386 lines
14 KiB
Java
386 lines
14 KiB
Java
/* Copyright (C) 2004, 2006 Free Software Foundation
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.awt.image;
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import java.awt.RenderingHints;
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import java.awt.geom.Point2D;
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import java.awt.geom.Rectangle2D;
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import java.util.Arrays;
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/**
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* RescaleOp is a filter that changes each pixel by a scaling factor and offset.
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*
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* For filtering Rasters, either one scaling factor and offset can be specified,
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* which will be applied to all bands; or a scaling factor and offset can be
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* specified for each band.
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*
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* For BufferedImages, the scaling may apply to both color and alpha components.
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* If only one scaling factor is provided, or if the number of factors provided
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* equals the number of color components, the scaling is performed on all color
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* components. Otherwise, the scaling is performed on all components including
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* alpha. Alpha premultiplication is ignored.
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*
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* After filtering, if color conversion is necessary, the conversion happens,
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* taking alpha premultiplication into account.
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*
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* @author Jerry Quinn (jlquinn@optonline.net)
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* @author Francis Kung (fkung@redhat.com)
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*/
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public class RescaleOp implements BufferedImageOp, RasterOp
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{
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private float[] scale;
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private float[] offsets;
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private RenderingHints hints = null;
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/**
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* Create a new RescaleOp object using the given scale factors and offsets.
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*
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* The length of the arrays must be equal to the number of bands (or number of
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* data or color components) of the raster/image that this Op will be used on,
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* otherwise an IllegalArgumentException will be thrown when calling the
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* filter method.
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*
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* @param scaleFactors an array of scale factors.
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* @param offsets an array of offsets.
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* @param hints any rendering hints to use (can be null).
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* @throws NullPointerException if the scaleFactors or offsets array is null.
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*/
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public RescaleOp(float[] scaleFactors,
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float[] offsets,
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RenderingHints hints)
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{
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int length = Math.min(scaleFactors.length, offsets.length);
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scale = new float[length];
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System.arraycopy(scaleFactors, 0, this.scale, 0, length);
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this.offsets = new float[length];
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System.arraycopy(offsets, 0, this.offsets, 0, length);
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this.hints = hints;
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}
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/**
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* Create a new RescaleOp object using the given scale factor and offset.
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*
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* The same scale factor and offset will be used on all bands/components.
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*
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* @param scaleFactor the scale factor to use.
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* @param offset the offset to use.
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* @param hints any rendering hints to use (can be null).
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*/
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public RescaleOp(float scaleFactor,
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float offset,
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RenderingHints hints)
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{
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scale = new float[]{ scaleFactor };
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offsets = new float[]{offset};
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this.hints = hints;
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}
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/**
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* Returns the scaling factors. This method accepts an optional array, which
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* will be used to store the factors if not null (this avoids allocating a
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* new array). If this array is too small to hold all the scaling factors,
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* the array will be filled and the remaining factors discarded.
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*
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* @param scaleFactors array to store the scaling factors in (can be null).
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* @return an array of scaling factors.
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*/
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public final float[] getScaleFactors(float[] scaleFactors)
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{
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if (scaleFactors == null)
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scaleFactors = new float[scale.length];
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System.arraycopy(scale, 0, scaleFactors, 0, Math.min(scale.length,
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scaleFactors.length));
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return scaleFactors;
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}
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/**
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* Returns the offsets. This method accepts an optional array, which
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* will be used to store the offsets if not null (this avoids allocating a
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* new array). If this array is too small to hold all the offsets, the array
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* will be filled and the remaining factors discarded.
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*
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* @param offsets array to store the offsets in (can be null).
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* @return an array of offsets.
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*/
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public final float[] getOffsets(float[] offsets)
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{
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if (offsets == null)
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offsets = new float[this.offsets.length];
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System.arraycopy(this.offsets, 0, offsets, 0, Math.min(this.offsets.length,
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offsets.length));
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return offsets;
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}
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/**
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* Returns the number of scaling factors / offsets.
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*
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* @return the number of scaling factors / offsets.
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*/
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public final int getNumFactors()
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{
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return scale.length;
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}
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/* (non-Javadoc)
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* @see java.awt.image.BufferedImageOp#getRenderingHints()
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*/
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public final RenderingHints getRenderingHints()
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{
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return hints;
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}
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/**
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* Converts the source image using the scale factors and offsets specified in
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* the constructor. The resulting image is stored in the destination image if
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* one is provided; otherwise a new BufferedImage is created and returned.
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*
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* The source image cannot use an IndexColorModel, and the destination image
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* (if one is provided) must have the same size.
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*
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* If the final value of a sample is beyond the range of the color model, it
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* will be clipped to the appropriate maximum / minimum.
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*
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* @param src The source image.
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* @param dst The destination image.
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* @throws IllegalArgumentException if the rasters and/or color spaces are
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* incompatible.
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* @return The rescaled image.
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*/
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public final BufferedImage filter(BufferedImage src, BufferedImage dst)
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{
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// Initial checks
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if (scale.length != 1
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&& scale.length != src.getColorModel().getNumComponents()
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&& (scale.length != src.getColorModel().getNumColorComponents()))
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throw new IllegalArgumentException("Source image has wrong number of "
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+ "bands for these scaling factors.");
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if (dst == null)
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dst = createCompatibleDestImage(src, null);
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else if (src.getHeight() != dst.getHeight()
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|| src.getWidth() != dst.getWidth())
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throw new IllegalArgumentException("Source and destination images are "
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+ "different sizes.");
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// Prepare for possible colorspace conversion
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BufferedImage dst2 = dst;
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if (dst.getColorModel().getColorSpace().getType() != src.getColorModel().getColorSpace().getType())
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dst2 = createCompatibleDestImage(src, src.getColorModel());
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// Figure out how many bands to scale
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int numBands = scale.length;
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if (scale.length == 1)
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numBands = src.getColorModel().getNumColorComponents();
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boolean[] bands = new boolean[numBands];
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// this assumes the alpha, if present, is the last band
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Arrays.fill(bands, true);
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// Perform rescaling
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filter(src.getRaster(), dst2.getRaster(), bands);
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// Copy alpha band if needed (ie if it exists and wasn't scaled)
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// NOTE: This assumes the alpha component is the last band!
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if (src.getColorModel().hasAlpha()
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&& numBands == src.getColorModel().getNumColorComponents())
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{
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dst2.getRaster().setSamples(0, 0, src.getWidth(), src.getHeight(),
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numBands,
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src.getRaster().getSamples(0, 0,
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src.getWidth(),
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src.getHeight(),
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numBands,
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(int[]) null));
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}
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// Perform colorspace conversion if needed
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if (dst != dst2)
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new ColorConvertOp(hints).filter(dst2, dst);
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return dst;
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}
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/* (non-Javadoc)
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* @see java.awt.image.RasterOp#filter(java.awt.image.Raster, java.awt.image.WritableRaster)
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*/
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public final WritableRaster filter(Raster src, WritableRaster dest)
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{
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// Required sanity checks
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if (scale.length != 1 && scale.length != src.numBands)
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throw new IllegalArgumentException("Number of rasters is incompatible "
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+ "with the number of scaling "
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+ "factors provided.");
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if (dest == null)
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dest = src.createCompatibleWritableRaster();
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else if (src.getHeight() != dest.getHeight()
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|| src.getWidth() != dest.getWidth())
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throw new IllegalArgumentException("Source and destination rasters are "
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+ "different sizes.");
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else if (src.numBands != dest.numBands)
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throw new IllegalArgumentException("Source and destination rasters "
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+ "are incompatible.");
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// Filter all bands
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boolean[] bands = new boolean[src.getNumBands()];
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Arrays.fill(bands, true);
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return filter(src, dest, bands);
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}
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/**
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* Perform raster-based filtering on a selected number of bands.
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*
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* The length of the bands array should equal the number of bands; a true
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* element indicates filtering should happen on the corresponding band, while
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* a false element will skip the band.
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*
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* The rasters are assumed to be compatible and non-null.
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*
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* @param src the source raster.
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* @param dest the destination raster.
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* @param bands an array indicating which bands to filter.
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* @throws NullPointerException if any parameter is null.
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* @throws ArrayIndexOutOfBoundsException if the bands array is too small.
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* @return the destination raster.
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*/
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private WritableRaster filter(Raster src, WritableRaster dest, boolean[] bands)
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{
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int[] values = new int[src.getHeight() * src.getWidth()];
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float scaleFactor, offset;
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// Find max sample value, to be used for clipping later
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int[] maxValue = src.getSampleModel().getSampleSize();
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for (int i = 0; i < maxValue.length; i++)
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maxValue[i] = (int)Math.pow(2, maxValue[i]) - 1;
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// TODO: can this be optimized further?
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// Filter all samples of all requested bands
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for (int band = 0; band < bands.length; band++)
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if (bands[band])
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{
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values = src.getSamples(src.getMinX(), src.getMinY(), src.getWidth(),
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src.getHeight(), band, values);
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if (scale.length == 1)
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{
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scaleFactor = scale[0];
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offset = offsets[0];
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}
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else
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{
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scaleFactor = scale[band];
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offset = offsets[band];
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}
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for (int i = 0; i < values.length; i++)
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{
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values[i] = (int) (values[i] * scaleFactor + offset);
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// Clip if needed
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if (values[i] < 0)
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values[i] = 0;
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if (values[i] > maxValue[band])
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values[i] = maxValue[band];
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}
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dest.setSamples(dest.getMinX(), dest.getMinY(), dest.getWidth(),
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dest.getHeight(), band, values);
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}
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return dest;
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}
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/*
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* (non-Javadoc)
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*
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* @see java.awt.image.BufferedImageOp#createCompatibleDestImage(java.awt.image.BufferedImage,
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* java.awt.image.ColorModel)
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*/
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public BufferedImage createCompatibleDestImage(BufferedImage src,
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ColorModel dstCM)
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{
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if (dstCM == null)
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return new BufferedImage(src.getWidth(), src.getHeight(), src.getType());
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return new BufferedImage(dstCM,
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src.getRaster().createCompatibleWritableRaster(),
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src.isAlphaPremultiplied(), null);
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}
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/* (non-Javadoc)
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* @see java.awt.image.RasterOp#createCompatibleDestRaster(java.awt.image.Raster)
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*/
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public WritableRaster createCompatibleDestRaster(Raster src)
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{
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return src.createCompatibleWritableRaster();
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}
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/* (non-Javadoc)
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* @see java.awt.image.BufferedImageOp#getBounds2D(java.awt.image.BufferedImage)
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*/
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public final Rectangle2D getBounds2D(BufferedImage src)
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{
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return src.getRaster().getBounds();
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}
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/* (non-Javadoc)
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* @see java.awt.image.RasterOp#getBounds2D(java.awt.image.Raster)
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*/
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public final Rectangle2D getBounds2D(Raster src)
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{
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return src.getBounds();
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}
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/* (non-Javadoc)
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* @see java.awt.image.BufferedImageOp#getPoint2D(java.awt.geom.Point2D, java.awt.geom.Point2D)
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*/
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public final Point2D getPoint2D(Point2D src, Point2D dst)
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{
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if (dst == null)
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dst = (Point2D) src.clone();
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else
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dst.setLocation(src);
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return dst;
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}
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}
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