JpegEncoder


1   // JpegEncoder - write out an image as a JPEG
2   //
3   // Copyright (C) 1996 by Jef Poskanzer <jef@acme.com>.  All rights reserved.
4   //
5   // Redistribution and use in source and binary forms, with or without
6   // modification, are permitted provided that the following conditions
7   // are met:
8   // 1. Redistributions of source code must retain the above copyright
9   //    notice, this list of conditions and the following disclaimer.
10  // 2. Redistributions in binary form must reproduce the above copyright
11  //    notice, this list of conditions and the following disclaimer in the
12  //    documentation and/or other materials provided with the distribution.
13  //
14  // THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  // ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  // OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  // SUCH DAMAGE.
25  //
26  // Visit the ACME Labs Java page for up-to-date versions of this and other
27  // fine Java utilities: http://www.acme.com/java/
28  
29  package Acme.JPM.Encoders;
30  
31  import java.awt.*;
32  import java.awt.image.ImageProducer  ;
33  import java.io.IOException  ;
34  import java.io.OutputStream  ;
35  
36  /// Write out an image as a JPEG.
37  // DOESN'T WORK YET.
38  // <P>
39  // <A HREF="../../../../resources/classes/Acme/JPM/Encoders/JpegEncoder.java">Fetch the software.</A><BR>
40  // <A HREF="../../../../resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>
41  // <P>
42  // @see ToJpeg
43  
44  public class JpegEncoder extends ImageEncoder {
45  
46      /// Constructor.
47      // @param img The image to encode.
48      // @param out The stream to write the JPEG to.
49      public JpegEncoder(Image img, OutputStream   out) throws IOException   {
50          super(img, out);
51      }
52  
53      /// Constructor.
54      // @param prod The ImageProducer to encode.
55      // @param out The stream to write the JPEG to.
56      public JpegEncoder(ImageProducer   prod, OutputStream   out) throws IOException   {
57          super(prod, out);
58      }
59  
60      int qfactor = 100;
61  
62      /// Set the Q-factor.
63      public void setQfactor(int qfactor) {
64          this.qfactor = qfactor;
65      }
66  
67      int width, height;
68      int[][] rgbPixels;
69  
70      void encodeStart(int width, int height) throws IOException   {
71          this.width = width;
72          this.height = height;
73          rgbPixels = new int[height][width];
74      }
75  
76      void encodePixels(int x, int y, int w, int h, int[] rgbPixels, int off, int scansize)
77              throws IOException   {
78          // Save the pixels.
79          for (int row = 0; row < h; ++row)
80              System.arraycopy(rgbPixels, row * scansize + off,
81                      this.rgbPixels[y + row], x, w);
82  
83      }
84  
85      void encodeDone() throws IOException   {
86          writeJfifHuffHeader();
87          // !!!
88      }
89      
90  
91      // Some of the following code is derived from the Berkeley Continuous
92      // Media Toolkit (http://bmrc.berkeley.edu/projects/cmt/), which is
93      // Copyright (c) 1996 The Regents of the University of California.
94      // All rights reserved.
95      //
96      // IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
97      // DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
98      // OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE
99      // UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
100     // DAMAGE.
101     //
102     // THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
103     // INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
104     // AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
105     // ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION
106     // TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
107 
108 
109     // This array represents the default JFIF header for quality = 100 and
110     // size = 640x480, with Huffman tables. The values are adjusted when a
111     // file is generated.
112     private static byte[] jfifHuff100Header = {
113         // SOI
114         (byte) 0xFF, (byte) 0xD8,
115 
116         // JFIF header
117         (byte) 0xFF, (byte) 0xE0, // Marker
118         (byte) 0x00, (byte) 0x10, // Length = 16 bytes
119         (byte) 0x4A, (byte) 0x46, (byte) 0x49, (byte) 0x46, // "JFIF"
120         (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00,
121         (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00,
122 
123         // Start of frame (section B.2.2)
124         (byte) 0xFF, (byte) 0xC0, // Baseline DCT
125         (byte) 0x00, (byte) 0x11, // Length = 17 bytes
126         (byte) 0x08, // Sample precision
127         (byte) 0x01, (byte) 0xE0, // Height
128         (byte) 0x02, (byte) 0x80, // Width
129         (byte) 0x03, // Number of components = 3
130         // Scan 1: 2:1 horiz, (byte) 1:1 vertical, (byte) use QT 0
131         (byte) 0x01, (byte) 0x21, (byte) 0x00,
132         // Scan 2: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1
133         (byte) 0x02, (byte) 0x11, (byte) 0x01,
134         // Scan 3: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1
135         (byte) 0x03, (byte) 0x11, (byte) 0x01,
136 
137         // Define Quant table (section B.2.4.1)
138         (byte) 0xFF, (byte) 0xDB, // Marker
139         (byte) 0x00, (byte) 0x84, // Length (both tables)
140         (byte) 0x00, // 8 bit values, (byte) table 0
141         (byte) 0x10, (byte) 0x0B, (byte) 0x0C, (byte) 0x0E, (byte) 0x0C,
142         (byte) 0x0A, (byte) 0x10, (byte) 0x0E, (byte) 0x0D, (byte) 0x0E,
143         (byte) 0x12, (byte) 0x11, (byte) 0x10, (byte) 0x13, (byte) 0x18,
144         (byte) 0x28, (byte) 0x1A, (byte) 0x18, (byte) 0x16, (byte) 0x16,
145         (byte) 0x18, (byte) 0x31, (byte) 0x23, (byte) 0x25, (byte) 0x1D,
146         (byte) 0x28, (byte) 0x3A, (byte) 0x33, (byte) 0x3D, (byte) 0x3C,
147         (byte) 0x39, (byte) 0x33, (byte) 0x38, (byte) 0x37, (byte) 0x40,
148         (byte) 0x48, (byte) 0x5C, (byte) 0x4E, (byte) 0x40, (byte) 0x44,
149         (byte) 0x57, (byte) 0x45, (byte) 0x37, (byte) 0x38, (byte) 0x50,
150         (byte) 0x6D, (byte) 0x51, (byte) 0x57, (byte) 0x5F, (byte) 0x62,
151         (byte) 0x67, (byte) 0x68, (byte) 0x67, (byte) 0x3E, (byte) 0x4D,
152         (byte) 0x71, (byte) 0x79, (byte) 0x70, (byte) 0x64, (byte) 0x78,
153         (byte) 0x5C, (byte) 0x65, (byte) 0x67, (byte) 0x63,
154 
155         (byte) 0x01, // 8 bit values, (byte) table 1
156         (byte) 0x11, (byte) 0x12, (byte) 0x12, (byte) 0x18, (byte) 0x15,
157         (byte) 0x18, (byte) 0x2F, (byte) 0x1A, (byte) 0x1A, (byte) 0x2F,
158         (byte) 0x63, (byte) 0x42, (byte) 0x38, (byte) 0x42, (byte) 0x63,
159         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
160         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
161         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
162         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
163         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
164         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
165         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
166         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
167         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
168         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
169 
170         // Define huffman table (section B.2.4.1)
171         (byte) 0xFF, (byte) 0xC4, // Marker
172         (byte) 0x00, (byte) 0x1F, // Length (31 bytes)
173         (byte) 0x00, // DC, (byte) table 0
174         (byte) 0x00, (byte) 0x01, (byte) 0x05, (byte) 0x01, (byte) 0x01,
175         (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00,
176         (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00,
177         (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03,
178         (byte) 0x04, (byte) 0x05, (byte) 0x06, (byte) 0x07, (byte) 0x08,
179         (byte) 0x09, (byte) 0x0A, (byte) 0x0B,
180 
181         // Define huffman table (section B.2.4.1)
182         (byte) 0xFF, (byte) 0xC4, // Marker
183         (byte) 0x00, (byte) 0xB5, // Length (181 bytes)
184         (byte) 0x10, // AC, (byte) table 0
185         (byte) 0x00, (byte) 0x02, (byte) 0x01, (byte) 0x03, (byte) 0x03,
186         (byte) 0x02, (byte) 0x04, (byte) 0x03, (byte) 0x05, (byte) 0x05,
187         (byte) 0x04, (byte) 0x04, (byte) 0x00, (byte) 0x00, (byte) 0x01,
188         (byte) 0x7D, (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x00,
189         (byte) 0x04, (byte) 0x11, (byte) 0x05, (byte) 0x12, (byte) 0x21,
190         (byte) 0x31, (byte) 0x41, (byte) 0x06, (byte) 0x13, (byte) 0x51,
191         (byte) 0x61, (byte) 0x07, (byte) 0x22, (byte) 0x71, (byte) 0x14,
192         (byte) 0x32, (byte) 0x81, (byte) 0x91, (byte) 0xA1, (byte) 0x08,
193         (byte) 0x23, (byte) 0x42, (byte) 0xB1, (byte) 0xC1, (byte) 0x15,
194         (byte) 0x52, (byte) 0xD1, (byte) 0xF0, (byte) 0x24, (byte) 0x33,
195         (byte) 0x62, (byte) 0x72, (byte) 0x82, (byte) 0x09, (byte) 0x0A,
196         (byte) 0x16, (byte) 0x17, (byte) 0x18, (byte) 0x19, (byte) 0x1A,
197         (byte) 0x25, (byte) 0x26, (byte) 0x27, (byte) 0x28, (byte) 0x29,
198         (byte) 0x2A, (byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x37,
199         (byte) 0x38, (byte) 0x39, (byte) 0x3A, (byte) 0x43, (byte) 0x44,
200         (byte) 0x45, (byte) 0x46, (byte) 0x47, (byte) 0x48, (byte) 0x49,
201         (byte) 0x4A, (byte) 0x53, (byte) 0x54, (byte) 0x55, (byte) 0x56,
202         (byte) 0x57, (byte) 0x58, (byte) 0x59, (byte) 0x5A, (byte) 0x63,
203         (byte) 0x64, (byte) 0x65, (byte) 0x66, (byte) 0x67, (byte) 0x68,
204         (byte) 0x69, (byte) 0x6A, (byte) 0x73, (byte) 0x74, (byte) 0x75,
205         (byte) 0x76, (byte) 0x77, (byte) 0x78, (byte) 0x79, (byte) 0x7A,
206         (byte) 0x83, (byte) 0x84, (byte) 0x85, (byte) 0x86, (byte) 0x87,
207         (byte) 0x88, (byte) 0x89, (byte) 0x8A, (byte) 0x92, (byte) 0x93,
208         (byte) 0x94, (byte) 0x95, (byte) 0x96, (byte) 0x97, (byte) 0x98,
209         (byte) 0x99, (byte) 0x9A, (byte) 0xA2, (byte) 0xA3, (byte) 0xA4,
210         (byte) 0xA5, (byte) 0xA6, (byte) 0xA7, (byte) 0xA8, (byte) 0xA9,
211         (byte) 0xAA, (byte) 0xB2, (byte) 0xB3, (byte) 0xB4, (byte) 0xB5,
212         (byte) 0xB6, (byte) 0xB7, (byte) 0xB8, (byte) 0xB9, (byte) 0xBA,
213         (byte) 0xC2, (byte) 0xC3, (byte) 0xC4, (byte) 0xC5, (byte) 0xC6,
214         (byte) 0xC7, (byte) 0xC8, (byte) 0xC9, (byte) 0xCA, (byte) 0xD2,
215         (byte) 0xD3, (byte) 0xD4, (byte) 0xD5, (byte) 0xD6, (byte) 0xD7,
216         (byte) 0xD8, (byte) 0xD9, (byte) 0xDA, (byte) 0xE1, (byte) 0xE2,
217         (byte) 0xE3, (byte) 0xE4, (byte) 0xE5, (byte) 0xE6, (byte) 0xE7,
218         (byte) 0xE8, (byte) 0xE9, (byte) 0xEA, (byte) 0xF1, (byte) 0xF2,
219         (byte) 0xF3, (byte) 0xF4, (byte) 0xF5, (byte) 0xF6, (byte) 0xF7,
220         (byte) 0xF8, (byte) 0xF9, (byte) 0xFA,
221 
222         // Define huffman table (section B.2.4.1)
223         (byte) 0xFF, (byte) 0xC4, // Marker
224         (byte) 0x00, (byte) 0x1F, // Length (31 bytes)
225         (byte) 0x01, // DC, (byte) table 1
226         (byte) 0x00, (byte) 0x03, (byte) 0x01, (byte) 0x01, (byte) 0x01,
227         (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01,
228         (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00,
229         (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03,
230         (byte) 0x04, (byte) 0x05, (byte) 0x06, (byte) 0x07, (byte) 0x08,
231         (byte) 0x09, (byte) 0x0A, (byte) 0x0B,
232 
233         // Define huffman table (section B.2.4.1)
234         (byte) 0xFF, (byte) 0xC4, // Marker
235         (byte) 0x00, (byte) 0xB5, // Length (181 bytes)
236         (byte) 0x11, // AC, (byte) table 1
237         (byte) 0x00, (byte) 0x02, (byte) 0x01, (byte) 0x02, (byte) 0x04,
238         (byte) 0x04, (byte) 0x03, (byte) 0x04, (byte) 0x07, (byte) 0x05,
239         (byte) 0x04, (byte) 0x04, (byte) 0x00, (byte) 0x01, (byte) 0x02,
240         (byte) 0x77, (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03,
241         (byte) 0x11, (byte) 0x04, (byte) 0x05, (byte) 0x21, (byte) 0x31,
242         (byte) 0x06, (byte) 0x12, (byte) 0x41, (byte) 0x51, (byte) 0x07,
243         (byte) 0x61, (byte) 0x71, (byte) 0x13, (byte) 0x22, (byte) 0x32,
244         (byte) 0x81, (byte) 0x08, (byte) 0x14, (byte) 0x42, (byte) 0x91,
245         (byte) 0xA1, (byte) 0xB1, (byte) 0xC1, (byte) 0x09, (byte) 0x23,
246         (byte) 0x33, (byte) 0x52, (byte) 0xF0, (byte) 0x15, (byte) 0x62,
247         (byte) 0x72, (byte) 0xD1, (byte) 0x0A, (byte) 0x16, (byte) 0x24,
248         (byte) 0x34, (byte) 0xE1, (byte) 0x25, (byte) 0xF1, (byte) 0x17,
249         (byte) 0x18, (byte) 0x19, (byte) 0x1A, (byte) 0x26, (byte) 0x27,
250         (byte) 0x28, (byte) 0x29, (byte) 0x2A, (byte) 0x35, (byte) 0x36,
251         (byte) 0x37, (byte) 0x38, (byte) 0x39, (byte) 0x3A, (byte) 0x43,
252         (byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47, (byte) 0x48,
253         (byte) 0x49, (byte) 0x4A, (byte) 0x53, (byte) 0x54, (byte) 0x55,
254         (byte) 0x56, (byte) 0x57, (byte) 0x58, (byte) 0x59, (byte) 0x5A,
255         (byte) 0x63, (byte) 0x64, (byte) 0x65, (byte) 0x66, (byte) 0x67,
256         (byte) 0x68, (byte) 0x69, (byte) 0x6A, (byte) 0x73, (byte) 0x74,
257         (byte) 0x75, (byte) 0x76, (byte) 0x77, (byte) 0x78, (byte) 0x79,
258         (byte) 0x7A, (byte) 0x82, (byte) 0x83, (byte) 0x84, (byte) 0x85,
259         (byte) 0x86, (byte) 0x87, (byte) 0x88, (byte) 0x89, (byte) 0x8A,
260         (byte) 0x92, (byte) 0x93, (byte) 0x94, (byte) 0x95, (byte) 0x96,
261         (byte) 0x97, (byte) 0x98, (byte) 0x99, (byte) 0x9A, (byte) 0xA2,
262         (byte) 0xA3, (byte) 0xA4, (byte) 0xA5, (byte) 0xA6, (byte) 0xA7,
263         (byte) 0xA8, (byte) 0xA9, (byte) 0xAA, (byte) 0xB2, (byte) 0xB3,
264         (byte) 0xB4, (byte) 0xB5, (byte) 0xB6, (byte) 0xB7, (byte) 0xB8,
265         (byte) 0xB9, (byte) 0xBA, (byte) 0xC2, (byte) 0xC3, (byte) 0xC4,
266         (byte) 0xC5, (byte) 0xC6, (byte) 0xC7, (byte) 0xC8, (byte) 0xC9,
267         (byte) 0xCA, (byte) 0xD2, (byte) 0xD3, (byte) 0xD4, (byte) 0xD5,
268         (byte) 0xD6, (byte) 0xD7, (byte) 0xD8, (byte) 0xD9, (byte) 0xDA,
269         (byte) 0xE2, (byte) 0xE3, (byte) 0xE4, (byte) 0xE5, (byte) 0xE6,
270         (byte) 0xE7, (byte) 0xE8, (byte) 0xE9, (byte) 0xEA, (byte) 0xF2,
271         (byte) 0xF3, (byte) 0xF4, (byte) 0xF5, (byte) 0xF6, (byte) 0xF7,
272         (byte) 0xF8, (byte) 0xF9, (byte) 0xFA,
273 
274         // Start of Scan (section B.2.3)
275         (byte) 0xFF, (byte) 0xDA, // Marker
276         (byte) 0x00, (byte) 0x0C, // Length of header
277         (byte) 0x03, // Number of image components
278         // Scan 1: use DC/AC huff tables 0/0
279         (byte) 0x01, (byte) 0x00,
280         // Scan 2: use DC/AC huff tables 1/1
281         (byte) 0x02, (byte) 0x11,
282         // Scan 3: use DC/AC huff tables 1/1
283         (byte) 0x03, (byte) 0x11,
284         (byte) 0x00, (byte) 0x3F, (byte) 0x00   // Not used
285     };
286 
287     // This array represents the default JFIF header for quality = 100 and
288     // size = 640x480, without Huffman tables. The values are adjusted when a
289     // file is generated.
290     private static byte[] jfifNoHuff100Header = {
291         // SOI
292         (byte) 0xFF, (byte) 0xD8,
293 
294         // JFIF header
295         (byte) 0xFF, (byte) 0xE0, // Marker
296         (byte) 0x00, (byte) 0x10, // Length = 16 bytes
297         (byte) 0x4A, (byte) 0x46, (byte) 0x49, (byte) 0x46, // "JFIF"
298         (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00,
299         (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00,
300 
301         // Start of frame (section B.2.2)
302         (byte) 0xFF, (byte) 0xC0, // Baseline DCT
303         (byte) 0x00, (byte) 0x11, // Length = 17 bytes
304         (byte) 0x08, // Sample precision
305         (byte) 0x01, (byte) 0xE0, // Height
306         (byte) 0x02, (byte) 0x80, // Width
307         (byte) 0x03, // Number of components = 3
308         // Scan 1: 2:1 horiz, (byte) 1:1 vertical, (byte) use QT 0
309         (byte) 0x01, (byte) 0x21, (byte) 0x00,
310         // Scan 2: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1
311         (byte) 0x02, (byte) 0x11, (byte) 0x01,
312         // Scan 3: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1
313         (byte) 0x03, (byte) 0x11, (byte) 0x01,
314 
315         // Define Quant table (section B.2.4.1)
316         (byte) 0xFF, (byte) 0xDB, // Marker
317         (byte) 0x00, (byte) 0x84, // Length (both tables)
318         (byte) 0x00, // 8 bit values, (byte) table 0
319         (byte) 0x10, (byte) 0x0B, (byte) 0x0C, (byte) 0x0E, (byte) 0x0C,
320         (byte) 0x0A, (byte) 0x10, (byte) 0x0E, (byte) 0x0D, (byte) 0x0E,
321         (byte) 0x12, (byte) 0x11, (byte) 0x10, (byte) 0x13, (byte) 0x18,
322         (byte) 0x28, (byte) 0x1A, (byte) 0x18, (byte) 0x16, (byte) 0x16,
323         (byte) 0x18, (byte) 0x31, (byte) 0x23, (byte) 0x25, (byte) 0x1D,
324         (byte) 0x28, (byte) 0x3A, (byte) 0x33, (byte) 0x3D, (byte) 0x3C,
325         (byte) 0x39, (byte) 0x33, (byte) 0x38, (byte) 0x37, (byte) 0x40,
326         (byte) 0x48, (byte) 0x5C, (byte) 0x4E, (byte) 0x40, (byte) 0x44,
327         (byte) 0x57, (byte) 0x45, (byte) 0x37, (byte) 0x38, (byte) 0x50,
328         (byte) 0x6D, (byte) 0x51, (byte) 0x57, (byte) 0x5F, (byte) 0x62,
329         (byte) 0x67, (byte) 0x68, (byte) 0x67, (byte) 0x3E, (byte) 0x4D,
330         (byte) 0x71, (byte) 0x79, (byte) 0x70, (byte) 0x64, (byte) 0x78,
331         (byte) 0x5C, (byte) 0x65, (byte) 0x67, (byte) 0x63,
332 
333         (byte) 0x01, // 8 bit values, (byte) table 1
334         (byte) 0x11, (byte) 0x12, (byte) 0x12, (byte) 0x18, (byte) 0x15,
335         (byte) 0x18, (byte) 0x2F, (byte) 0x1A, (byte) 0x1A, (byte) 0x2F,
336         (byte) 0x63, (byte) 0x42, (byte) 0x38, (byte) 0x42, (byte) 0x63,
337         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
338         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
339         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
340         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
341         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
342         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
343         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
344         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
345         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
346         (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63,
347 
348         // Start of Scan (section B.2.3)
349         (byte) 0xFF, (byte) 0xDA, // Marker
350         (byte) 0x00, (byte) 0x0C, // Length of header
351         (byte) 0x03, // Number of image components
352         // Scan 1: use DC/AC huff tables 0/0
353         (byte) 0x01, (byte) 0x00,
354         // Scan 2: use DC/AC huff tables 1/1
355         (byte) 0x02, (byte) 0x11,
356         // Scan 3: use DC/AC huff tables 1/1
357         (byte) 0x03, (byte) 0x11,
358         (byte) 0x00, (byte) 0x3F, (byte) 0x00   // Not used
359     };
360 
361     private void writeJfifHuffHeader() throws IOException   {
362         byte[] newHeader = new byte[jfifHuff100Header.length];
363 
364         System.arraycopy(jfifHuff100Header, 0, newHeader, 0, jfifHuff100Header.length);
365 
366         // Set image width in JFIF header.
367         newHeader[27] = (byte) ((width >>> 8) & 0xff);
368         newHeader[28] = (byte) (width & 0xff);
369 
370         // Set image height in JFIF header.
371         newHeader[25] = (byte) ((height >>> 8) & 0xff);
372         newHeader[26] = (byte) (height & 0xff);
373 
374         // Adjust the quality factor.
375         //
376         // The default quality factor is 100, therefore if
377         // our quality factor does not equal 100 we must
378         // scale the quantization matrices in the JFIF header.
379         // Note that values are clipped to a max of 255.
380         if (qfactor != 100) {
381             for (int i = 44; i < 108; ++i) {
382                 int t = (newHeader[i] * qfactor) / 100;
383                 newHeader[i] = (byte) Math.max(t, 0xff);
384             }
385             for (int i = 109; i < 173; ++i) {
386                 int t = (newHeader[i] * qfactor) / 100;
387                 newHeader[i] = (byte) Math.max(t, 0xff);
388             }
389         }
390 
391         // Write out buffer.
392         out.write(newHeader);
393     }
394 
395     private void writeJfifNoHuffHeader() throws IOException   {
396         byte[] newHeader = new byte[jfifNoHuff100Header.length];
397 
398         System.arraycopy(jfifNoHuff100Header, 0, newHeader, 0, jfifNoHuff100Header.length);
399 
400         // Set image width in JFIF header.
401         newHeader[27] = (byte) ((width >>> 8) & 0xff);
402         newHeader[28] = (byte) (width & 0xff);
403 
404         // Set image height in JFIF header.
405         newHeader[25] = (byte) ((height >>> 8) & 0xff);
406         newHeader[26] = (byte) (height & 0xff);
407 
408         // Adjust the quality factor.
409         //
410         // The default quality factor is 100, therefore if
411         // our quality factor does not equal 100 we must
412         // scale the quantization matrices in the JFIF header.
413         // Note that values are clipped to a max of 255.
414         if (qfactor != 100) {
415             for (int i = 44; i < 108; ++i) {
416                 int t = (newHeader[i] * qfactor) / 100;
417                 newHeader[i] = (byte) Math.max(t, 0xff);
418             }
419             for (int i = 109; i < 173; ++i) {
420                 int t = (newHeader[i] * qfactor) / 100;
421                 newHeader[i] = (byte) Math.max(t, 0xff);
422             }
423         }
424 
425         // Write out buffer.
426         out.write(newHeader);
427     }
428 
429 }
430
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