| /* BandCombineOp.java - perform a combination on the bands of a raster |
| Copyright (C) 2004, 2006 Free Software Foundation |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package java.awt.image; |
| |
| import java.awt.RenderingHints; |
| import java.awt.geom.Point2D; |
| import java.awt.geom.Rectangle2D; |
| import java.util.Arrays; |
| |
| /** |
| * Filter Raster pixels by applying a matrix. |
| * |
| * BandCombineOp applies a matrix to each pixel to produce new pixel values. |
| * The width of the matrix must be the same or one more than the number of |
| * bands in the source Raster. If one more, the pixels in the source are |
| * assumed to contain an implicit 1.0 at the end. |
| * |
| * The rows of the matrix are multiplied by the pixel to produce the values |
| * for the destination. Therefore the destination Raster must contain the |
| * same number of bands as the number of rows in the filter matrix. |
| * |
| * This Op assumes that samples are integers; floating point sample types will |
| * be rounded to their nearest integer value during filtering. |
| * |
| * @author Jerry Quinn (jlquinn@optonline.net) |
| */ |
| public class BandCombineOp implements RasterOp |
| { |
| private RenderingHints hints; |
| private float[][] matrix; |
| |
| /** |
| * Construct a BandCombineOp. |
| * |
| * @param matrix The matrix to filter pixels with. |
| * @param hints Rendering hints to apply. Ignored. |
| * @throws ArrayIndexOutOfBoundsException if the matrix is invalid |
| */ |
| public BandCombineOp(float[][] matrix, RenderingHints hints) |
| { |
| this.matrix = new float[matrix.length][]; |
| int width = matrix[0].length; |
| for (int i = 0; i < matrix.length; i++) |
| { |
| this.matrix[i] = new float[width + 1]; |
| for (int j = 0; j < width; j++) |
| this.matrix[i][j] = matrix[i][j]; |
| |
| // The reference implementation pads the array with a trailing zero... |
| this.matrix[i][width] = 0; |
| } |
| |
| this.hints = hints; |
| } |
| |
| /** |
| * Filter Raster pixels through a matrix. Applies the Op matrix to source |
| * pixes to produce dest pixels. Each row of the matrix is multiplied by the |
| * src pixel components to produce the dest pixel. If matrix is one more than |
| * the number of bands in the src, the last element is implicitly multiplied |
| * by 1, i.e. added to the sum for that dest component. If dest is null, a |
| * suitable Raster is created. This implementation uses |
| * createCompatibleDestRaster. |
| * |
| * @param src The source Raster. |
| * @param dest The destination Raster, or null. |
| * @throws IllegalArgumentException if the destination raster is incompatible |
| * with the source raster. |
| * @return The filtered Raster. |
| * @see java.awt.image.RasterOp#filter(java.awt.image.Raster, |
| * java.awt.image.WritableRaster) |
| */ |
| public WritableRaster filter(Raster src, WritableRaster dest) { |
| if (dest == null) |
| dest = createCompatibleDestRaster(src); |
| else if (dest.getNumBands() != src.getNumBands() |
| || dest.getTransferType() != src.getTransferType()) |
| throw new IllegalArgumentException("Destination raster is incompatible with source raster"); |
| |
| // Filter the pixels |
| int[] spix = new int[matrix[0].length - 1]; |
| int[] spix2 = new int[matrix[0].length - 1]; |
| int[] dpix = new int[matrix.length]; |
| for (int y = src.getMinY(); y < src.getHeight() + src.getMinY(); y++) |
| for (int x = src.getMinX(); x < src.getWidth() + src.getMinX(); x++) |
| { |
| // In case matrix rows have implicit translation |
| spix[spix.length - 1] = 1; |
| src.getPixel(x, y, spix); |
| |
| // Do not re-calculate if pixel is identical to the last one |
| // (ie, blocks of the same colour) |
| if (!Arrays.equals(spix, spix2)) |
| { |
| System.arraycopy(spix, 0, spix2, 0, spix.length); |
| for (int i = 0; i < matrix.length; i++) |
| { |
| dpix[i] = 0; |
| for (int j = 0; j < matrix[0].length - 1; j++) |
| dpix[i] += spix[j] * (int)matrix[i][j]; |
| } |
| } |
| dest.setPixel(x, y, dpix); |
| } |
| |
| return dest; |
| } |
| |
| /* (non-Javadoc) |
| * @see java.awt.image.RasterOp#getBounds2D(java.awt.image.Raster) |
| */ |
| public final Rectangle2D getBounds2D(Raster src) |
| { |
| return src.getBounds(); |
| } |
| |
| /** |
| * Creates a new WritableRaster that can be used as the destination for this |
| * Op. The number of bands in the source raster must equal the number of rows |
| * in the op matrix, which must also be equal to either the number of columns |
| * or (columns - 1) in the matrix. |
| * |
| * @param src The source raster. |
| * @return A compatible raster. |
| * @see java.awt.image.RasterOp#createCompatibleDestRaster(java.awt.image.Raster) |
| * @throws IllegalArgumentException if the raster is incompatible with the |
| * matrix. |
| */ |
| public WritableRaster createCompatibleDestRaster(Raster src) |
| { |
| // Destination raster must have same number of bands as source |
| if (src.getNumBands() != matrix.length) |
| throw new IllegalArgumentException("Number of rows in matrix specifies an " |
| + "incompatible number of bands"); |
| |
| // We use -1 and -2 because we previously padded the rows with a trailing 0 |
| if (src.getNumBands() != matrix[0].length - 1 |
| && src.getNumBands() != matrix[0].length - 2) |
| throw new IllegalArgumentException("Incompatible number of bands: " |
| + "the number of bands in the raster must equal the number of " |
| + "columns in the matrix, optionally minus one"); |
| |
| return src.createCompatibleWritableRaster(); |
| } |
| |
| /** |
| * Return corresponding destination point for source point. Because this is |
| * not a geometric operation, it simply returns a copy of the source. |
| * |
| * @param src The source point. |
| * @param dst The destination point. |
| * @return dst The destination point. |
| * @see java.awt.image.RasterOp#getPoint2D(java.awt.geom.Point2D, |
| *java.awt.geom.Point2D) |
| */ |
| public final Point2D getPoint2D(Point2D src, Point2D dst) |
| { |
| if (dst == null) |
| return (Point2D)src.clone(); |
| |
| dst.setLocation(src); |
| return dst; |
| } |
| |
| /* (non-Javadoc) |
| * @see java.awt.image.RasterOp#getRenderingHints() |
| */ |
| public final RenderingHints getRenderingHints() |
| { |
| return hints; |
| } |
| |
| /** |
| * Return the matrix used in this operation. |
| * |
| * @return The matrix used in this operation. |
| */ |
| public final float[][] getMatrix() |
| { |
| return matrix; |
| } |
| |
| } |