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Diffstat (limited to 'awt/javax/imageio/plugins/jpeg/JPEGHuffmanTable.java')
| -rw-r--r-- | awt/javax/imageio/plugins/jpeg/JPEGHuffmanTable.java | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/awt/javax/imageio/plugins/jpeg/JPEGHuffmanTable.java b/awt/javax/imageio/plugins/jpeg/JPEGHuffmanTable.java new file mode 100644 index 0000000..398c960 --- /dev/null +++ b/awt/javax/imageio/plugins/jpeg/JPEGHuffmanTable.java @@ -0,0 +1,213 @@ +/* + * 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; + +/** + * The JPEGHuffmanTable class represents a single JPEG Huffman table. + * It contains the standard tables from the JPEG specification. + */ +public class JPEGHuffmanTable { + + /** The standard DC luminance Huffman table . */ + public static final JPEGHuffmanTable StdDCLuminance = new JPEGHuffmanTable( + new short[] {0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0}, + new short[] {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0x0A, 0x0B}, + false + ); + + /** The standard DC chrominance Huffman table. */ + public static final JPEGHuffmanTable StdDCChrominance = new JPEGHuffmanTable( + new short[] {0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0}, + new short[] {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0x0A, 0x0B}, + false + ); + + /** The standard AC luminance Huffman table. */ + public static final JPEGHuffmanTable StdACLuminance = new JPEGHuffmanTable( + new short[] {0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7D}, + new short[] { + 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 0x21, 0x31, 0x41, 0x06, + 0x13, 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xA1, 0x08, + 0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0, 0x24, 0x33, 0x62, 0x72, + 0x82, 0x09, 0x0A, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x25, 0x26, 0x27, 0x28, + 0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x43, 0x44, 0x45, + 0x46, 0x47, 0x48, 0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, + 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x73, 0x74, 0x75, + 0x76, 0x77, 0x78, 0x79, 0x7A, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, + 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, + 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, + 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, + 0xCA, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE1, 0xE2, + 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xF1, 0xF2, 0xF3, 0xF4, + 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA + }, + false + ); + + /** + * The standard AC chrominance Huffman table. */ + public static final JPEGHuffmanTable StdACChrominance = new JPEGHuffmanTable( + new short[] {0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77}, + new short[] { + 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 0x31, 0x06, 0x12, 0x41, + 0x51, 0x07, 0x61, 0x71, 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, + 0xA1, 0xB1, 0xC1, 0x09, 0x23, 0x33, 0x52, 0xF0, 0x15, 0x62, 0x72, 0xD1, + 0x0A, 0x16, 0x24, 0x34, 0xE1, 0x25, 0xF1, 0x17, 0x18, 0x19, 0x1A, 0x26, + 0x27, 0x28, 0x29, 0x2A, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x43, 0x44, + 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, + 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x73, 0x74, + 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, + 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, + 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, + 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, + 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xF2, 0xF3, 0xF4, + 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA + }, + false + ); + + /** The lengths. */ + private short lengths[]; + + /** The values. */ + private short values[]; + + /** + * Instantiates a new jPEG huffman table. + * + * @param lengths the lengths + * @param values the values + * @param copy the copy + */ + JPEGHuffmanTable(short[] lengths, short[] values, boolean copy) { + // Construction of standard tables without checks + // The third param is dummy + // Could be also used for copying of the existing tables + this.lengths = lengths; + this.values = values; + } + + /** + * Instantiates a new JPEGHuffmanTable. + * + * @param lengths the array of shorts lengths. + * @param values the array of shorts containing + * the values in order of increasing code length. + */ + public JPEGHuffmanTable(short[] lengths, short[] values) { + if (lengths == null) { + throw new IllegalArgumentException("lengths array is null!"); + } + if (values == null) { + throw new IllegalArgumentException("values array is null!"); + } + if (lengths.length > 16) { // According to the spec + throw new IllegalArgumentException("lengths array is too long!"); + } + if (values.length > 256) { // According to the spec + throw new IllegalArgumentException("values array is too long"); + } + for (short length : lengths) { + if (length < 0) { + throw new IllegalArgumentException("Values in lengths array must be non-negative."); + } + } + for (short value : values) { + if (value < 0) { + throw new IllegalArgumentException("Values in values array must be non-negative."); + } + } + + checkHuffmanTable(lengths, values); + + this.lengths = new short[lengths.length]; + this.values = new short[values.length]; + System.arraycopy(lengths, 0, this.lengths, 0, lengths.length); + System.arraycopy(values, 0, this.values, 0, values.length); + } + + /** + * Gets an array of lengths in the Huffman table. + * + * @return the array of short values representing the + * length values in the Huffman table. + */ + public short[] getLengths() { + short newLengths[] = new short[lengths.length]; + System.arraycopy(lengths, 0, newLengths, 0, lengths.length); + return newLengths; + } + + /** + * Gets an array of values represented by increasing length of + * their codes. + * + * @return the array of values. + */ + public short[] getValues() { + short newValues[] = new short[values.length]; + System.arraycopy(values, 0, newValues, 0, values.length); + return newValues; + } + + /** + * Check huffman table. + * + * @param lengths the lengths + * @param values the values + */ + private static void checkHuffmanTable(short[] lengths, short[] values) { + int numLeaves = 0; + int possibleLeaves = 2; + for (short length : lengths) { + numLeaves += length; + possibleLeaves -= length; + if (possibleLeaves < 0) { + throw new IllegalArgumentException("Invalid Huffman table provided, lengths are incorrect."); + } + possibleLeaves <<= 1; + } + + if (values.length != numLeaves) { + throw new IllegalArgumentException("Invalid Huffman table provided, sum of lengths != values."); + } + } + + /** + * Returns the string representation of this JPEGHuffmanTable object. + * + * @return the string representation of this JPEGHuffmanTable object. + */ + @Override + public String toString() { + StringBuffer sb = new StringBuffer(); + + sb.append("JPEGHuffmanTable:\nlengths:"); + for (short length : lengths) { + sb.append(' ').append(length); + } + + sb.append("\nvalues:"); + for (short value : values) { + sb.append(' ').append(value); + } + + return sb.toString(); + } +} |