META-INF.modules.java.desktop.classes.java.awt.image.RescaleOp Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2018, 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.color.ColorSpace;
import java.awt.geom.Rectangle2D;
import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.geom.Point2D;
import java.awt.RenderingHints;
import sun.awt.image.ImagingLib;
/**
* This class performs a pixel-by-pixel rescaling of the data in the
* source image by multiplying the sample values for each pixel by a scale
* factor and then adding an offset. The scaled sample values are clipped
* to the minimum/maximum representable in the destination image.
*
* The pseudo code for the rescaling operation is as follows:
*
*for each pixel from Source object {
* for each band/component of the pixel {
* dstElement = (srcElement*scaleFactor) + offset
* }
*}
*
*
* For Rasters, rescaling operates on bands. The number of
* sets of scaling constants may be one, in which case the same constants
* are applied to all bands, or it must equal the number of Source
* Raster bands.
*
* For BufferedImages, rescaling operates on color and alpha components.
* The number of sets of scaling constants may be one, in which case the
* same constants are applied to all color (but not alpha) components.
* Otherwise, the number of sets of scaling constants may
* equal the number of Source color components, in which case no
* rescaling of the alpha component (if present) is performed.
* If neither of these cases apply, the number of sets of scaling constants
* must equal the number of Source color components plus alpha components,
* in which case all color and alpha components are rescaled.
*
* BufferedImage sources with premultiplied alpha data are treated in the same
* manner as non-premultiplied images for purposes of rescaling. That is,
* the rescaling is done per band on the raw data of the BufferedImage source
* without regard to whether the data is premultiplied. If a color conversion
* is required to the destination ColorModel, the premultiplied state of
* both source and destination will be taken into account for this step.
*
* Images with an IndexColorModel cannot be rescaled.
*
* If a RenderingHints object is specified in the constructor, the
* color rendering hint and the dithering hint may be used when color
* conversion is required.
*
* Note that in-place operation is allowed (i.e. the source and destination can
* be the same object).
* @see java.awt.RenderingHints#KEY_COLOR_RENDERING
* @see java.awt.RenderingHints#KEY_DITHERING
*/
public class RescaleOp implements BufferedImageOp, RasterOp {
float[] scaleFactors;
float[] offsets;
int length = 0;
RenderingHints hints;
private int srcNbits;
private int dstNbits;
/**
* Constructs a new RescaleOp with the desired scale factors
* and offsets. The length of the scaleFactor and offset arrays
* must meet the restrictions stated in the class comments above.
* The RenderingHints argument may be null.
* @param scaleFactors the specified scale factors
* @param offsets the specified offsets
* @param hints the specified {@code RenderingHints}, or
* {@code null}
*/
public RescaleOp (float[] scaleFactors, float[] offsets,
RenderingHints hints) {
length = scaleFactors.length;
if (length > offsets.length) length = offsets.length;
this.scaleFactors = new float[length];
this.offsets = new float[length];
for (int i=0; i < length; i++) {
this.scaleFactors[i] = scaleFactors[i];
this.offsets[i] = offsets[i];
}
this.hints = hints;
}
/**
* Constructs a new RescaleOp with the desired scale factor
* and offset. The scaleFactor and offset will be applied to
* all bands in a source Raster and to all color (but not alpha)
* components in a BufferedImage.
* The RenderingHints argument may be null.
* @param scaleFactor the specified scale factor
* @param offset the specified offset
* @param hints the specified {@code RenderingHints}, or
* {@code null}
*/
public RescaleOp (float scaleFactor, float offset, RenderingHints hints) {
length = 1;
this.scaleFactors = new float[1];
this.offsets = new float[1];
this.scaleFactors[0] = scaleFactor;
this.offsets[0] = offset;
this.hints = hints;
}
/**
* Returns the scale factors in the given array. The array is also
* returned for convenience. If scaleFactors is null, a new array
* will be allocated.
* @param scaleFactors the array to contain the scale factors of
* this {@code RescaleOp}
* @return the scale factors of this {@code RescaleOp}.
*/
public final float[] getScaleFactors (float[] scaleFactors) {
if (scaleFactors == null) {
return this.scaleFactors.clone();
}
System.arraycopy (this.scaleFactors, 0, scaleFactors, 0,
Math.min(this.scaleFactors.length,
scaleFactors.length));
return scaleFactors;
}
/**
* Returns the offsets in the given array. The array is also returned
* for convenience. If offsets is null, a new array
* will be allocated.
* @param offsets the array to contain the offsets of
* this {@code RescaleOp}
* @return the offsets of this {@code RescaleOp}.
*/
public final float[] getOffsets(float[] offsets) {
if (offsets == null) {
return this.offsets.clone();
}
System.arraycopy (this.offsets, 0, offsets, 0,
Math.min(this.offsets.length, offsets.length));
return offsets;
}
/**
* Returns the number of scaling factors and offsets used in this
* RescaleOp.
* @return the number of scaling factors and offsets of this
* {@code RescaleOp}.
*/
public final int getNumFactors() {
return length;
}
/**
* Creates a ByteLookupTable to implement the rescale.
* The table may have either a SHORT or BYTE input.
* @param nElems Number of elements the table is to have.
* This will generally be 256 for byte and
* 65536 for short.
*/
private ByteLookupTable createByteLut(float[] scale,
float[] off,
int nBands,
int nElems) {
byte[][] lutData = new byte[nBands][nElems];
int band;
for (band=0; band 16) {
return false;
}
for (int i=1; i numSrcColorComp && srcCM.hasAlpha()) {
scaleConst = numSrcColorComp+1;
}
int width = src.getWidth();
int height = src.getHeight();
BufferedImage origDst = dst;
if (dst == null) {
dst = createCompatibleDestImage(src, null);
dstCM = srcCM;
}
else {
if (width != dst.getWidth()) {
throw new
IllegalArgumentException("Src width ("+width+
") not equal to dst width ("+
dst.getWidth()+")");
}
if (height != dst.getHeight()) {
throw new
IllegalArgumentException("Src height ("+height+
") not equal to dst height ("+
dst.getHeight()+")");
}
dstCM = dst.getColorModel();
if(srcCM.getColorSpace().getType() !=
dstCM.getColorSpace().getType()) {
needToConvert = true;
dst = createCompatibleDestImage(src, null);
}
}
//
// Try to use a native BI rescale operation first
//
if (ImagingLib.filter(this, src, dst) == null) {
if (src.getRaster().getNumBands() !=
dst.getRaster().getNumBands()) {
needToDraw = true;
dst = createCompatibleDestImage(src, null);
}
//
// Native BI rescale failed - convert to rasters
//
WritableRaster srcRaster = src.getRaster();
WritableRaster dstRaster = dst.getRaster();
//
// Call the raster filter method
//
filterRasterImpl(srcRaster, dstRaster, scaleConst, false);
}
if (needToDraw) {
Graphics2D g = origDst.createGraphics();
g.setComposite(AlphaComposite.Src);
g.drawImage(dst, 0, 0, width, height, null);
g.dispose();
}
if (needToConvert) {
// ColorModels are not the same
ColorConvertOp ccop = new ColorConvertOp(hints);
dst = ccop.filter(dst, origDst);
}
return dst;
}
/**
* Rescales the pixel data in the source Raster.
* If the destination Raster is null, a new Raster will be created.
* The source and destination must have the same number of bands.
* Otherwise, an IllegalArgumentException is thrown.
* Note that the number of scaling factors/offsets in this object must
* meet the restrictions stated in the class comments above.
* Otherwise, an IllegalArgumentException is thrown.
* @param src the {@code Raster} to be filtered
* @param dst the destination for the filtering operation
* or {@code null}
* @return the filtered {@code WritableRaster}.
* @throws IllegalArgumentException if {@code src} and
* {@code dst} do not have the same number of bands,
* or if the number of scaling factors and offsets in this
* {@code RescaleOp} do not meet the requirements
* stated in the class comments, or if the source and
* destination rasters differ in size.
*/
public final WritableRaster filter (Raster src, WritableRaster dst) {
return filterRasterImpl(src, dst, length, true);
}
private WritableRaster filterRasterImpl(Raster src, WritableRaster dst,
int scaleConst, boolean sCheck) {
int numBands = src.getNumBands();
int width = src.getWidth();
int height = src.getHeight();
int[] srcPix = null;
int step = 0;
int tidx = 0;
// Create a new destination Raster, if needed
if (dst == null) {
dst = createCompatibleDestRaster(src);
}
else if (height != dst.getHeight() || width != dst.getWidth()) {
throw new
IllegalArgumentException("Width or height of Rasters do not "+
"match");
}
else if (numBands != dst.getNumBands()) {
// Make sure that the number of bands are equal
throw new IllegalArgumentException("Number of bands in src "
+ numBands
+ " does not equal number of bands in dest "
+ dst.getNumBands());
}
// Make sure that the arrays match
// Make sure that the low/high/constant arrays match
if (sCheck && scaleConst != 1 && scaleConst != src.getNumBands()) {
throw new IllegalArgumentException("Number of scaling constants "+
"does not equal the number of"+
" of bands in the src raster");
}
//
// Try for a native raster rescale first
//
if (ImagingLib.filter(this, src, dst) != null) {
return dst;
}
//
// Native raster rescale failed.
// Try to see if a lookup operation can be used
//
if (canUseLookup(src, dst)) {
int srcNgray = (1 << srcNbits);
int dstNgray = (1 << dstNbits);
if (dstNgray == 256) {
ByteLookupTable lut = createByteLut(scaleFactors, offsets,
numBands, srcNgray);
LookupOp op = new LookupOp(lut, hints);
op.filter(src, dst);
} else {
ShortLookupTable lut = createShortLut(scaleFactors, offsets,
numBands, srcNgray);
LookupOp op = new LookupOp(lut, hints);
op.filter(src, dst);
}
} else {
//
// Fall back to the slow code
//
if (scaleConst > 1) {
step = 1;
}
int sminX = src.getMinX();
int sY = src.getMinY();
int dminX = dst.getMinX();
int dY = dst.getMinY();
int sX;
int dX;
//
// Determine bits per band to determine maxval for clamps.
// The min is assumed to be zero.
// REMIND: This must change if we ever support signed data types.
//
int nbits;
int[] dstMax = new int[numBands];
int[] dstMask = new int[numBands];
SampleModel dstSM = dst.getSampleModel();
for (int z=0; z