001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.imaging.formats.tiff.photometricinterpreters;
018
019import java.io.IOException;
020
021import org.apache.commons.imaging.ImageReadException;
022import org.apache.commons.imaging.common.ImageBuilder;
023
024public class PhotometricInterpreterPalette extends PhotometricInterpreter {
025
026    /**
027     * The color map of integer ARGB values tied to the pixel index of the
028     * palette
029     */
030    private final int[] indexColorMap;
031    private final int bitsPerPixelMask;
032
033    public PhotometricInterpreterPalette(final int samplesPerPixel,
034            final int[] bitsPerSample, final int predictor, final int width, final int height,
035            final int[] colorMap) {
036        super(samplesPerPixel, bitsPerSample, predictor, width, height);
037
038        final int bitsPerPixel = getBitsPerSample(0);
039        final int colormapScale = (1 << bitsPerPixel);
040        indexColorMap = new int[colormapScale];
041        for (int index = 0; index < colormapScale; index++) {
042            final int red = (colorMap[index] >> 8) & 0xff;
043            final int green = (colorMap[index + (colormapScale)] >> 8) & 0xff;
044            final int blue = (colorMap[index + (2 * colormapScale)] >> 8) & 0xff;
045            indexColorMap[index] = 0xff000000 | (red << 16) | (green << 8)
046                    | blue;
047        }
048
049        // Fix for IMAGING-247  5/17/2020
050        // This interpreter is used with TIFF_COMPRESSION_PACKBITS (32773).
051        // which unpacks to 8 bits per sample.  But if the bits-per-pixel
052        // is less than 8 bits, some authoring tools do not zero-out the
053        // unused bits.  This results in cases where the decoded by index
054        // exceeds the size of the palette.  So we set up a mask to protect
055        // the code from an array bounds exception.
056        int temp = 0;
057        for (int i = 0; i < bitsPerPixel; i++) {
058            temp = (temp << 1) | 1;
059        }
060        bitsPerPixelMask = temp;
061
062    }
063
064    @Override
065    public void interpretPixel(final ImageBuilder imageBuilder, final int[] samples, final int x,
066            final int y) throws ImageReadException, IOException {
067        imageBuilder.setRGB(x, y, indexColorMap[samples[0] & bitsPerPixelMask]);
068    }
069}