[SEDONA-460] Add RS_Tile and RS_TileExplode

common/src/main/java/org/apache/sedona/common/raster/RasterConstructors.java

@@ -16,7 +16,9 @@
 import org.apache.sedona.common.FunctionsGeoTools;
 import org.apache.sedona.common.raster.inputstream.ByteArrayImageInputStream;
 import org.apache.sedona.common.raster.netcdf.NetCdfReader;
+import org.apache.sedona.common.utils.ImageUtils;
 import org.apache.sedona.common.utils.RasterUtils;
+import org.geotools.coverage.GridSampleDimension;
 import org.geotools.coverage.grid.GridCoverage2D;
 import org.geotools.coverage.grid.GridEnvelope2D;
 import org.geotools.coverage.grid.GridGeometry2D;
@@ -36,6 +38,7 @@
 import org.locationtech.jts.geom.Geometry;
 import org.opengis.feature.simple.SimpleFeature;
 import org.opengis.feature.simple.SimpleFeatureType;
+import org.opengis.metadata.spatial.PixelOrientation;
 import org.opengis.referencing.FactoryException;
 import org.opengis.referencing.crs.CoordinateReferenceSystem;
 import org.opengis.referencing.datum.PixelInCell;
@@ -44,6 +47,9 @@
 import ucar.nc2.NetcdfFiles;
 
 import javax.media.jai.RasterFactory;
+import java.awt.Rectangle;
+import java.awt.image.Raster;
+import java.awt.image.RenderedImage;
 import java.awt.image.WritableRaster;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -380,4 +386,166 @@ public static GridCoverage2D makeNonEmptyRaster(int numBands, String bandDataTyp
                 transform, crs, null);
         return RasterUtils.create(raster, gridGeometry, null);
     }
+
+
+    public static class Tile {
+        private final int tileX;
+        private final int tileY;
+        private final GridCoverage2D coverage;
+
+        public Tile(int tileX, int tileY, GridCoverage2D coverage) {
+            this.tileX = tileX;
+            this.tileY = tileY;
+            this.coverage = coverage;
+        }
+
+        public int getTileX() {
+            return tileX;
+        }
+
+        public int getTileY() {
+            return tileY;
+        }
+
+        public GridCoverage2D getCoverage() {
+            return coverage;
+        }
+    }
+
+    /**
+     * Generate tiles from a grid coverage
+     * @param gridCoverage2D the grid coverage
+     * @param bandIndices the indices of the bands to select (1-based), can be null or empty to include all the bands.
+     * @param tileWidth the width of the tiles
+     * @param tileHeight the height of the tiles
+     * @param padWithNoData whether to pad the tiles with no data value
+     * @param padNoDataValue the no data value for padded tiles, only used when padWithNoData is true.
+     *                       If the value is NaN, the no data value of the original band will be used.
+     * @return the tiles
+     */
+    public static Tile[] generateTiles(GridCoverage2D gridCoverage2D, int[] bandIndices, int tileWidth, int tileHeight,
+                                       boolean padWithNoData, double padNoDataValue) {
+        int numBands = gridCoverage2D.getNumSampleDimensions();
+        if (bandIndices == null || bandIndices.length == 0) {
+            // Select all the bands
+            bandIndices = new int[numBands];
+            for (int i = 0; i < numBands; i++) {
+                bandIndices[i] = i + 1;
+            }
+        } else {
+            // Check the band indices
+            for (int bandIndex : bandIndices) {
+                if (bandIndex <= 0 || bandIndex > numBands) {
+                    throw new IllegalArgumentException(
+                            String.format("Provided band index %d is not present in the raster", bandIndex));
+                }
+            }
+        }
+        return doGenerateTiles(gridCoverage2D, bandIndices, tileWidth, tileHeight, padWithNoData, padNoDataValue);
+    }
+
+    /**
+     * Generate tiles from an in-db grid coverage. The generated tiles are also in-db grid coverages. Pixel data will be
+     * copied into the tiles.
+     * @param gridCoverage2D the in-db grid coverage
+     * @param bandIndices the indices of the bands to select (1-based)
+     * @param tileWidth the width of the tiles
+     * @param tileHeight the height of the tiles
+     * @param padWithNoData whether to pad the tiles with no data value
+     * @param padNoDataValue the no data value for padded tiles, only used when padWithNoData is true.
+     *                       If the value is NaN, the no data value of the original band will be used.
+     * @return the tiles
+     */
+    private static Tile[] doGenerateTiles(GridCoverage2D gridCoverage2D, int[] bandIndices, int tileWidth,
+                                          int tileHeight, boolean padWithNoData, double padNoDataValue) {
+        AffineTransform2D affine = RasterUtils.getAffineTransform(gridCoverage2D, PixelOrientation.CENTER);
+        RenderedImage image = gridCoverage2D.getRenderedImage();
+        double[] noDataValues = new double[bandIndices.length];
+        for (int i = 0; i < bandIndices.length; i++) {
+            noDataValues[i] = RasterUtils.getNoDataValue(gridCoverage2D.getSampleDimension(bandIndices[i] - 1));
+        }
+        int width = image.getWidth();
+        int height = image.getHeight();
+        int numTileX = (int) Math.ceil((double) width / tileWidth);
+        int numTileY = (int) Math.ceil((double) height / tileHeight);
+        Tile[] tiles = new Tile[numTileX * numTileY];
+        for (int tileY = 0; tileY < numTileY; tileY++) {
+            for (int tileX = 0; tileX < numTileX; tileX++) {
+                int x0 = tileX * tileWidth;
+                int y0 = tileY * tileHeight;
+
+                // Rect to copy from the original image
+                int rectWidth = Math.min(tileWidth, width - x0);
+                int rectHeight = Math.min(tileHeight, height - y0);
+
+                // If we don't pad with no data, the tiles on the boundary may have a different size
+                int currentTileWidth = padWithNoData? tileWidth: rectWidth;
+                int currentTileHeight = padWithNoData? tileHeight: rectHeight;
+                boolean needPadding = padWithNoData && (rectWidth < tileWidth || rectHeight < tileHeight);
+
+                // Create a new affine transformation for this tile
+                AffineTransform2D tileAffine = RasterUtils.translateAffineTransform(affine, x0, y0);
+                GridGeometry2D gridGeometry2D = new GridGeometry2D(
+                        new GridEnvelope2D(0, 0, currentTileWidth, currentTileHeight),
+                        PixelInCell.CELL_CENTER,
+                        tileAffine, gridCoverage2D.getCoordinateReferenceSystem(), null);
+
+                // Prepare a new image for this tile, and copy the data from the original image
+                WritableRaster raster = RasterFactory.createBandedRaster(
+                        image.getSampleModel().getDataType(), currentTileWidth, currentTileHeight,
+                        bandIndices.length, null);
+                GridSampleDimension[] sampleDimensions = new GridSampleDimension[bandIndices.length];
+                Raster sourceRaster = image.getData(new Rectangle(x0, y0, rectWidth, rectHeight));
+                for (int k = 0; k < bandIndices.length; k++) {
+                    int bandIndex = bandIndices[k] - 1;
+
+                    // Copy sample dimensions from source bands, and pad with no data value if necessary
+                    GridSampleDimension sampleDimension = gridCoverage2D.getSampleDimension(bandIndex);
+                    double noDataValue = noDataValues[k];
+                    if (needPadding && !Double.isNaN(padNoDataValue)) {
+                        sampleDimension = RasterUtils.createSampleDimensionWithNoDataValue(sampleDimension, padNoDataValue);
+                        noDataValue = padNoDataValue;
+                    }
+                    sampleDimensions[k] = sampleDimension;
+
+                    // Copy data from original image to tile image
+                    ImageUtils.copyRasterWithPadding(sourceRaster, bandIndex, raster, k, noDataValue);
+                }
+
+                GridCoverage2D tile = RasterUtils.create(raster, gridGeometry2D, sampleDimensions);
+                tiles[tileY * numTileX + tileX] = new Tile(tileX, tileY, tile);
+            }
+        }
+
+        return tiles;
+    }
+
+    public static GridCoverage2D[] rsTile(GridCoverage2D gridCoverage2D, int[] bandIndices, int tileWidth, int tileHeight,
+                                          boolean padWithNoData, Double padNoDataValue) {
+        if (gridCoverage2D == null) {
+            return null;
+        }
+        if (padNoDataValue == null) {
+            padNoDataValue = Double.NaN;
+        }
+        Tile[] tiles = generateTiles(gridCoverage2D, bandIndices, tileWidth, tileHeight, padWithNoData, padNoDataValue);
+        GridCoverage2D[] result = new GridCoverage2D[tiles.length];
+        for (int i = 0; i < tiles.length; i++) {
+            result[i] = tiles[i].getCoverage();
+        }
+        return result;
+    }
+
+    public static GridCoverage2D[] rsTile(GridCoverage2D gridCoverage2D, int[] bandIndices, int tileWidth, int tileHeight,
+                                          boolean padWithNoData) {
+        return rsTile(gridCoverage2D, bandIndices, tileWidth, tileHeight, padWithNoData, Double.NaN);
+    }
+
+    public static GridCoverage2D[] rsTile(GridCoverage2D gridCoverage2D, int[] bandIndices, int tileWidth, int tileHeight) {
+        return rsTile(gridCoverage2D, bandIndices, tileWidth, tileHeight, false);
+    }
+
+    public static GridCoverage2D[] rsTile(GridCoverage2D gridCoverage2D, int tileWidth, int tileHeight) {
+        return rsTile(gridCoverage2D, null, tileWidth, tileHeight);
+    }
 }

common/src/main/java/org/apache/sedona/common/utils/ImageUtils.java

@@ -0,0 +1,68 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.sedona.common.utils;
+
+import java.awt.image.Raster;
+import java.awt.image.WritableRaster;
+
+/**
+ * Utility functions for image processing.
+ */
+public class ImageUtils {
+    private ImageUtils() {}
+
+    /**
+     * Copy a raster to another raster, with padding if necessary.
+     * @param sourceRaster the source raster
+     * @param sourceBand the source band
+     * @param destRaster the destination raster, which must not be smaller than the source raster
+     * @param destBand the destination band
+     * @param padValue the padding value, or NaN if no padding is needed
+     */
+    public static void copyRasterWithPadding(Raster sourceRaster, int sourceBand, WritableRaster destRaster, int destBand, double padValue) {
+        int destWidth = destRaster.getWidth();
+        int destHeight = destRaster.getHeight();
+        int destMinX = destRaster.getMinX();
+        int destMinY = destRaster.getMinY();
+        int sourceWidth = sourceRaster.getWidth();
+        int sourceHeight = sourceRaster.getHeight();
+        int sourceMinX = sourceRaster.getMinX();
+        int sourceMinY = sourceRaster.getMinY();
+        if (sourceWidth > destWidth || sourceHeight > destHeight) {
+            throw new IllegalArgumentException("Source raster is larger than destination raster");
+        }
+
+        // Copy the source raster to the destination raster
+        double[] samples = sourceRaster.getSamples(sourceMinX, sourceMinY, sourceWidth, sourceHeight, sourceBand, (double[]) null);
+        destRaster.setSamples(destMinX, destMinY, sourceWidth, sourceHeight, destBand, samples);
+
+        // Pad the right edge
+        for (int y = destMinY; y < sourceHeight + destMinY; y++) {
+            for (int x = sourceWidth + destMinX; x < destWidth + destMinX; x++) {
+                destRaster.setSample(x, y, destBand, padValue);
+            }
+        }
+        // Pad the bottom edge
+        for (int y = sourceHeight + destMinY; y < destHeight + destMinY; y++) {
+            for (int x = destMinX; x < destWidth + destMinX; x++) {
+                destRaster.setSample(x, y, destBand, padValue);
+            }
+        }
+    }
+}

common/src/main/java/org/apache/sedona/common/utils/RasterUtils.java

@@ -374,6 +374,27 @@ public static AffineTransform2D getAffineTransform(GridCoverage2D raster, PixelO
         return (AffineTransform2D) crsTransform;
     }
 
+    /**
+     * Translate an affine transformation by a given offset.
+     * @param affine the affine transformation
+     * @param offsetX the offset in x direction
+     * @param offsetY the offset in y direction
+     * @return the translated affine transformation
+     */
+    public static AffineTransform2D translateAffineTransform(AffineTransform2D affine, int offsetX, int offsetY) {
+        double ipX = affine.getTranslateX();
+        double ipY = affine.getTranslateY();
+        double scaleX = affine.getScaleX();
+        double scaleY = affine.getScaleY();
+        double skewX = affine.getShearX();
+        double skewY = affine.getShearY();
+
+        // Move the origin using the affine transformation, and leave scale and skew unchanged.
+        double newIpX = ipX + offsetX * scaleX + offsetY * skewX;
+        double newIpY = ipY + offsetX * skewY + offsetY * scaleY;
+        return new AffineTransform2D(scaleX, skewY, skewX, scaleY, newIpX, newIpY);
+    }
+
     public static Point2D getWorldCornerCoordinates(GridCoverage2D raster, int colX, int rowY) throws TransformException {
         return raster.getGridGeometry().getGridToCRS2D(PixelOrientation.UPPER_LEFT).transform(new GridCoordinates2D(colX - 1, rowY - 1), null);
     }