org.apache.commons.imaging.formats.png.chunks.PngChunkIhdr Maven / Gradle / Ivy
/*
* 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.
*/
package org.apache.commons.imaging.formats.png.chunks;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import org.apache.commons.imaging.ImageReadException;
import org.apache.commons.imaging.formats.png.PngColorType;
import org.apache.commons.imaging.formats.png.InterlaceMethod;
import static org.apache.commons.imaging.common.BinaryFunctions.*;
public class PngChunkIhdr extends PngChunk {
public final int width;
public final int height;
public final int bitDepth;
public final PngColorType pngColorType;
public final int compressionMethod;
public final int filterMethod;
public final InterlaceMethod interlaceMethod;
public PngChunkIhdr(int length, int chunkType, int crc, byte[] bytes) throws ImageReadException, IOException {
super(length, chunkType, crc, bytes);
final ByteArrayInputStream is = new ByteArrayInputStream(bytes);
width = read4Bytes("Width", is, "Not a Valid Png File: IHDR Corrupt", getByteOrder());
height = read4Bytes("Height", is, "Not a Valid Png File: IHDR Corrupt", getByteOrder());
bitDepth = readByte("BitDepth", is, "Not a Valid Png File: IHDR Corrupt");
int type = readByte("ColorType", is, "Not a Valid Png File: IHDR Corrupt");
pngColorType = PngColorType.getColorType(type);
if (pngColorType == null) {
throw new ImageReadException("PNG: unknown color type: " + type);
}
compressionMethod = readByte("CompressionMethod", is, "Not a Valid Png File: IHDR Corrupt");
filterMethod = readByte("FilterMethod", is, "Not a Valid Png File: IHDR Corrupt");
int method = readByte("InterlaceMethod", is, "Not a Valid Png File: IHDR Corrupt");
if (method < 0 && method >= InterlaceMethod.values().length) {
throw new ImageReadException("PNG: unknown interlace method: " + method);
}
interlaceMethod = InterlaceMethod.values()[method];
}
}