    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}