)x0;
final int iy = (int)y0;
if (!(ix>=xmin && ix<xmax && iy>=ymin && iy<ymax)) {
if (fallback == null) return null;
if (fallback == this) return dest; // super.evaluate(...) succeed prior to this call.
return fallback.interpolate(x, y, dest, band, bandUp);
}
/*
* Create buffers, if not already created.
*/
float[][] samples = floats;
if (samples == null) {
final int rowCount = interpolation.getHeight();
final int colCount = interpolation.getWidth();
floats = samples = new float[rowCount][];
for (int i=0; i<rowCount; i++) {
samples[i] = new float[colCount];
}
}
if (dest == null) {
dest = new float[bandUp];
}
/*
* Builds up a RectIter and use it for interpolating all bands.
* There is very few points, so the cost of creating a RectIter
* may be important. But it seems to still lower than query tiles
* many time (which may involve more computation than necessary).
*/
bounds.x = ix - left;
bounds.y = iy - top;
initIterator();
for (; band<bandUp; band++) {
for(int py=bounds.y,yn=bounds.y+bounds.height,j=0; py<yn; py++,j++){
for(int px=bounds.x,xn=bounds.x+bounds.width,i=0; px<xn; px++,i++){
iterator.moveTo(px,py,band);
samples[j][i] = iterator.getSampleFloat();
}
}
float dx = (float)(x-x0); if (dx==1) dx=ONE_EPSILON;
float dy = (float)(y-y0); if (dy==1) dy=ONE_EPSILON;
final float value = interpolation.interpolate(samples, dx, dy);
if (Float.isNaN(value)) {
if (fallback == this) continue; // 'dest' was set by 'super.evaluate(...)'.
if (fallback != null) {
fallback.interpolate(x, y, dest, band, band+1);
continue;
}
// If no fallback was specified, then 'dest' is not required to
// have been initialized. It may contains random value. Set it
// to the NaN value...
}
dest[band] = value;
}
return dest;
}
/**
* Interpolate at the specified position. If {@code fallback!=null},
* then {@code dest} <strong>must</strong> have been initialized with
* {@code super.evaluate(...)} prior to invoking this method.
*
* @param x The x position in pixel's coordinates.
* @param y The y position in pixel's coordinates.
* @param dest The destination array, or null.
* @param band The first band's index to interpolate.
* @param bandUp The last band's index+1 to interpolate.
* @return {@code null} if point is outside grid coverage.
*/
private synchronized double[] interpolate(final double x, final double y,
double[] dest, int band, final int bandUp)
{
final double x0 = Math.floor(x);
final double y0 = Math.floor(y);
final int ix = (int)x0;
final int iy = (int)y0;
if (!(ix>=xmin && ix<xmax && iy>=ymin && iy<ymax)) {
if (fallback == null) return null;
if (fallback == this) return dest; // super.evaluate(...) succeed prior to this call.
return fallback.interpolate(x, y, dest, band, bandUp);
}
/*
* Creates buffers, if not already created.
*/
double[][] samples = doubles;
if (samples == null) {
final int rowCount = interpolation.getHeight();
final int colCount = interpolation.getWidth();
doubles = samples = new double[rowCount][];
for (int i=0; i<rowCount; i++) {
samples[i] = new double[colCount];
}
}
if (dest == null) {
dest = new double[bandUp];
}
/*
* Builds up a RectIter and use it for interpolating all bands.
* There is very few points, so the cost of creating a RectIter
* may be important. But it seems to still lower than query tiles
* many time (which may involve more computation than necessary).
*/
bounds.x = ix - left;
bounds.y = iy - top;
initIterator();
for (; band<bandUp; band++) {
for(int py=bounds.y,yn=bounds.y+bounds.height,j=0; py<yn; py++,j++){
for(int px=bounds.x,xn=bounds.x+bounds.width,i=0; px<xn; px++,i++){
iterator.moveTo(px,py,band);
samples[j][i] = iterator.getSampleDouble();
}
}
float dx = (float)(x-x0); if (dx==1) dx=ONE_EPSILON;
float dy = (float)(y-y0); if (dy==1) dy=ONE_EPSILON;
final double value = interpolation.interpolate(samples, dx, dy);
if (Double.isNaN(value)) {
if (fallback == this) continue; // 'dest' was set by 'super.evaluate(...)'.
if (fallback != null) {
fallback.interpolate(x, y, dest, band, band+1);
continue;
}
// If no fallback was specified, then 'dest' is not required to
// have been initialized. It may contains random value. Set it
// to the NaN value...
}
dest[band] = value;
}
return dest;
}
}