2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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 %
13 % Write A Steganographic Image. %
20 % Copyright 1999-2016 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
26 % http://www.imagemagick.org/script/license.php %
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. %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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"
64 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
68 % R e a d S T E G A N O I m a g e %
72 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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.
78 % The format of the ReadSTEGANOImage method is:
80 % Image *ReadSTEGANOImage(const ImageInfo *image_info,
81 % ExceptionInfo *exception)
83 % A description of each parameter follows:
85 % o image_info: the image info.
87 % o exception: return any errors or warnings in this structure.
90 static Image *ReadSTEGANOImage(const ImageInfo *image_info,
91 ExceptionInfo *exception)
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)
131 Initialize Image structure.
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);
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)
156 (void) CloseBlob(image);
157 return(GetFirstImageInList(image));
159 status=SetImageExtent(image,image->columns,image->rows,exception);
160 if (status == MagickFalse)
161 return(DestroyImageList(image));
163 Get hidden watermark from low-order bits of image.
168 i=(ssize_t) (watermark->depth-1);
169 depth=watermark->depth;
170 for (k=image->offset; (i >= 0) && (j < (ssize_t) depth); i--)
172 for (y=0; (y < (ssize_t) image->rows) && (j < (ssize_t) depth); y++)
175 for ( ; (x < (ssize_t) image->columns) && (j < (ssize_t) depth); x++)
177 if ((k/(ssize_t) watermark->columns) >= (ssize_t) watermark->rows)
179 (void) GetOneVirtualPixelInfo(watermark,UndefinedVirtualPixelMethod,
180 k % (ssize_t) watermark->columns,k/(ssize_t) watermark->columns,
182 q=GetAuthenticPixels(image,x,y,1,1,exception);
183 if (q == (Quantum *) NULL)
189 SetBit(i,GetBit(pixel.red,j));
194 SetBit(i,GetBit(pixel.green,j));
199 SetBit(i,GetBit(pixel.blue,j));
203 if (SyncAuthenticPixels(image,exception) == MagickFalse)
209 if (k == (ssize_t) (watermark->columns*watermark->columns))
211 if (k == image->offset)
215 status=SetImageProgress(image,LoadImagesTag,(MagickOffsetType) i,depth);
216 if (status == MagickFalse)
219 watermark=DestroyImage(watermark);
220 (void) SyncImage(image,exception);
221 return(GetFirstImageInList(image));
225 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
229 % R e g i s t e r S T E G A N O I m a g e %
233 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
235 % RegisterSTEGANOImage() adds attributes for the STEGANO image format to
236 % the list of supported formats. The attributes include the image format
237 % tag, a method to read and/or write the format, whether the format
238 % supports the saving of more than one frame to the same file or blob,
239 % whether the format supports native in-memory I/O, and a brief
240 % description of the format.
242 % The format of the RegisterSTEGANOImage method is:
244 % size_t RegisterSTEGANOImage(void)
247 ModuleExport size_t RegisterSTEGANOImage(void)
252 entry=AcquireMagickInfo("STEGANO","STEGANO","Steganographic image");
253 entry->decoder=(DecodeImageHandler *) ReadSTEGANOImage;
254 entry->format_type=ImplicitFormatType;
255 (void) RegisterMagickInfo(entry);
256 return(MagickImageCoderSignature);
260 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
264 % U n r e g i s t e r S T E G A N O I m a g e %
268 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
270 % UnregisterSTEGANOImage() removes format registrations made by the
271 % STEGANO module from the list of supported formats.
273 % The format of the UnregisterSTEGANOImage method is:
275 % UnregisterSTEGANOImage(void)
278 ModuleExport void UnregisterSTEGANOImage(void)
280 (void) UnregisterMagickInfo("STEGANO");