1 /*
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 % %
4 % %
5 % %
6 % SSSSS TTTTT EEEEE GGGG AAA N N OOO %
7 % SS T E G A A NN N O O %
8 % SSS T EEE G GG AAAAA N N N O O %
9 % SS T E G G A A N NN O O %
10 % SSSSS T EEEEE GGG A A N N OOO %
11 % %
12 % %
13 % Write A Steganographic Image. %
14 % %
15 % Software Design %
16 % Cristy %
17 % July 1992 %
18 % %
19 % %
20 % Copyright 1999-2016 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
22 % %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
25 % %
26 % http://www.imagemagick.org/script/license.php %
27 % %
28 % Unless required by applicable law or agreed to in writing, software %
29 % distributed under the License is distributed on an "AS IS" BASIS, %
30 % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
31 % See the License for the specific language governing permissions and %
32 % limitations under the License. %
33 % %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
35 %
36 %
37 */
38
39 /*
40 Include declarations.
41 */
42 #include "MagickCore/studio.h"
43 #include "MagickCore/blob.h"
44 #include "MagickCore/blob-private.h"
45 #include "MagickCore/cache.h"
46 #include "MagickCore/colormap.h"
47 #include "MagickCore/constitute.h"
48 #include "MagickCore/exception.h"
49 #include "MagickCore/exception-private.h"
50 #include "MagickCore/image.h"
51 #include "MagickCore/image-private.h"
52 #include "MagickCore/list.h"
53 #include "MagickCore/magick.h"
54 #include "MagickCore/memory_.h"
55 #include "MagickCore/monitor.h"
56 #include "MagickCore/monitor-private.h"
57 #include "MagickCore/pixel-accessor.h"
58 #include "MagickCore/quantum-private.h"
59 #include "MagickCore/static.h"
60 #include "MagickCore/string_.h"
61 #include "MagickCore/module.h"
62
63 /*
64 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
65 % %
66 % %
67 % %
68 % R e a d S T E G A N O I m a g e %
69 % %
70 % %
71 % %
72 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
73 %
74 % ReadSTEGANOImage() reads a steganographic image hidden within another
75 % image type. It allocates the memory necessary for the new Image structure
76 % and returns a pointer to the new image.
77 %
78 % The format of the ReadSTEGANOImage method is:
79 %
80 % Image *ReadSTEGANOImage(const ImageInfo *image_info,
81 % ExceptionInfo *exception)
82 %
83 % A description of each parameter follows:
84 %
85 % o image_info: the image info.
86 %
87 % o exception: return any errors or warnings in this structure.
88 %
89 */
ReadSTEGANOImage(const ImageInfo * image_info,ExceptionInfo * exception)90 static Image *ReadSTEGANOImage(const ImageInfo *image_info,
91 ExceptionInfo *exception)
92 {
93 #define GetBit(alpha,i) (((size_t) (alpha) >> (size_t) (i)) & 0x01)
94 #define SetBit(i,set) SetPixelIndex(image,(Quantum) ((set) != 0 ? \
95 (size_t) GetPixelIndex(image,q) | (one << (size_t) (i)) : \
96 (size_t) GetPixelIndex(image,q) & ~(one << (size_t) (i))),q)
97
98 Image
99 *image,
100 *watermark;
101
102 ImageInfo
103 *read_info;
104
105 int
106 c;
107
108 MagickBooleanType
109 status;
110
111 PixelInfo
112 pixel;
113
114 register Quantum
115 *q;
116
117 register ssize_t
118 x;
119
120 size_t
121 depth,
122 one;
123
124 ssize_t
125 i,
126 j,
127 k,
128 y;
129
130 /*
131 Initialize Image structure.
132 */
133 assert(image_info != (const ImageInfo *) NULL);
134 assert(image_info->signature == MagickCoreSignature);
135 if (image_info->debug != MagickFalse)
136 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
137 image_info->filename);
138 assert(exception != (ExceptionInfo *) NULL);
139 assert(exception->signature == MagickCoreSignature);
140 one=1;
141 image=AcquireImage(image_info,exception);
142 if ((image->columns == 0) || (image->rows == 0))
143 ThrowReaderException(OptionError,"MustSpecifyImageSize");
144 read_info=CloneImageInfo(image_info);
145 SetImageInfoBlob(read_info,(void *) NULL,0);
146 *read_info->magick='\0';
147 watermark=ReadImage(read_info,exception);
148 read_info=DestroyImageInfo(read_info);
149 if (watermark == (Image *) NULL)
150 return((Image *) NULL);
151 watermark->depth=MAGICKCORE_QUANTUM_DEPTH;
152 if (AcquireImageColormap(image,MaxColormapSize,exception) == MagickFalse)
153 ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
154 if (image_info->ping != MagickFalse)
155 {
156 (void) CloseBlob(image);
157 return(GetFirstImageInList(image));
158 }
159 status=SetImageExtent(image,image->columns,image->rows,exception);
160 if (status == MagickFalse)
161 return(DestroyImageList(image));
162 for (y=0; y < (ssize_t) image->rows; y++)
163 {
164 q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
165 if (q == (Quantum *) NULL)
166 break;
167 for (x=0; x < (ssize_t) image->columns; x++)
168 {
169 SetPixelIndex(image,0,q);
170 q+=GetPixelChannels(image);
171 }
172 if (SyncAuthenticPixels(image,exception) == MagickFalse)
173 break;
174 }
175 /*
176 Get hidden watermark from low-order bits of image.
177 */
178 c=0;
179 i=0;
180 j=0;
181 i=(ssize_t) (watermark->depth-1);
182 depth=watermark->depth;
183 for (k=image->offset; (i >= 0) && (j < (ssize_t) depth); i--)
184 {
185 for (y=0; (y < (ssize_t) image->rows) && (j < (ssize_t) depth); y++)
186 {
187 x=0;
188 for ( ; (x < (ssize_t) image->columns) && (j < (ssize_t) depth); x++)
189 {
190 if ((k/(ssize_t) watermark->columns) >= (ssize_t) watermark->rows)
191 break;
192 (void) GetOneVirtualPixelInfo(watermark,UndefinedVirtualPixelMethod,
193 k % (ssize_t) watermark->columns,k/(ssize_t) watermark->columns,
194 &pixel,exception);
195 q=GetAuthenticPixels(image,x,y,1,1,exception);
196 if (q == (Quantum *) NULL)
197 break;
198 switch (c)
199 {
200 case 0:
201 {
202 SetBit(i,GetBit(pixel.red,j));
203 break;
204 }
205 case 1:
206 {
207 SetBit(i,GetBit(pixel.green,j));
208 break;
209 }
210 case 2:
211 {
212 SetBit(i,GetBit(pixel.blue,j));
213 break;
214 }
215 }
216 if (SyncAuthenticPixels(image,exception) == MagickFalse)
217 break;
218 c++;
219 if (c == 3)
220 c=0;
221 k++;
222 if (k == (ssize_t) (watermark->columns*watermark->columns))
223 k=0;
224 if (k == image->offset)
225 j++;
226 }
227 }
228 status=SetImageProgress(image,LoadImagesTag,(MagickOffsetType) i,depth);
229 if (status == MagickFalse)
230 break;
231 }
232 watermark=DestroyImage(watermark);
233 (void) SyncImage(image,exception);
234 return(GetFirstImageInList(image));
235 }
236
237 /*
238 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
239 % %
240 % %
241 % %
242 % R e g i s t e r S T E G A N O I m a g e %
243 % %
244 % %
245 % %
246 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
247 %
248 % RegisterSTEGANOImage() adds attributes for the STEGANO image format to
249 % the list of supported formats. The attributes include the image format
250 % tag, a method to read and/or write the format, whether the format
251 % supports the saving of more than one frame to the same file or blob,
252 % whether the format supports native in-memory I/O, and a brief
253 % description of the format.
254 %
255 % The format of the RegisterSTEGANOImage method is:
256 %
257 % size_t RegisterSTEGANOImage(void)
258 %
259 */
RegisterSTEGANOImage(void)260 ModuleExport size_t RegisterSTEGANOImage(void)
261 {
262 MagickInfo
263 *entry;
264
265 entry=AcquireMagickInfo("STEGANO","STEGANO","Steganographic image");
266 entry->decoder=(DecodeImageHandler *) ReadSTEGANOImage;
267 entry->format_type=ImplicitFormatType;
268 (void) RegisterMagickInfo(entry);
269 return(MagickImageCoderSignature);
270 }
271
272 /*
273 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
274 % %
275 % %
276 % %
277 % U n r e g i s t e r S T E G A N O I m a g e %
278 % %
279 % %
280 % %
281 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
282 %
283 % UnregisterSTEGANOImage() removes format registrations made by the
284 % STEGANO module from the list of supported formats.
285 %
286 % The format of the UnregisterSTEGANOImage method is:
287 %
288 % UnregisterSTEGANOImage(void)
289 %
290 */
UnregisterSTEGANOImage(void)291 ModuleExport void UnregisterSTEGANOImage(void)
292 {
293 (void) UnregisterMagickInfo("STEGANO");
294 }
295