    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.png.chunks;
    018
    019import static org.apache.commons.imaging.common.BinaryFunctions.read4Bytes;
    020
    021import java.io.ByteArrayInputStream;
    022import java.io.IOException;
    023
    024public final class PngChunkGama extends PngChunk {
    025
    026    private final int gamma;
    027
    028    public PngChunkGama(final int length, final int chunkType, final int crc, final byte[] bytes) throws IOException {
    029        super(length, chunkType, crc, bytes);
    030
    031        final ByteArrayInputStream is = new ByteArrayInputStream(bytes);
    032        gamma = read4Bytes("Gamma", is, "Not a Valid PNG File: gAMA Corrupt", getByteOrder());
    033    }
    034
    035    public double getGamma() {
    036        return 1.0 / (gamma / 100000.0);
    037    }
    038
    039}