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/*
* 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 javax.imageio.plugins.jpeg;
import javax.imageio.ImageReadParam;
/**
* The JPEGImageReadParam class provides functionality to set Huffman tables and
* quantization tables when using the JPEG reader plug-in.
*
* @since Android 1.0
*/
public class JPEGImageReadParam extends ImageReadParam {
/**
* The q tables.
*/
private JPEGQTable qTables[];
/**
* The dc huffman tables.
*/
private JPEGHuffmanTable dcHuffmanTables[];
/**
* The ac huffman tables.
*/
private JPEGHuffmanTable acHuffmanTables[];
/**
* Instantiates a new JPEGImageReadParam.
*/
public JPEGImageReadParam() {
}
/**
* Returns true if tables are set, false otherwise.
*
* @return true, if tables are set, false otherwise.
*/
public boolean areTablesSet() {
return qTables != null;
}
/**
* Sets the quantization and Huffman tables for using in decoding streams.
*
* @param qTables
* the quantization tables.
* @param DCHuffmanTables
* the standart DC Huffman tables.
* @param ACHuffmanTables
* the standart AC huffman tables.
*/
public void setDecodeTables(JPEGQTable[] qTables, JPEGHuffmanTable[] DCHuffmanTables,
JPEGHuffmanTable[] ACHuffmanTables) {
if (qTables == null || DCHuffmanTables == null || ACHuffmanTables == null) {
throw new IllegalArgumentException("Invalid JPEG table arrays");
}
if (DCHuffmanTables.length != ACHuffmanTables.length) {
throw new IllegalArgumentException("Invalid JPEG table arrays");
}
if (qTables.length > 4 || DCHuffmanTables.length > 4) {
throw new IllegalArgumentException("Invalid JPEG table arrays");
}
// Do the shallow copy, it should be enough
this.qTables = qTables.clone();
dcHuffmanTables = DCHuffmanTables.clone();
acHuffmanTables = ACHuffmanTables.clone();
}
/**
* Unset all decoded tables.
*/
public void unsetDecodeTables() {
qTables = null;
dcHuffmanTables = null;
acHuffmanTables = null;
}
/**
* Gets the quantization tables.
*
* @return the quantization tables, or null.
*/
public JPEGQTable[] getQTables() {
return qTables == null ? null : qTables.clone();
}
/**
* Gets the DC Huffman tables.
*
* @return the DC Huffman tables which are set, or null.
*/
public JPEGHuffmanTable[] getDCHuffmanTables() {
return dcHuffmanTables == null ? null : dcHuffmanTables.clone();
}
/**
* Gets the AC Huffman tables.
*
* @return the AC Huffman tables which are set, or null.
*/
public JPEGHuffmanTable[] getACHuffmanTables() {
return acHuffmanTables == null ? null : acHuffmanTables.clone();
}
}
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