Java tutorial
/* * Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.awt.image; import java.awt.GraphicsEnvironment; import java.awt.color.ICC_Profile; import java.awt.geom.Rectangle2D; import java.awt.Rectangle; import java.awt.geom.Point2D; import java.awt.RenderingHints; import sun.awt.image.ImagingLib; import java.util.Arrays; /** * This class performs an arbitrary linear combination of the bands * in a {@code Raster}, using a specified matrix. * <p> * The width of the matrix must be equal to the number of bands in the * source {@code Raster}, optionally plus one. If there is one more * column in the matrix than the number of bands, there is an implied 1 at the * end of the vector of band samples representing a pixel. The height * of the matrix must be equal to the number of bands in the destination. * <p> * For example, a 3-banded {@code Raster} might have the following * transformation applied to each pixel in order to invert the second band of * the {@code Raster}. * <pre> * [ 1.0 0.0 0.0 0.0 ] [ b1 ] * [ 0.0 -1.0 0.0 255.0 ] x [ b2 ] * [ 0.0 0.0 1.0 0.0 ] [ b3 ] * [ 1 ] * </pre> * * <p> * Note that the source and destination can be the same object. */ public class BandCombineOp implements RasterOp { float[][] matrix; int nrows = 0; int ncols = 0; RenderingHints hints; /** * Constructs a {@code BandCombineOp} with the specified matrix. * The width of the matrix must be equal to the number of bands in * the source {@code Raster}, optionally plus one. If there is one * more column in the matrix than the number of bands, there is an implied * 1 at the end of the vector of band samples representing a pixel. The * height of the matrix must be equal to the number of bands in the * destination. * <p> * The first subscript is the row index and the second * is the column index. This operation uses none of the currently * defined rendering hints; the {@code RenderingHints} argument can be * null. * * @param matrix The matrix to use for the band combine operation. * @param hints The {@code RenderingHints} object for this operation. * Not currently used so it can be null. */ public BandCombineOp(float[][] matrix, RenderingHints hints) { nrows = matrix.length; ncols = matrix[0].length; this.matrix = new float[nrows][]; for (int i = 0; i < nrows; i++) { /* Arrays.copyOf is forgiving of the source array being * too short, but it is also faster than other cloning * methods, so we provide our own protection for short * matrix rows. */ if (ncols > matrix[i].length) { throw new IndexOutOfBoundsException("row " + i + " too short"); } this.matrix[i] = Arrays.copyOf(matrix[i], ncols); } this.hints = hints; } /** * Returns a copy of the linear combination matrix. * * @return The matrix associated with this band combine operation. */ public final float[][] getMatrix() { float[][] ret = new float[nrows][]; for (int i = 0; i < nrows; i++) { ret[i] = Arrays.copyOf(matrix[i], ncols); } return ret; } /** * Transforms the {@code Raster} using the matrix specified in the * constructor. An {@code IllegalArgumentException} may be thrown if * the number of bands in the source or destination is incompatible with * the matrix. See the class comments for more details. * <p> * If the destination is null, it will be created with a number of bands * equalling the number of rows in the matrix. No exception is thrown * if the operation causes a data overflow. * * @param src The {@code Raster} to be filtered. * @param dst The {@code Raster} in which to store the results * of the filter operation. * * @return The filtered {@code Raster}. * * @throws IllegalArgumentException If the number of bands in the * source or destination is incompatible with the matrix. */ public WritableRaster filter(Raster src, WritableRaster dst) { int nBands = src.getNumBands(); if (ncols != nBands && ncols != (nBands + 1)) { throw new IllegalArgumentException("Number of columns in the " + "matrix (" + ncols + ") must be equal to the number" + " of bands ([+1]) in src (" + nBands + ")."); } if (dst == null) { dst = createCompatibleDestRaster(src); } else if (nrows != dst.getNumBands()) { throw new IllegalArgumentException("Number of rows in the " + "matrix (" + nrows + ") must be equal to the number" + " of bands ([+1]) in dst (" + nBands + ")."); } if (ImagingLib.filter(this, src, dst) != null) { return dst; } int[] pixel = null; int[] dstPixel = new int[dst.getNumBands()]; float accum; int sminX = src.getMinX(); int sY = src.getMinY(); int dminX = dst.getMinX(); int dY = dst.getMinY(); int sX; int dX; if (ncols == nBands) { for (int y = 0; y < src.getHeight(); y++, sY++, dY++) { dX = dminX; sX = sminX; for (int x = 0; x < src.getWidth(); x++, sX++, dX++) { pixel = src.getPixel(sX, sY, pixel); for (int r = 0; r < nrows; r++) { accum = 0.f; for (int c = 0; c < ncols; c++) { accum += matrix[r][c] * pixel[c]; } dstPixel[r] = (int) accum; } dst.setPixel(dX, dY, dstPixel); } } } else { // Need to add constant for (int y = 0; y < src.getHeight(); y++, sY++, dY++) { dX = dminX; sX = sminX; for (int x = 0; x < src.getWidth(); x++, sX++, dX++) { pixel = src.getPixel(sX, sY, pixel); for (int r = 0; r < nrows; r++) { accum = 0.f; for (int c = 0; c < nBands; c++) { accum += matrix[r][c] * pixel[c]; } dstPixel[r] = (int) (accum + matrix[r][nBands]); } dst.setPixel(dX, dY, dstPixel); } } } return dst; } /** * Returns the bounding box of the transformed destination. Since * this is not a geometric operation, the bounding box is the same for * the source and destination. * An {@code IllegalArgumentException} may be thrown if the number of * bands in the source is incompatible with the matrix. See * the class comments for more details. * * @param src The {@code Raster} to be filtered. * * @return The {@code Rectangle2D} representing the destination * image's bounding box. * * @throws IllegalArgumentException If the number of bands in the source * is incompatible with the matrix. */ public final Rectangle2D getBounds2D(Raster src) { return src.getBounds(); } /** * Creates a zeroed destination {@code Raster} with the correct size * and number of bands. * An {@code IllegalArgumentException} may be thrown if the number of * bands in the source is incompatible with the matrix. See * the class comments for more details. * * @param src The {@code Raster} to be filtered. * * @return The zeroed destination {@code Raster}. */ public WritableRaster createCompatibleDestRaster(Raster src) { int nBands = src.getNumBands(); if ((ncols != nBands) && (ncols != (nBands + 1))) { throw new IllegalArgumentException("Number of columns in the " + "matrix (" + ncols + ") must be equal to the number" + " of bands ([+1]) in src (" + nBands + ")."); } if (src.getNumBands() == nrows) { return src.createCompatibleWritableRaster(); } else { throw new IllegalArgumentException( "Don't know how to create a " + " compatible Raster with " + nrows + " bands."); } } /** * Returns the location of the corresponding destination point given a * point in the source {@code Raster}. If {@code dstPt} is * specified, it is used to hold the return value. * Since this is not a geometric operation, the point returned * is the same as the specified {@code srcPt}. * * @param srcPt The {@code Point2D} that represents the point in * the source {@code Raster} * @param dstPt The {@code Point2D} in which to store the result. * * @return The {@code Point2D} in the destination image that * corresponds to the specified point in the source image. */ public final Point2D getPoint2D(Point2D srcPt, Point2D dstPt) { if (dstPt == null) { dstPt = new Point2D.Float(); } dstPt.setLocation(srcPt.getX(), srcPt.getY()); return dstPt; } /** * Returns the rendering hints for this operation. * * @return The {@code RenderingHints} object associated with this * operation. Returns null if no hints have been set. */ public final RenderingHints getRenderingHints() { return hints; } }