source: josm/trunk/src/com/drew/metadata/exif/ExifIFD0Descriptor.java@ 7080

Last change on this file since 7080 was 6127, checked in by bastiK, 12 years ago

applied #8895 - Upgrade metadata-extractor to v. 2.6.4 (patch by ebourg)
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 8.0 KB
Line 
1/*
2 * Copyright 2002-2012 Drew Noakes
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 * More information about this project is available at:
17 *
18 * http://drewnoakes.com/code/exif/
19 * http://code.google.com/p/metadata-extractor/
20 */
21
22package com.drew.metadata.exif;
23
24import com.drew.lang.Rational;
25import com.drew.lang.annotations.NotNull;
26import com.drew.lang.annotations.Nullable;
27import com.drew.metadata.TagDescriptor;
28
29import java.io.UnsupportedEncodingException;
30
31/**
32 * Provides human-readable string representations of tag values stored in a <code>ExifIFD0Directory</code>.
33 *
34 * @author Drew Noakes http://drewnoakes.com
35 */
36public class ExifIFD0Descriptor extends TagDescriptor<ExifIFD0Directory>
37{
38 /**
39 * Dictates whether rational values will be represented in decimal format in instances
40 * where decimal notation is elegant (such as 1/2 -> 0.5, but not 1/3).
41 */
42 private final boolean _allowDecimalRepresentationOfRationals = true;
43
44 public ExifIFD0Descriptor(@NotNull ExifIFD0Directory directory)
45 {
46 super(directory);
47 }
48
49 // Note for the potential addition of brightness presentation in eV:
50 // Brightness of taken subject. To calculate Exposure(Ev) from BrightnessValue(Bv),
51 // you must add SensitivityValue(Sv).
52 // Ev=BV+Sv Sv=log2(ISOSpeedRating/3.125)
53 // ISO100:Sv=5, ISO200:Sv=6, ISO400:Sv=7, ISO125:Sv=5.32.
54
55 /**
56 * Returns a descriptive value of the the specified tag for this image.
57 * Where possible, known values will be substituted here in place of the raw
58 * tokens actually kept in the Exif segment. If no substitution is
59 * available, the value provided by getString(int) will be returned.
60 * @param tagType the tag to find a description for
61 * @return a description of the image's value for the specified tag, or
62 * <code>null</code> if the tag hasn't been defined.
63 */
64 @Nullable
65 public String getDescription(int tagType)
66 {
67 switch (tagType) {
68 case ExifIFD0Directory.TAG_RESOLUTION_UNIT:
69 return getResolutionDescription();
70 case ExifIFD0Directory.TAG_YCBCR_POSITIONING:
71 return getYCbCrPositioningDescription();
72 case ExifIFD0Directory.TAG_X_RESOLUTION:
73 return getXResolutionDescription();
74 case ExifIFD0Directory.TAG_Y_RESOLUTION:
75 return getYResolutionDescription();
76 case ExifIFD0Directory.TAG_REFERENCE_BLACK_WHITE:
77 return getReferenceBlackWhiteDescription();
78 case ExifIFD0Directory.TAG_ORIENTATION:
79 return getOrientationDescription();
80
81 case ExifIFD0Directory.TAG_WIN_AUTHOR:
82 return getWindowsAuthorDescription();
83 case ExifIFD0Directory.TAG_WIN_COMMENT:
84 return getWindowsCommentDescription();
85 case ExifIFD0Directory.TAG_WIN_KEYWORDS:
86 return getWindowsKeywordsDescription();
87 case ExifIFD0Directory.TAG_WIN_SUBJECT:
88 return getWindowsSubjectDescription();
89 case ExifIFD0Directory.TAG_WIN_TITLE:
90 return getWindowsTitleDescription();
91
92 default:
93 return super.getDescription(tagType);
94 }
95 }
96
97 @Nullable
98 public String getReferenceBlackWhiteDescription()
99 {
100 int[] ints = _directory.getIntArray(ExifIFD0Directory.TAG_REFERENCE_BLACK_WHITE);
101 if (ints==null)
102 return null;
103 int blackR = ints[0];
104 int whiteR = ints[1];
105 int blackG = ints[2];
106 int whiteG = ints[3];
107 int blackB = ints[4];
108 int whiteB = ints[5];
109 return "[" + blackR + "," + blackG + "," + blackB + "] " +
110 "[" + whiteR + "," + whiteG + "," + whiteB + "]";
111 }
112
113 @Nullable
114 public String getYResolutionDescription()
115 {
116 Rational value = _directory.getRational(ExifIFD0Directory.TAG_Y_RESOLUTION);
117 if (value==null)
118 return null;
119 final String unit = getResolutionDescription();
120 return value.toSimpleString(_allowDecimalRepresentationOfRationals) +
121 " dots per " +
122 (unit==null ? "unit" : unit.toLowerCase());
123 }
124
125 @Nullable
126 public String getXResolutionDescription()
127 {
128 Rational value = _directory.getRational(ExifIFD0Directory.TAG_X_RESOLUTION);
129 if (value==null)
130 return null;
131 final String unit = getResolutionDescription();
132 return value.toSimpleString(_allowDecimalRepresentationOfRationals) +
133 " dots per " +
134 (unit==null ? "unit" : unit.toLowerCase());
135 }
136
137 @Nullable
138 public String getYCbCrPositioningDescription()
139 {
140 Integer value = _directory.getInteger(ExifIFD0Directory.TAG_YCBCR_POSITIONING);
141 if (value==null)
142 return null;
143 switch (value) {
144 case 1: return "Center of pixel array";
145 case 2: return "Datum point";
146 default:
147 return String.valueOf(value);
148 }
149 }
150
151 @Nullable
152 public String getOrientationDescription()
153 {
154 Integer value = _directory.getInteger(ExifIFD0Directory.TAG_ORIENTATION);
155 if (value==null)
156 return null;
157 switch (value) {
158 case 1: return "Top, left side (Horizontal / normal)";
159 case 2: return "Top, right side (Mirror horizontal)";
160 case 3: return "Bottom, right side (Rotate 180)";
161 case 4: return "Bottom, left side (Mirror vertical)";
162 case 5: return "Left side, top (Mirror horizontal and rotate 270 CW)";
163 case 6: return "Right side, top (Rotate 90 CW)";
164 case 7: return "Right side, bottom (Mirror horizontal and rotate 90 CW)";
165 case 8: return "Left side, bottom (Rotate 270 CW)";
166 default:
167 return String.valueOf(value);
168 }
169 }
170
171 @Nullable
172 public String getResolutionDescription()
173 {
174 // '1' means no-unit, '2' means inch, '3' means centimeter. Default value is '2'(inch)
175 Integer value = _directory.getInteger(ExifIFD0Directory.TAG_RESOLUTION_UNIT);
176 if (value==null)
177 return null;
178 switch (value) {
179 case 1: return "(No unit)";
180 case 2: return "Inch";
181 case 3: return "cm";
182 default:
183 return "";
184 }
185 }
186
187 /** The Windows specific tags uses plain Unicode. */
188 @Nullable
189 private String getUnicodeDescription(int tag)
190 {
191 byte[] commentBytes = _directory.getByteArray(tag);
192 if (commentBytes==null)
193 return null;
194 try {
195 // Decode the unicode string and trim the unicode zero "\0" from the end.
196 return new String(commentBytes, "UTF-16LE").trim();
197 }
198 catch (UnsupportedEncodingException ex) {
199 return null;
200 }
201 }
202
203 @Nullable
204 public String getWindowsAuthorDescription()
205 {
206 return getUnicodeDescription(ExifIFD0Directory.TAG_WIN_AUTHOR);
207 }
208
209 @Nullable
210 public String getWindowsCommentDescription()
211 {
212 return getUnicodeDescription(ExifIFD0Directory.TAG_WIN_COMMENT);
213 }
214
215 @Nullable
216 public String getWindowsKeywordsDescription()
217 {
218 return getUnicodeDescription(ExifIFD0Directory.TAG_WIN_KEYWORDS);
219 }
220
221 @Nullable
222 public String getWindowsTitleDescription()
223 {
224 return getUnicodeDescription(ExifIFD0Directory.TAG_WIN_TITLE);
225 }
226
227 @Nullable
228 public String getWindowsSubjectDescription()
229 {
230 return getUnicodeDescription(ExifIFD0Directory.TAG_WIN_SUBJECT);
231 }
232}
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