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}