histogram.c revision ebc891a1d9621a19c509200d7bf3470ca18dde7f 
1/*
2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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6%       H   H  IIIII  SSSSS  TTTTT   OOO    GGGG  RRRR    AAA   M   M         %
7%       H   H    I    SS       T    O   O  G      R   R  A   A  MM MM         %
8%       HHHHH    I     SSS     T    O   O  G  GG  RRRR   AAAAA  M M M         %
9%       H   H    I       SS    T    O   O  G   G  R R    A   A  M   M         %
10%       H   H  IIIII  SSSSS    T     OOO    GGG   R  R   A   A  M   M         %
11%                                                                             %
12%                                                                             %
13%                          Write A Histogram Image.                           %
14%                                                                             %
15%                              Software Design                                %
16%                                John Cristy                                  %
17%                                 July 1992                                   %
18%                                                                             %
19%                                                                             %
20%  Copyright 1999-2011 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 "magick/studio.h"
43#include "magick/property.h"
44#include "magick/blob.h"
45#include "magick/blob-private.h"
46#include "magick/cache.h"
47#include "magick/color.h"
48#include "magick/color-private.h"
49#include "magick/constitute.h"
50#include "magick/exception.h"
51#include "magick/exception-private.h"
52#include "magick/geometry.h"
53#include "magick/histogram.h"
54#include "magick/image-private.h"
55#include "magick/magick.h"
56#include "magick/memory_.h"
57#include "magick/monitor.h"
58#include "magick/monitor-private.h"
59#include "magick/option.h"
60#include "magick/resource_.h"
61#include "magick/quantum-private.h"
62#include "magick/static.h"
63#include "magick/statistic.h"
64#include "magick/string_.h"
65#include "magick/module.h"
66#include "magick/utility.h"
67
68/*
69  Forward declarations.
70*/
71static MagickBooleanType
72  WriteHISTOGRAMImage(const ImageInfo *,Image *);
73
74/*
75%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
76%                                                                             %
77%                                                                             %
78%                                                                             %
79%   R e g i s t e r H I S T O G R A M I m a g e                               %
80%                                                                             %
81%                                                                             %
82%                                                                             %
83%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
84%
85%  RegisterHISTOGRAMImage() adds attributes for the Histogram image format
86%  to the list of supported formats.  The attributes include the image format
87%  tag, a method to read and/or write the format, whether the format
88%  supports the saving of more than one frame to the same file or blob,
89%  whether the format supports native in-memory I/O, and a brief
90%  description of the format.
91%
92%  The format of the RegisterHISTOGRAMImage method is:
93%
94%      size_t RegisterHISTOGRAMImage(void)
95%
96*/
97ModuleExport size_t RegisterHISTOGRAMImage(void)
98{
99  MagickInfo
100    *entry;
101
102  entry=SetMagickInfo("HISTOGRAM");
103  entry->encoder=(EncodeImageHandler *) WriteHISTOGRAMImage;
104  entry->adjoin=MagickFalse;
105  entry->format_type=ImplicitFormatType;
106  entry->description=ConstantString("Histogram of the image");
107  entry->module=ConstantString("HISTOGRAM");
108  (void) RegisterMagickInfo(entry);
109  return(MagickImageCoderSignature);
110}
111
112/*
113%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
114%                                                                             %
115%                                                                             %
116%                                                                             %
117%   U n r e g i s t e r H I S T O G R A M I m a g e                           %
118%                                                                             %
119%                                                                             %
120%                                                                             %
121%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
122%
123%  UnregisterHISTOGRAMImage() removes format registrations made by the
124%  HISTOGRAM module from the list of supported formats.
125%
126%  The format of the UnregisterHISTOGRAMImage method is:
127%
128%      UnregisterHISTOGRAMImage(void)
129%
130*/
131ModuleExport void UnregisterHISTOGRAMImage(void)
132{
133  (void) UnregisterMagickInfo("HISTOGRAM");
134}
135
136/*
137%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
138%                                                                             %
139%                                                                             %
140%                                                                             %
141%   W r i t e H I S T O G R A M I m a g e                                     %
142%                                                                             %
143%                                                                             %
144%                                                                             %
145%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
146%
147%  WriteHISTOGRAMImage() writes an image to a file in Histogram format.
148%  The image shows a histogram of the color (or gray) values in the image.  The
149%  image consists of three overlaid histograms:  a red one for the red channel,
150%  a green one for the green channel, and a blue one for the blue channel.  The
151%  image comment contains a list of unique pixel values and the number of times
152%  each occurs in the image.
153%
154%  This method is strongly based on a similar one written by
155%  muquit@warm.semcor.com which in turn is based on ppmhistmap of netpbm.
156%
157%  The format of the WriteHISTOGRAMImage method is:
158%
159%      MagickBooleanType WriteHISTOGRAMImage(const ImageInfo *image_info,
160%        Image *image)
161%
162%  A description of each parameter follows.
163%
164%    o image_info: the image info.
165%
166%    o image:  The image.
167%
168*/
169
170static inline size_t MagickMax(const size_t x,const size_t y)
171{
172  if (x > y)
173    return(x);
174  return(y);
175}
176
177static MagickBooleanType WriteHISTOGRAMImage(const ImageInfo *image_info,
178  Image *image)
179{
180#define HistogramDensity  "256x200"
181
182  ChannelType
183    channel;
184
185  char
186    filename[MaxTextExtent];
187
188  const char
189    *option;
190
191  ExceptionInfo
192    *exception;
193
194  Image
195    *histogram_image;
196
197  ImageInfo
198    *write_info;
199
200  MagickBooleanType
201    status;
202
203  MagickPixelPacket
204    *histogram;
205
206  MagickRealType
207    maximum,
208    scale;
209
210  RectangleInfo
211    geometry;
212
213  register const PixelPacket
214    *p;
215
216  register PixelPacket
217    *q,
218    *r;
219
220  register ssize_t
221    x;
222
223  size_t
224    length;
225
226  ssize_t
227    y;
228
229  /*
230    Allocate histogram image.
231  */
232  assert(image_info != (const ImageInfo *) NULL);
233  assert(image_info->signature == MagickSignature);
234  assert(image != (Image *) NULL);
235  assert(image->signature == MagickSignature);
236  if (image->debug != MagickFalse)
237    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
238      image_info->filename);
239  SetGeometry(image,&geometry);
240  if (image_info->density == (char *) NULL)
241    (void) ParseAbsoluteGeometry(HistogramDensity,&geometry);
242  else
243    (void) ParseAbsoluteGeometry(image_info->density,&geometry);
244  histogram_image=CloneImage(image,geometry.width,geometry.height,MagickTrue,
245    &image->exception);
246  if (histogram_image == (Image *) NULL)
247    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
248  (void) SetImageStorageClass(histogram_image,DirectClass);
249  /*
250    Allocate histogram count arrays.
251  */
252  length=MagickMax((size_t) ScaleQuantumToChar((Quantum) QuantumRange)+1UL,
253    histogram_image->columns);
254  histogram=(MagickPixelPacket *) AcquireQuantumMemory(length,
255    sizeof(*histogram));
256  if (histogram == (MagickPixelPacket *) NULL)
257    {
258      histogram_image=DestroyImage(histogram_image);
259      ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
260    }
261  /*
262    Initialize histogram count arrays.
263  */
264  channel=image_info->channel;
265  (void) ResetMagickMemory(histogram,0,length*sizeof(*histogram));
266  for (y=0; y < (ssize_t) image->rows; y++)
267  {
268    p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
269    if (p == (const PixelPacket *) NULL)
270      break;
271    for (x=0; x < (ssize_t) image->columns; x++)
272    {
273      if ((channel & RedChannel) != 0)
274        histogram[ScaleQuantumToChar(GetRedPixelComponent(p))].red++;
275      if ((channel & GreenChannel) != 0)
276        histogram[ScaleQuantumToChar(GetGreenPixelComponent(p))].green++;
277      if ((channel & BlueChannel) != 0)
278        histogram[ScaleQuantumToChar(GetBluePixelComponent(p))].blue++;
279      p++;
280    }
281  }
282  maximum=histogram[0].red;
283  for (x=0; x < (ssize_t) histogram_image->columns; x++)
284  {
285    if (((channel & RedChannel) != 0) && (maximum < histogram[x].red))
286      maximum=histogram[x].red;
287    if (((channel & GreenChannel) != 0) && (maximum < histogram[x].green))
288      maximum=histogram[x].green;
289    if (((channel & BlueChannel) != 0) && (maximum < histogram[x].blue))
290      maximum=histogram[x].blue;
291  }
292  scale=(MagickRealType) histogram_image->rows/maximum;
293  /*
294    Initialize histogram image.
295  */
296  exception=(&image->exception);
297  (void) QueryColorDatabase("#000000",&histogram_image->background_color,
298    &image->exception);
299  (void) SetImageBackgroundColor(histogram_image);
300  for (x=0; x < (ssize_t) histogram_image->columns; x++)
301  {
302    q=GetAuthenticPixels(histogram_image,x,0,1,histogram_image->rows,exception);
303    if (q == (PixelPacket *) NULL)
304      break;
305    if ((channel & RedChannel) != 0)
306      {
307        y=(ssize_t) ceil(histogram_image->rows-scale*histogram[x].red-0.5);
308        r=q+y;
309        for ( ; y < (ssize_t) histogram_image->rows; y++)
310        {
311          SetRedPixelComponent(r,QuantumRange);
312          r++;
313        }
314      }
315    if ((channel & GreenChannel) != 0)
316      {
317        y=(ssize_t) ceil(histogram_image->rows-scale*histogram[x].green-0.5);
318        r=q+y;
319        for ( ; y < (ssize_t) histogram_image->rows; y++)
320        {
321          SetGreenPixelComponent(r,QuantumRange);
322          r++;
323        }
324      }
325    if ((channel & BlueChannel) != 0)
326      {
327        y=(ssize_t) ceil(histogram_image->rows-scale*histogram[x].blue-0.5);
328        r=q+y;
329        for ( ; y < (ssize_t) histogram_image->rows; y++)
330        {
331          SetBluePixelComponent(r,QuantumRange);
332          r++;
333        }
334      }
335    if (SyncAuthenticPixels(histogram_image,exception) == MagickFalse)
336      break;
337    status=SetImageProgress(image,SaveImageTag,y,histogram_image->rows);
338    if (status == MagickFalse)
339      break;
340  }
341  /*
342    Relinquish resources.
343  */
344  histogram=(MagickPixelPacket *) RelinquishMagickMemory(histogram);
345  option=GetImageOption(image_info,"histogram:unique-colors");
346  if ((option == (const char *) NULL) || (IsMagickTrue(option) != MagickFalse))
347    {
348      FILE
349        *file;
350
351      int
352        unique_file;
353
354      /*
355        Add a unique colors as an image comment.
356      */
357      file=(FILE *) NULL;
358      unique_file=AcquireUniqueFileResource(filename);
359      if (unique_file != -1)
360        file=fdopen(unique_file,"wb");
361      if ((unique_file != -1) && (file != (FILE *) NULL))
362        {
363          char
364            *property;
365
366          (void) GetNumberColors(image,file,&image->exception);
367          (void) fclose(file);
368          property=FileToString(filename,~0UL,&image->exception);
369          if (property != (char *) NULL)
370            {
371              (void) SetImageProperty(histogram_image,"comment",property);
372              property=DestroyString(property);
373            }
374        }
375      (void) RelinquishUniqueFileResource(filename);
376    }
377  /*
378    Write Histogram image.
379  */
380  (void) CopyMagickString(histogram_image->filename,image_info->filename,
381    MaxTextExtent);
382  write_info=CloneImageInfo(image_info);
383  (void) SetImageInfo(write_info,1,&image->exception);
384  if (LocaleCompare(write_info->magick,"HISTOGRAM") == 0)
385    (void) FormatMagickString(histogram_image->filename,MaxTextExtent,
386      "miff:%s",write_info->filename);
387  status=WriteImage(write_info,histogram_image);
388  histogram_image=DestroyImage(histogram_image);
389  write_info=DestroyImageInfo(write_info);
390  return(status);
391}
392