1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
/*
* $Id: PNGReader.java,v 1.8 2003/03/06 21:25:45 jeremias Exp $
* ============================================================================
* The Apache Software License, Version 1.1
* ============================================================================
*
* Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modifica-
* tion, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The end-user documentation included with the redistribution, if any, must
* include the following acknowledgment: "This product includes software
* developed by the Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself, if
* and wherever such third-party acknowledgments normally appear.
*
* 4. The names "FOP" and "Apache Software Foundation" must not be used to
* endorse or promote products derived from this software without prior
* written permission. For written permission, please contact
* apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache", nor may
* "Apache" appear in their name, without prior written permission of the
* Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
* DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* ============================================================================
*
* This software consists of voluntary contributions made by many individuals
* on behalf of the Apache Software Foundation and was originally created by
* James Tauber <jtauber@jtauber.com>. For more information on the Apache
* Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.fop.image.analyser;
// Java
import java.io.InputStream;
import java.io.IOException;
// FOP
import org.apache.fop.image.FopImage;
import org.apache.fop.apps.FOUserAgent;
/**
* ImageReader object for PNG image type.
*
* @author Pankaj Narula
* @version $Id: PNGReader.java,v 1.8 2003/03/06 21:25:45 jeremias Exp $
*/
public class PNGReader implements ImageReader {
private static final int PNG_SIG_LENGTH = 24;
/** @see org.apache.fop.image.analyser.ImageReader */
public FopImage.ImageInfo verifySignature(String uri, InputStream bis,
FOUserAgent ua) throws IOException {
byte[] header = getDefaultHeader(bis);
boolean supported = ((header[0] == (byte) 0x89)
&& (header[1] == (byte) 0x50)
&& (header[2] == (byte) 0x4e)
&& (header[3] == (byte) 0x47)
&& (header[4] == (byte) 0x0d)
&& (header[5] == (byte) 0x0a)
&& (header[6] == (byte) 0x1a)
&& (header[7] == (byte) 0x0a));
if (supported) {
FopImage.ImageInfo info = getDimension(header);
info.mimeType = getMimeType();
info.inputStream = bis;
return info;
} else {
return null;
}
}
/**
* Returns the MIME type supported by this implementation.
*
* @return The MIME type
*/
public String getMimeType() {
return "image/png";
}
private FopImage.ImageInfo getDimension(byte[] header) {
FopImage.ImageInfo info = new FopImage.ImageInfo();
// png is always big endian
int byte1 = header[16] & 0xff;
int byte2 = header[17] & 0xff;
int byte3 = header[18] & 0xff;
int byte4 = header[19] & 0xff;
long l = (long) ((byte1 << 24)
| (byte2 << 16)
| (byte3 << 8)
| (byte4));
info.width = (int) l;
byte1 = header[20] & 0xff;
byte2 = header[21] & 0xff;
byte3 = header[22] & 0xff;
byte4 = header[23] & 0xff;
l = (long) ((byte1 << 24) | (byte2 << 16) | (byte3 << 8) | byte4);
info.height = (int) l;
return info;
}
private byte[] getDefaultHeader(InputStream imageStream)
throws IOException {
byte[] header = new byte[PNG_SIG_LENGTH];
try {
imageStream.mark(PNG_SIG_LENGTH + 1);
imageStream.read(header);
imageStream.reset();
} catch (IOException ex) {
try {
imageStream.reset();
} catch (IOException exbis) {
// throw the original exception, not this one
}
throw ex;
}
return header;
}
}
|
