1 /*
2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.imageio.plugins.jpeg;
27
28 import javax.imageio.ImageTypeSpecifier;
29 import javax.imageio.plugins.jpeg.JPEGQTable;
30 import javax.imageio.plugins.jpeg.JPEGHuffmanTable;
31
32 import java.awt.image.ColorModel;
33 import java.awt.color.ColorSpace;
34 import java.awt.color.ICC_ColorSpace;
35
36 /**
37 * A class containing JPEG-related constants, definitions, and
38 * static methods. This class and its constants must be public so that
39 * {@code JPEGImageWriteParam} can see it.
40 */
41 public class JPEG {
42
43 // List of all the JPEG markers (pre-JPEG2000)
44
45 /** For temporary use in arithmetic coding */
46 public static final int TEM = 0x01;
47
48 // Codes 0x02 - 0xBF are reserved
49
50 // SOF markers for Nondifferential Huffman coding
51 /** Baseline DCT */
52 public static final int SOF0 = 0xC0;
53 /** Extended Sequential DCT */
54 public static final int SOF1 = 0xC1;
55 /** Progressive DCT */
56 public static final int SOF2 = 0xC2;
57 /** Lossless Sequential */
58 public static final int SOF3 = 0xC3;
59
60 /** Define Huffman Tables */
61 public static final int DHT = 0xC4;
62
63 // SOF markers for Differential Huffman coding
64 /** Differential Sequential DCT */
65 public static final int SOF5 = 0xC5;
66 /** Differential Progressive DCT */
67 public static final int SOF6 = 0xC6;
68 /** Differential Lossless */
69 public static final int SOF7 = 0xC7;
70
71 /** Reserved for JPEG extensions */
72 public static final int JPG = 0xC8;
73
74 // SOF markers for Nondifferential arithmetic coding
75 /** Extended Sequential DCT, Arithmetic coding */
76 public static final int SOF9 = 0xC9;
77 /** Progressive DCT, Arithmetic coding */
78 public static final int SOF10 = 0xCA;
79 /** Lossless Sequential, Arithmetic coding */
80 public static final int SOF11 = 0xCB;
81
82 /** Define Arithmetic conditioning tables */
83 public static final int DAC = 0xCC;
84
85 // SOF markers for Differential arithmetic coding
86 /** Differential Sequential DCT, Arithmetic coding */
87 public static final int SOF13 = 0xCD;
88 /** Differential Progressive DCT, Arithmetic coding */
89 public static final int SOF14 = 0xCE;
90 /** Differential Lossless, Arithmetic coding */
91 public static final int SOF15 = 0xCF;
92
93 // Restart Markers
94 public static final int RST0 = 0xD0;
95 public static final int RST1 = 0xD1;
96 public static final int RST2 = 0xD2;
97 public static final int RST3 = 0xD3;
98 public static final int RST4 = 0xD4;
99 public static final int RST5 = 0xD5;
100 public static final int RST6 = 0xD6;
101 public static final int RST7 = 0xD7;
102 /** Number of restart markers */
103 public static final int RESTART_RANGE = 8;
104
105 /** Start of Image */
106 public static final int SOI = 0xD8;
107 /** End of Image */
108 public static final int EOI = 0xD9;
109 /** Start of Scan */
110 public static final int SOS = 0xDA;
111
112 /** Define Quantisation Tables */
113 public static final int DQT = 0xDB;
114
115 /** Define Number of lines */
116 public static final int DNL = 0xDC;
117
118 /** Define Restart Interval */
119 public static final int DRI = 0xDD;
120
121 /** Define Heirarchical progression */
122 public static final int DHP = 0xDE;
123
124 /** Expand reference image(s) */
125 public static final int EXP = 0xDF;
126
127 // Application markers
128 /** APP0 used by JFIF */
129 public static final int APP0 = 0xE0;
130 public static final int APP1 = 0xE1;
131 public static final int APP2 = 0xE2;
132 public static final int APP3 = 0xE3;
133 public static final int APP4 = 0xE4;
134 public static final int APP5 = 0xE5;
135 public static final int APP6 = 0xE6;
136 public static final int APP7 = 0xE7;
137 public static final int APP8 = 0xE8;
138 public static final int APP9 = 0xE9;
139 public static final int APP10 = 0xEA;
140 public static final int APP11 = 0xEB;
141 public static final int APP12 = 0xEC;
142 public static final int APP13 = 0xED;
143 /** APP14 used by Adobe */
144 public static final int APP14 = 0xEE;
145 public static final int APP15 = 0xEF;
146
147 // codes 0xF0 to 0xFD are reserved
148
149 /** Comment marker */
150 public static final int COM = 0xFE;
151
152 // JFIF Resolution units
153 /** The X and Y units simply indicate the aspect ratio of the pixels. */
154 public static final int DENSITY_UNIT_ASPECT_RATIO = 0;
155 /** Pixel density is in pixels per inch. */
156 public static final int DENSITY_UNIT_DOTS_INCH = 1;
157 /** Pixel density is in pixels per centemeter. */
158 public static final int DENSITY_UNIT_DOTS_CM = 2;
159 /** The max known value for DENSITY_UNIT */
160 public static final int NUM_DENSITY_UNIT = 3;
161
162 // Adobe transform values
163 public static final int ADOBE_IMPOSSIBLE = -1;
164 public static final int ADOBE_UNKNOWN = 0;
165 public static final int ADOBE_YCC = 1;
166 public static final int ADOBE_YCCK = 2;
167
168 // Spi initialization stuff
169 public static final String vendor = "Oracle Corporation";
170 public static final String version = "0.5";
171 // Names of the formats we can read or write
172 static final String [] names = {"JPEG", "jpeg", "JPG", "jpg"};
173 static final String [] suffixes = {"jpg", "jpeg"};
174 static final String [] MIMETypes = {"image/jpeg"};
175 public static final String nativeImageMetadataFormatName =
176 "javax_imageio_jpeg_image_1.0";
177 public static final String nativeImageMetadataFormatClassName =
178 "com.sun.imageio.plugins.jpeg.JPEGImageMetadataFormat";
179 public static final String nativeStreamMetadataFormatName =
180 "javax_imageio_jpeg_stream_1.0";
181 public static final String nativeStreamMetadataFormatClassName =
182 "com.sun.imageio.plugins.jpeg.JPEGStreamMetadataFormat";
183
184 // IJG Color codes.
185 public static final int JCS_UNKNOWN = 0; // error/unspecified
186 public static final int JCS_GRAYSCALE = 1; // monochrome
187 public static final int JCS_RGB = 2; // red/green/blue
188 public static final int JCS_YCbCr = 3; // Y/Cb/Cr (also known as YUV)
189 public static final int JCS_CMYK = 4; // C/M/Y/K
190 public static final int JCS_YCC = 5; // PhotoYCC
191 public static final int JCS_RGBA = 6; // RGB-Alpha
192 public static final int JCS_YCbCrA = 7; // Y/Cb/Cr/Alpha
193 // 8 and 9 were old "Legacy" codes which the old code never identified
194 // on reading anyway. Support for writing them is being dropped, too.
195 public static final int JCS_YCCA = 10; // PhotoYCC-Alpha
196 public static final int JCS_YCCK = 11; // Y/Cb/Cr/K
197
198 public static final int NUM_JCS_CODES = JCS_YCCK+1;
199
200 /** IJG can handle up to 4-channel JPEGs */
201 static final int [] [] bandOffsets = {{0},
202 {0, 1},
203 {0, 1, 2},
204 {0, 1, 2, 3}};
205
206 static final int [] bOffsRGB = { 2, 1, 0 };
207
208 /* These are kept in the inner class to avoid static initialization
209 * of the CMM class until someone actually needs it.
210 * (e.g. do not init CMM on the request for jpeg mime types)
211 */
212 public static class JCS {
213 public static final ColorSpace sRGB =
214 ColorSpace.getInstance(ColorSpace.CS_sRGB);
215
216 private static ColorSpace YCC = null;
217 private static boolean yccInited = false;
218
219 public static ColorSpace getYCC() {
220 if (!yccInited) {
221 try {
222 YCC = ColorSpace.getInstance(ColorSpace.CS_PYCC);
223 } catch (IllegalArgumentException e) {
224 // PYCC.pf may not always be installed
225 } finally {
226 yccInited = true;
227 }
228 }
229 return YCC;
230 }
231 }
232
233 // Default value for ImageWriteParam
234 public static final float DEFAULT_QUALITY = 0.75F;
235
236 /**
237 * Returns {@code true} if the given {@code ColorSpace}
238 * object is an instance of ICC_ColorSpace but is not one of the
239 * standard {@code ColorSpaces} returned by
240 * {@code ColorSpace.getInstance()}.
241 */
242 static boolean isNonStandardICC(ColorSpace cs) {
243 boolean retval = false;
244 if ((cs instanceof ICC_ColorSpace)
245 && (!cs.isCS_sRGB())
246 && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_CIEXYZ)))
247 && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_GRAY)))
248 && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_LINEAR_RGB)))
249 && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_PYCC)))
250 ) {
251 retval = true;
252 }
253 return retval;
254 }
255
256
257 /**
258 * Returns {@code true} if the given imageType can be used
259 * in a JFIF file. If {@code input} is true, then the
260 * image type is considered before colorspace conversion.
261 */
262 static boolean isJFIFcompliant(ImageTypeSpecifier imageType,
263 boolean input) {
264 ColorModel cm = imageType.getColorModel();
265 // Can't have alpha
266 if (cm.hasAlpha()) {
267 return false;
268 }
269 // Gray is OK, always
270 int numComponents = imageType.getNumComponents();
271 if (numComponents == 1) {
272 return true;
273 }
274
275 // If it isn't gray, it must have 3 channels
276 if (numComponents != 3) {
277 return false;
278 }
279
280 if (input) {
281 // Must be RGB
282 if (cm.getColorSpace().getType() == ColorSpace.TYPE_RGB) {
283 return true;
284 }
285 } else {
286 // Must be YCbCr
287 if (cm.getColorSpace().getType() == ColorSpace.TYPE_YCbCr) {
288 return true;
289 }
290 }
291
292 return false;
293 }
294
295 /**
296 * Given an image type, return the Adobe transform corresponding to
297 * that type, or ADOBE_IMPOSSIBLE if the image type is incompatible
298 * with an Adobe marker segment. If {@code input} is true, then
299 * the image type is considered before colorspace conversion.
300 */
301 static int transformForType(ImageTypeSpecifier imageType, boolean input) {
302 int retval = ADOBE_IMPOSSIBLE;
303 ColorModel cm = imageType.getColorModel();
304 switch (cm.getColorSpace().getType()) {
305 case ColorSpace.TYPE_GRAY:
306 retval = ADOBE_UNKNOWN;
307 break;
308 case ColorSpace.TYPE_RGB:
309 retval = input ? ADOBE_YCC : ADOBE_UNKNOWN;
310 break;
311 case ColorSpace.TYPE_YCbCr:
312 retval = ADOBE_YCC;
313 break;
314 case ColorSpace.TYPE_CMYK:
315 retval = input ? ADOBE_YCCK : ADOBE_IMPOSSIBLE;
316 }
317 return retval;
318 }
319
320 /**
321 * Converts an ImageWriteParam (i.e. IJG) non-linear quality value
322 * to a float suitable for passing to JPEGQTable.getScaledInstance().
323 */
324 static float convertToLinearQuality(float quality) {
325 // The following is converted from the IJG code.
326 if (quality <= 0.0F) {
327 quality = 0.01F;
328 }
329
330 if (quality > 1.00F) {
331 quality = 1.00F;
332 }
333
334 if (quality < 0.5F) {
335 quality = 0.5F / quality;
336 } else {
337 quality = 2.0F - (quality * 2.0F);
338 }
339
340 return quality;
341 }
342
343 /**
344 * Return an array of default, visually lossless quantization tables.
345 */
346 static JPEGQTable [] getDefaultQTables() {
347 JPEGQTable [] qTables = new JPEGQTable[2];
348 qTables[0] = JPEGQTable.K1Div2Luminance;
349 qTables[1] = JPEGQTable.K2Div2Chrominance;
350 return qTables;
351 }
352
353 /**
354 * Return an array of default Huffman tables.
355 */
356 static JPEGHuffmanTable [] getDefaultHuffmanTables(boolean wantDC) {
357 JPEGHuffmanTable [] tables = new JPEGHuffmanTable[2];
358 if (wantDC) {
359 tables[0] = JPEGHuffmanTable.StdDCLuminance;
360 tables[1] = JPEGHuffmanTable.StdDCChrominance;
361 } else {
362 tables[0] = JPEGHuffmanTable.StdACLuminance;
363 tables[1] = JPEGHuffmanTable.StdACChrominance;
364 }
365 return tables;
366 }
367
368 }