1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
|
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% GGGG EEEEE M M %
% G E MM MM %
% G GG EEE M M M %
% G G E M M %
% GGGG EEEEE M M %
% %
% %
% Graphic Gems - Graphic Support Methods %
% %
% Software Design %
% Cristy %
% August 1996 %
% %
% %
% Copyright @ 1999 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
% obtain a copy of the License at %
% %
% https://imagemagick.org/script/license.php %
% %
% Unless required by applicable law or agreed to in writing, software %
% distributed under the License is distributed on an "AS IS" BASIS, %
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
% See the License for the specific language governing permissions and %
% limitations under the License. %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
%
*/
/*
Include declarations.
*/
#include "MagickCore/studio.h"
#include "MagickCore/color-private.h"
#include "MagickCore/draw.h"
#include "MagickCore/gem.h"
#include "MagickCore/gem-private.h"
#include "MagickCore/image.h"
#include "MagickCore/image-private.h"
#include "MagickCore/log.h"
#include "MagickCore/memory_.h"
#include "MagickCore/pixel-accessor.h"
#include "MagickCore/quantum.h"
#include "MagickCore/quantum-private.h"
#include "MagickCore/random_.h"
#include "MagickCore/resize.h"
#include "MagickCore/transform.h"
#include "MagickCore/signature-private.h"
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% E x p a n d A f f i n e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ExpandAffine() computes the affine's expansion factor, i.e. the square root
% of the factor by which the affine transform affects area. In an affine
% transform composed of scaling, rotation, shearing, and translation, returns
% the amount of scaling.
%
% The format of the ExpandAffine method is:
%
% double ExpandAffine(const AffineMatrix *affine)
%
% A description of each parameter follows:
%
% o expansion: ExpandAffine returns the affine's expansion factor.
%
% o affine: A pointer the affine transform of type AffineMatrix.
%
*/
MagickExport double ExpandAffine(const AffineMatrix *affine)
{
assert(affine != (const AffineMatrix *) NULL);
return(sqrt(fabs(affine->sx*affine->sy-affine->rx*affine->ry)));
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e n e r a t e D i f f e r e n t i a l N o i s e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GenerateDifferentialNoise() generates differential noise.
%
% The format of the GenerateDifferentialNoise method is:
%
% double GenerateDifferentialNoise(RandomInfo *random_info,
% const Quantum pixel,const NoiseType noise_type,const double attenuate)
%
% A description of each parameter follows:
%
% o random_info: the random info.
%
% o pixel: noise is relative to this pixel value.
%
% o noise_type: the type of noise.
%
% o attenuate: attenuate the noise.
%
*/
MagickPrivate double GenerateDifferentialNoise(RandomInfo *random_info,
const Quantum pixel,const NoiseType noise_type,const double attenuate)
{
#define SigmaUniform (attenuate*0.015625)
#define SigmaGaussian (attenuate*0.015625)
#define SigmaImpulse (attenuate*0.1)
#define SigmaLaplacian (attenuate*0.0390625)
#define SigmaMultiplicativeGaussian (attenuate*0.5)
#define SigmaPoisson (attenuate*12.5)
#define SigmaRandom (attenuate)
#define TauGaussian (attenuate*0.078125)
double
alpha,
beta,
noise,
sigma;
alpha=GetPseudoRandomValue(random_info);
switch (noise_type)
{
case UniformNoise:
default:
{
noise=(double) pixel+(double) QuantumRange*SigmaUniform*(alpha-0.5);
break;
}
case GaussianNoise:
{
double
gamma,
tau;
if (fabs(alpha) < MagickEpsilon)
alpha=1.0;
beta=GetPseudoRandomValue(random_info);
gamma=sqrt(-2.0*log(alpha));
sigma=gamma*cos((double) (2.0*MagickPI*beta));
tau=gamma*sin((double) (2.0*MagickPI*beta));
noise=(double) pixel+sqrt((double) pixel)*SigmaGaussian*sigma+
(double) QuantumRange*TauGaussian*tau;
break;
}
case ImpulseNoise:
{
if (alpha < (SigmaImpulse/2.0))
noise=0.0;
else
if (alpha >= (1.0-(SigmaImpulse/2.0)))
noise=(double) QuantumRange;
else
noise=(double) pixel;
break;
}
case LaplacianNoise:
{
if (alpha <= 0.5)
{
if (alpha <= MagickEpsilon)
noise=(double) (pixel-QuantumRange);
else
noise=(double) pixel+(double) QuantumRange*SigmaLaplacian*
log(2.0*alpha)+0.5;
break;
}
beta=1.0-alpha;
if (beta <= (0.5*MagickEpsilon))
noise=(double) (pixel+QuantumRange);
else
noise=(double) pixel-(double) QuantumRange*SigmaLaplacian*
log(2.0*beta)+0.5;
break;
}
case MultiplicativeGaussianNoise:
{
sigma=1.0;
if (alpha > MagickEpsilon)
sigma=sqrt(-2.0*log(alpha));
beta=GetPseudoRandomValue(random_info);
noise=(double) pixel+(double) pixel*SigmaMultiplicativeGaussian*sigma*
cos((double) (2.0*MagickPI*beta))/2.0;
break;
}
case PoissonNoise:
{
double
poisson;
ssize_t
i;
poisson=exp(-SigmaPoisson*QuantumScale*(double) pixel);
for (i=0; alpha > poisson; i++)
{
beta=GetPseudoRandomValue(random_info);
alpha*=beta;
}
noise=(double) QuantumRange*i*PerceptibleReciprocal(SigmaPoisson);
break;
}
case RandomNoise:
{
noise=(double) QuantumRange*SigmaRandom*alpha;
break;
}
}
return(noise);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t O p t i m a l K e r n e l W i d t h %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetOptimalKernelWidth() computes the optimal kernel radius for a convolution
% filter. Start with the minimum value of 3 pixels and walk out until we drop
% below the threshold of one pixel numerical accuracy.
%
% The format of the GetOptimalKernelWidth method is:
%
% size_t GetOptimalKernelWidth(const double radius,
% const double sigma)
%
% A description of each parameter follows:
%
% o width: GetOptimalKernelWidth returns the optimal width of a
% convolution kernel.
%
% o radius: the radius of the Gaussian, in pixels, not counting the center
% pixel.
%
% o sigma: the standard deviation of the Gaussian, in pixels.
%
*/
MagickPrivate size_t GetOptimalKernelWidth1D(const double radius,
const double sigma)
{
double
alpha,
beta,
gamma,
normalize,
value;
size_t
width;
ssize_t
i,
j;
if (IsEventLogging() != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
if (radius > MagickEpsilon)
return((size_t) (2.0*ceil(radius)+1.0));
gamma=fabs(sigma);
if (gamma <= MagickEpsilon)
return(3UL);
alpha=PerceptibleReciprocal(2.0*gamma*gamma);
beta=(double) PerceptibleReciprocal((double) MagickSQ2PI*gamma);
for (width=5; ; )
{
normalize=0.0;
j=(ssize_t) (width-1)/2;
for (i=(-j); i <= j; i++)
normalize+=exp(-((double) (i*i))*alpha)*beta;
value=exp(-((double) (j*j))*alpha)*beta/normalize;
if ((value < QuantumScale) || (value < MagickEpsilon))
break;
width+=2;
}
return((size_t) (width-2));
}
MagickPrivate size_t GetOptimalKernelWidth2D(const double radius,
const double sigma)
{
double
alpha,
beta,
gamma,
normalize,
value;
size_t
width;
ssize_t
j,
u,
v;
if (IsEventLogging() != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
if (radius > MagickEpsilon)
return((size_t) (2.0*ceil(radius)+1.0));
gamma=fabs(sigma);
if (gamma <= MagickEpsilon)
return(3UL);
alpha=PerceptibleReciprocal(2.0*gamma*gamma);
beta=(double) PerceptibleReciprocal((double) Magick2PI*gamma*gamma);
for (width=5; ; )
{
normalize=0.0;
j=(ssize_t) (width-1)/2;
for (v=(-j); v <= j; v++)
for (u=(-j); u <= j; u++)
normalize+=exp(-((double) (u*u+v*v))*alpha)*beta;
value=exp(-((double) (j*j))*alpha)*beta/normalize;
if ((value < QuantumScale) || (value < MagickEpsilon))
break;
width+=2;
}
return((size_t) (width-2));
}
MagickPrivate size_t GetOptimalKernelWidth(const double radius,
const double sigma)
{
return(GetOptimalKernelWidth1D(radius,sigma));
}
|
