FastCMYKToRGB.java
/*
* Copyright (c) 2011, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.twelvemonkeys.imageio.plugins.jpeg;
import com.twelvemonkeys.lang.Validate;
import java.awt.*;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.*;
/**
* This class performs a pixel by pixel conversion of the source image, from CMYK to RGB.
* <p>
* The conversion is fast, but performed without any color space conversion.
*</p>
*
* @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
* @author last modified by $Author: haraldk$
* @version $Id: FastCMYKToRGB.java,v 1.0 21.02.11 13.22 haraldk Exp$
* @see ColorConvertOp
*/
class FastCMYKToRGB implements /*BufferedImageOp,*/ RasterOp {
// TODO: Force dest alpha to match source alpha?
public FastCMYKToRGB() {
}
/**
* Converts the CMYK source raster to the destination RGB raster.
*
* @param src assumed to be 4 byte CMYK
* @param dest raster, in either 3 byte BGR/BGR, 4 byte ABGR or int RGB/ARGB format, or {@code null}
* @return {@code dest}, or a new {@link WritableRaster} if {@code dest} is {@code null}.
* @throws IllegalArgumentException if {@code src} and {@code dest} refer to the same object
*/
@Override
public WritableRaster filter(Raster src, WritableRaster dest) {
Validate.notNull(src, "src may not be null");
// TODO: Why not allow same raster, if converting to 4 byte ABGR?
Validate.isTrue(src != dest, "src and dest raster may not be same");
Validate.isTrue(src.getTransferType() == DataBuffer.TYPE_BYTE, src, "only TYPE_BYTE rasters supported as src: %s");
Validate.isTrue(src.getNumDataElements() >= 4, src.getNumDataElements(), "CMYK raster must have at least 4 data elements: %s");
if (dest == null) {
dest = createCompatibleDestRaster(src);
}
else {
Validate.isTrue(
dest.getTransferType() == DataBuffer.TYPE_BYTE && dest.getNumDataElements() >= 3 ||
dest.getTransferType() == DataBuffer.TYPE_INT && dest.getNumDataElements() == 1,
src,
"only 3 or 4 byte TYPE_BYTE or 1 int TYPE_INT rasters supported as dest: %s"
);
}
final int height = src.getHeight();
final int width = src.getWidth();
final byte[] in = new byte[src.getNumDataElements()]; // CMYK
if (dest.getTransferType() == DataBuffer.TYPE_BYTE) {
final byte[] out = new byte[dest.getNumDataElements()];
if (out.length > 3) {
out[3] = (byte) 0xFF;
}
for (int y = dest.getMinY(); y < height; y++) {
for (int x = dest.getMinX(); x < width; x++) {
src.getDataElements(x, y, in);
convertCMYKToRGB(in, out);
dest.setDataElements(x, y, out);
}
}
}
else if (dest.getTransferType() == DataBuffer.TYPE_INT) {
final int[] out = new int[dest.getNumDataElements()];
final byte[] temp = new byte[3]; // RGB
// Special case for INT_BGR types, as bit offsets are not handled in setDataElements like for the byte raster case
int[] bitOffsets;
SampleModel sm = dest.getSampleModel();
if (sm instanceof SinglePixelPackedSampleModel) {
bitOffsets = ((SinglePixelPackedSampleModel) sm).getBitOffsets();
}
else {
bitOffsets = new int[]{0, 8, 16};
}
final int alpha = bitOffsets.length > 3 ? 0xFF : 0x00;
for (int y = dest.getMinY(); y < height; y++) {
for (int x = dest.getMinX(); x < width; x++) {
src.getDataElements(x, y, in);
convertCMYKToRGB(in, temp);
out[0] = alpha << 24 | (temp[0] & 0xFF) << bitOffsets[0] | (temp[1] & 0xFF) << bitOffsets[1] | (temp[2] & 0xFF) << bitOffsets[2];
dest.setDataElements(x, y, out);
}
}
}
else {
// This is already tested for
throw new AssertionError();
}
return dest;
}
private void convertCMYKToRGB(byte[] cmyk, byte[] rgb) {
// Adapted from http://www.easyrgb.com/index.php?X=MATH
final int k = cmyk[3] & 0xFF;
rgb[0] = (byte) (255 - (((cmyk[0] & 0xFF) * (255 - k) / 255) + k));
rgb[1] = (byte) (255 - (((cmyk[1] & 0xFF) * (255 - k) / 255) + k));
rgb[2] = (byte) (255 - (((cmyk[2] & 0xFF) * (255 - k) / 255) + k));
}
@Override
public Rectangle2D getBounds2D(Raster src) {
return src.getBounds();
}
@Override
public WritableRaster createCompatibleDestRaster(final Raster src) {
// WHAT?? This code no longer work for JRE 7u45+... JRE bug?!
// Raster child = src.createChild(0, 0, src.getWidth(), src.getHeight(), 0, 0, new int[] {0, 1, 2});
// return child.createCompatibleWritableRaster(); // Throws an exception complaining about the scanline stride from the verify() method
// This is a workaround for the above code that no longer works.
// It wil use 25% more memory, but it seems to work...
return src.createCompatibleWritableRaster()
.createWritableChild(0, 0, src.getWidth(), src.getHeight(), 0, 0, new int[] {0, 1, 2});
}
@Override
public Point2D getPoint2D(Point2D srcPt, Point2D dstPt) {
if (dstPt == null) {
dstPt = new Point2D.Double(srcPt.getX(), srcPt.getY());
}
else {
dstPt.setLocation(srcPt);
}
return dstPt;
}
@Override
public RenderingHints getRenderingHints() {
return null;
}
}