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- /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
- /* $Id$ */
-
- package org.apache.fop.render.ps;
-
- import java.awt.image.ColorModel;
- import java.awt.image.IndexColorModel;
- import java.io.ByteArrayInputStream;
- import java.io.ByteArrayOutputStream;
- import java.io.DataInputStream;
- import java.io.IOException;
- import java.io.InputStream;
- import java.io.OutputStream;
- import java.util.zip.Deflater;
- import java.util.zip.DeflaterOutputStream;
- import java.util.zip.Inflater;
- import java.util.zip.InflaterInputStream;
-
- import org.apache.commons.io.IOUtils;
-
- import org.apache.xmlgraphics.image.loader.impl.ImageRawPNG;
- import org.apache.xmlgraphics.image.loader.impl.ImageRawStream;
- import org.apache.xmlgraphics.ps.ImageEncoder;
-
- /**
- * ImageEncoder implementation for PNG images.
- */
- public class ImageEncoderPNG implements ImageEncoder {
- private final ImageRawPNG image;
- private int numberOfInterleavedComponents;
-
- /**
- * Main constructor
- * @param image the PNG image
- */
- public ImageEncoderPNG(ImageRawPNG image) {
- this.image = image;
- ColorModel cm = ((ImageRawPNG) this.image).getColorModel();
- if (cm instanceof IndexColorModel) {
- numberOfInterleavedComponents = 1;
- } else {
- // this can be 1 (gray), 2 (gray + alpha), 3 (rgb) or 4 (rgb + alpha)
- // numberOfInterleavedComponents = (cm.hasAlpha() ? 1 : 0) + cm.getNumColorComponents();
- numberOfInterleavedComponents = cm.getNumComponents();
- }
- }
-
- /** {@inheritDoc} */
- public void writeTo(OutputStream out) throws IOException {
- // TODO: refactor this code with equivalent PDF code
- InputStream in = ((ImageRawStream) image).createInputStream();
- try {
- if (numberOfInterleavedComponents == 1 || numberOfInterleavedComponents == 3) {
- // means we have Gray, RGB, or Palette
- IOUtils.copy(in, out);
- } else {
- // means we have Gray + alpha or RGB + alpha
- int numBytes = numberOfInterleavedComponents - 1; // 1 for Gray, 3 for RGB
- int numColumns = image.getSize().getWidthPx();
- InflaterInputStream infStream = new InflaterInputStream(in, new Inflater());
- DataInputStream dataStream = new DataInputStream(infStream);
- int offset = 0;
- int bytesPerRow = numberOfInterleavedComponents * numColumns;
- int filter;
- // here we need to inflate the PNG pixel data, which includes alpha, separate the alpha
- // channel and then deflate the RGB channels back again
- // TODO: not using the baos below and using the original out instead (as happens in PDF)
- // would be preferable but that does not work with the rest of the postscript code; this
- // needs to be revisited
- ByteArrayOutputStream baos = new ByteArrayOutputStream();
- DeflaterOutputStream dos = new DeflaterOutputStream(/* out */baos, new Deflater());
- while ((filter = dataStream.read()) != -1) {
- byte[] bytes = new byte[bytesPerRow];
- dataStream.readFully(bytes, 0, bytesPerRow);
- dos.write((byte) filter);
- for (int j = 0; j < numColumns; j++) {
- dos.write(bytes, offset, numBytes);
- offset += numberOfInterleavedComponents;
- }
- offset = 0;
- }
- dos.close();
- IOUtils.copy(new ByteArrayInputStream(baos.toByteArray()), out);
- }
- } finally {
- IOUtils.closeQuietly(in);
- }
- }
-
- /** {@inheritDoc} */
- public String getImplicitFilter() {
- String filter = "<< /Predictor 15 /Columns " + image.getSize().getWidthPx();
- filter += " /Colors " + (numberOfInterleavedComponents > 2 ? 3 : 1);
- filter += " /BitsPerComponent " + image.getBitDepth() + " >> /FlateDecode";
- return filter;
- }
- }
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