Hi,
I committed this patch to implement JPEGQTable and eliminate unnecessary
fields in JPEGHuffmanTable. I also committed a new JPEGQTable test to
Mauve.
Tom
2006-03-30 Thomas Fitzsimmons <[EMAIL PROTECTED]>
* javax/imageio/plugins/jpeg/JPEGQTable.java: New file.
* javax/imageio/plugins/jpeg/JPEGHuffmanTable.java
(ACChrominanceLengths, ACChrominanceValues, ACLuminanceLengths,
ACLuminanceValues, DCChrominanceLengths, DCChrominanceValues,
DCLuminanceLengths, DCLuminanceValues): Remove fields.
Index: javax/imageio/plugins/jpeg/JPEGHuffmanTable.java
===================================================================
RCS file: /sources/classpath/classpath/javax/imageio/plugins/jpeg/JPEGHuffmanTable.java,v
retrieving revision 1.1
diff -u -r1.1 JPEGHuffmanTable.java
--- javax/imageio/plugins/jpeg/JPEGHuffmanTable.java 10 Mar 2006 06:13:14 -0000 1.1
+++ javax/imageio/plugins/jpeg/JPEGHuffmanTable.java 31 Mar 2006 01:59:44 -0000
@@ -45,119 +45,113 @@
*/
public class JPEGHuffmanTable
{
+ /**
+ * Huffman code lengths.
+ */
private short[] lengths;
+ /**
+ * Huffman values.
+ */
private short[] values;
- private static short[] ACChrominanceLengths = { 0, 2, 1, 2, 4, 4, 3, 4, 7, 5,
- 4, 4, 0, 1, 2, 0x77 };
-
- private static short[] ACChrominanceValues = { 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 };
-
- private static short[] ACLuminanceLengths = { 0, 2, 1, 3, 3, 2, 4, 3, 5, 5,
- 4, 4, 0, 0, 1, 0x7d };
-
- private static short[] ACLuminanceValues = { 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 };
-
- private static short[] DCChrominanceLengths = { 0, 3, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, 0, 0, 0, 0, 0 };
-
- private static short[] DCChrominanceValues = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 10, 11 };
-
- private static short[] DCLuminanceLengths = { 0, 1, 5, 1, 1, 1, 1, 1, 1, 0,
- 0, 0, 0, 0, 0, 0 };
-
- private static short[] DCLuminanceValues = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
- 10, 11 };
-
/**
* The standard JPEG AC chrominance Huffman table.
*/
public static final JPEGHuffmanTable StdACChrominance =
- new JPEGHuffmanTable(ACChrominanceLengths, ACChrominanceValues);
+ 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 });
/**
* The standard JPEG AC luminance Huffman table.
*/
public static final JPEGHuffmanTable StdACLuminance =
- new JPEGHuffmanTable(ACLuminanceLengths, ACLuminanceValues);
+ 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 });
/**
* The standard JPEG DC chrominance Huffman table.
*/
public static final JPEGHuffmanTable StdDCChrominance =
- new JPEGHuffmanTable(DCChrominanceLengths, DCChrominanceValues);
+ 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,
+ 10, 11 });
/**
* The standard JPEG DC luminance Huffman table.
*/
public static final JPEGHuffmanTable StdDCLuminance =
- new JPEGHuffmanTable(DCLuminanceLengths, DCLuminanceValues);
+ 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,
+ 10, 11 });
/**
* Construct and initialize a Huffman table. Copies are created of
Index: javax/imageio/plugins/jpeg/JPEGQTable.java
===================================================================
RCS file: javax/imageio/plugins/jpeg/JPEGQTable.java
diff -N javax/imageio/plugins/jpeg/JPEGQTable.java
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ javax/imageio/plugins/jpeg/JPEGQTable.java 31 Mar 2006 01:59:44 -0000
@@ -0,0 +1,179 @@
+/* JPEGQTable.java --
+ Copyright (C) 2006 Free Software Foundation, Inc.
+
+ This file is part of GNU Classpath.
+
+ GNU Classpath is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ GNU Classpath is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GNU Classpath; see the file COPYING. If not, write to the
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ 02110-1301 USA.
+
+ Linking this library statically or dynamically with other modules is
+ making a combined work based on this library. Thus, the terms and
+ conditions of the GNU General Public License cover the whole
+ combination.
+
+ As a special exception, the copyright holders of this library give you
+ permission to link this library with independent modules to produce an
+ executable, regardless of the license terms of these independent
+ modules, and to copy and distribute the resulting executable under
+ terms of your choice, provided that you also meet, for each linked
+ independent module, the terms and conditions of the license of that
+ module. An independent module is a module which is not derived from
+ or based on this library. If you modify this library, you may extend
+ this exception to your version of the library, but you are not
+ obligated to do so. If you do not wish to do so, delete this
+ exception statement from your version. */
+
+
+package javax.imageio.plugins.jpeg;
+
+/**
+ * The JPEGQTable class represents a quantization table that can be
+ * used to encode or decode a JPEG stream. The standard JPEG
+ * luminance and chrominance quantization tables are provided as
+ * static fields. Table entries are stored in natural order, not
+ * zig-zag order.
+ */
+public class JPEGQTable
+{
+ /**
+ * The table entries, stored in natural order.
+ */
+ private int[] table;
+
+ /**
+ * The standard JPEG luminance quantization table. Values are
+ * stored in natural order.
+ */
+ public static final JPEGQTable K1Luminance = new JPEGQTable(new int[]
+ {
+ 16, 11, 10, 16, 24, 40, 51, 61,
+ 12, 12, 14, 19, 26, 58, 60, 55,
+ 14, 13, 16, 24, 40, 57, 69, 56,
+ 14, 17, 22, 29, 51, 87, 80, 62,
+ 18, 22, 37, 56, 68, 109, 103, 77,
+ 24, 35, 55, 64, 81, 104, 113, 92,
+ 49, 64, 78, 87, 103, 121, 120, 101,
+ 72, 92, 95, 98, 112, 100, 103, 99
+ });
+
+ /**
+ * The standard JPEG luminance quantization table, scaled by
+ * one-half. Values are stored in natural order.
+ */
+ public static final JPEGQTable K1Div2Luminance =
+ K1Luminance.getScaledInstance(0.5f, true);
+
+ /**
+ * The standard JPEG chrominance quantization table. Values are
+ * stored in natural order.
+ */
+ public static final JPEGQTable K2Chrominance = new JPEGQTable(new int[]
+ {
+ 17, 18, 24, 47, 99, 99, 99, 99,
+ 18, 21, 26, 66, 99, 99, 99, 99,
+ 24, 26, 56, 99, 99, 99, 99, 99,
+ 47, 66, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99
+ });
+
+ /**
+ * The standard JPEG chrominance quantization table, scaled by
+ * one-half. Values are stored in natural order.
+ */
+ public static final JPEGQTable K2Div2Chrominance =
+ K2Chrominance.getScaledInstance(0.5f, true);
+
+ /**
+ * Construct a new JPEG quantization table.
+ *
+ * @param table the 64-element value table, stored in natural order.
+ *
+ * @throws IllegalArgumentException if the table is null or if
+ * table's length is not equal to 64.
+ */
+ public JPEGQTable(int[] table)
+ {
+ if (table == null || table.length != 64)
+ throw new IllegalArgumentException("invalid JPEG quantization table");
+
+ this.table = new int[table.length];
+ System.arraycopy(table, 0, this.table, 0, table.length);
+ }
+
+ /**
+ * Retrieve a copy of the quantization values for this table.
+ *
+ * @return a copy of the quantization value array
+ */
+ public int[] getTable()
+ {
+ int[] tableCopy = new int[table.length];
+ System.arraycopy(table, 0, tableCopy, 0, table.length);
+ return tableCopy;
+ }
+
+ /**
+ * Retrieve a copy of this JPEG quantization table with every value
+ * scaled by the given scale factor, and clamped from 1 to 255
+ * baseline or from 1 to 32767 otherwise.
+ *
+ * @param scaleFactor the factor by which to scale this table
+ * @param forceBaseline clamp scaled values to a maximum of 255 if
+ * true, 32767 if false
+ *
+ * @return a new scaled JPEG quantization table
+ */
+ public JPEGQTable getScaledInstance(float scaleFactor,
+ boolean forceBaseline)
+ {
+ int[] scaledTable = getTable();
+ int max = forceBaseline ? 255 : 32767;
+
+ for (int i = 0; i < scaledTable.length; i++)
+ {
+ scaledTable[i] = Math.round (scaleFactor * (float) scaledTable[i]);
+ if (scaledTable[i] < 1)
+ scaledTable[i] = 1;
+ else if (scaledTable[i] > max)
+ scaledTable[i] = max;
+ }
+
+ return new JPEGQTable(scaledTable);
+ }
+
+ /**
+ * Create a string representing this JPEG quantization table.
+ */
+ public String toString()
+ {
+ StringBuffer buffer = new StringBuffer();
+
+ buffer.append("JPEGQTable:\n");
+ for (int i = 0; i < 8; i++)
+ {
+ buffer.append(" ");
+ for (int j = 0; j < 8; j++)
+ {
+ buffer.append(table[i * 8 + j] + " ");
+ }
+ buffer.append("\n");
+ }
+
+ return buffer.toString();
+ }
+}
