-
Notifications
You must be signed in to change notification settings - Fork 57
/
image_denoise_spmd.html
327 lines (287 loc) · 10.3 KB
/
image_denoise_spmd.html
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
<html>
<head>
<title>
IMAGE_DENOISE_SPMD - SPMD Labs Cooperate on Image Processing
</title>
</head>
<body bgcolor="#EEEEEE" link="#CC0000" alink="#FF3300" vlink="#000055">
<h1 align = "center">
IMAGE_DENOISE_SPMD <br> SPMD Labs Cooperate to Make a Plot
</h1>
<hr>
<p>
<b>IMAGE_DENOISE_SPMD</b>
is a MATLAB program which
uses the <b>SPMD</b> (single program, multiple data) command
so that multiple MATLAB workers or "labs" can cooperate in an
image processing task.
</p>
<p>
An image can be read into MATLAB using the <b>imread</b> function
in the Image Processing Toolbox. Many image processing operations
can be broken up among cooperating processors. Using the <b>spmd</b>
command, this is done most naturally by distributing the image, so
that each worker gets a separate section. Once the processing is complete,
the client copy of MATLAB can reassemble the image.
</p>
<p>
In the example considered here, a good image is damaged by the addition of
"salt and pepper" noise; that is, individual pixels have been randomly modified.
The result looks unrecognizable, but there is still a great deal of the original
information. The approach is to split the color image into R, G and B planes,
and to average the color information locally over each plane. In this way,
lone error pixels will tend to get blended away.
</p>
<p>
The function has the form:
<blockquote>
function [ x, y, z ] = image_fun ( )
</blockquote>
where the original image, "balloons.tif", is read by the function, and
<ul>
<li>
x is an array containing the original image;
</li>
<li>
y is an array containing the noisy image;
</li>
<li>
z is an array containing the filtered image;
</li>
</ul>
</p>
<p>
Depending on the situation, the function could be executed in parallel:
<ul>
<li>
interactively, and locally, using the <b>matlabpool</b> command;
</li>
<li>
indirectly, and locally, using the <b>batch</b> command;
</li>
<li>
indirectly, and on the Ithaca cluster, using the <b>batch</b> command;
</li>
<li>
indirectly, and on the FSU HPC cluster, using the <b>fsuClusterMatlab</b> command;
</li>
</ul>
</p>
<h3 align = "center">
Licensing:
</h3>
<p>
The computer code and data files described and made available on this web page
are distributed under
<a href = "../../txt/gnu_lgpl.txt">the GNU LGPL license.</a>
</p>
<h3 align = "center">
Languages:
</h3>
<p>
<b>IMAGE_DENOISE_SPMD</b> is available in
<a href = "../../m_src/image_denoise_spmd/image_denoise_spmd.html">a MATLAB version</a>.
</p>
<h3 align = "center">
Related Data and Programs:
</h3>
<p>
<a href = "../../m_src/contrast_spmd/contrast_spmd.html">
CONTRAST_SPMD</a>,
a MATLAB program which
demonstrates the SPMD parallel programming feature for image operations;
the client reads an image, the workers increase contrast over separate portions, and
the client assembles and displays the results.
</p>
<p>
<a href = "../../m_src/contrast2_spmd/contrast2_spmd.html">
CONTRAST2_SPMD</a>,
a MATLAB program which
demonstrates the SPMD parallel programming feature for image operations;
this improves the contrast_spmd program by allowing the workers to share some
data; this makes it possible to eliminate artificial "seams" in the processed
image.
</p>
<p>
<a href = "../../m_src/dijkstra_spmd/dijkstra_spmd.html">
DIJKSTRA_SPMD</a>,
a MATLAB program which
uses the SPMD feature to parallelize a simple example of Dijkstra's
minimum distance algorithm for graphs.
</p>
<p>
<a href = "../../m_src/face_spmd/face_spmd.html">
FACE_SPMD</a>,
a MATLAB program which
demonstrates the SPMD parallel programming feature;
the client has a 3D box that has been dissected into tetrahedrons.
Multiple workers cooperate to construct a list of the triangular faces
that lie on the boundaries of the box.
</p>
<p>
<a href = "../../m_src/fd2d_heat_explicit_spmd/fd2d_heat_explicit_spmd.html">
FD2D_HEAT_EXPLICIT_SPMD</a>,
a MATLAB program which
uses the finite difference method and explicit time stepping
to solve the time dependent heat equation in 2D. A black and white image
is used as the "initial condition". MATLAB's SPMD facility is used to
carry out the computation in parallel.
</p>
<p>
<a href = "../../m_src/fmincon_parallel/fmincon_parallel.html">
FMINCON_PARALLEL</a>,
a MATLAB program which
demonstrates the use of MATLAB's FMINCON constrained minimization
function, taking advantage of MATLAB's Parallel Computing Toolbox
for faster execution.
</p>
<p>
<a href = "../../m_src/image_denoise/image_denoise.html">
IMAGE_DENOISE</a>,
a MATLAB program which
applies image processing techniques to remove noise from an image.
</p>
<p>
<a href = "../../m_src/linear_solve_distributed/linear_solve_distributed.html">
LINEAR_SOLVE_DISTRIBUTED</a>,
a MATLAB program which
solves a linear system <b>A*x=b</b> using MATLAB's <b>spmd</b> facility,
so that the matrix <b>A</b> is "distributed" across multiple MATLAB workers.
</p>
<p>
<a href = "../../m_src/matlab_parallel/matlab_parallel.html">
MATLAB_PARALLEL</a>,
MATLAB programs which
illustrate "local" parallel programming on a single computer
with MATLAB's Parallel Computing Toolbox.
</p>
<p>
<a href = "../../m_src/matrix_assemble_spmd/matrix_assemble_spmd.html">
MATRIX_ASSEMBLE_SPMD</a>,
a MATLAB program which
demonstrates the SPMD parallel programming feature by having each worker
assemble part of the Hilbert matrix, which is then combined into one
array by the client program.
</p>
<p>
<a href = "../../m_src/plot_spmd/plot_spmd.html">
PLOT_SPMD</a>,
a MATLAB library which
demonstrates the SPMD parallel programming feature, by having a number
of labs compute parts of a sine plot, which is then displayed by the
client process.
</p>
<p>
<a href = "../../m_src/prime_spmd/prime_spmd.html">
PRIME_SPMD</a>,
a MATLAB program which
counts the number of primes between 1 and N;
running in parallel using MATLAB's "SPMD" feature.
</p>
<p>
<a href = "../../m_src/quad_spmd/quad_spmd.html">
QUAD_SPMD</a>,
a MATLAB program which
estimates an integral using quadrature;
running in parallel using MATLAB's "SPMD" feature.
</p>
<h3 align = "center">
Reference:
</h3>
<p>
The User's Guide for the Parallel Computing Toolbox is available at
<a href = "http://www.mathworks.com/access/helpdesk/help/pdf_doc/distcomp/distcomp.pdf">
http://www.mathworks.com/access/helpdesk/help/pdf_doc/distcomp/distcomp.pdf</a>
</p>
<p>
MathWorks documentation for the Image Processing Toolbox is available at
<a href = "http://www.mathworks.com/access/helpdesk/help/pdf_doc/images/images_tb.pdf">
http://www.mathworks.com/access/helpdesk/help/pdf_doc/images/images_tb.pdf</a>.
</p>
<p>
<ul>
<li>
Gaurav Sharma, Jos Martin,<br>
MATLAB: A Language for Parallel Computing,<br>
International Journal of Parallel Programming,<br>
Volume 37, Number 1, pages 3-36, February 2009.
</li>
</ul>
</p>
<h3 align = "center">
Source Code:
</h3>
<p>
<ul>
<li>
<a href = "image_fun.m">image_fun.m</a>,
a MATLAB function which carries out the image operation.
</li>
<li>
<a href = "image_pool.m">image_pool.m</a>
a script which uses the MATLABPOOL command to run the function locally and
interactively.
</li>
<li>
<a href = "image_script.m">image_script.m</a>,
a MATLAB script file which simply invokes the function.
</li>
<li>
<a href = "image_batch_local.m">image_batch_local.m</a>,
a batch command to run the job indirectly on the local system,
plus a few more commands
to monitor its progress, print the diary, and destroy the job at the end.
</li>
<li>
<a href = "image_batch_ithaca.m">image_batch_ithaca.m</a>,
a batch command to run the job indirectly on the Ithaca cluster,
plus a few more commands
to monitor its progress, print the diary, and destroy the job at the end.
</li>
<li>
<a href = "image_fsu.m">image_fsu.m</a>
a script which uses the fsuClusterMatlab command to run the function
indirectly on the FSU HPC cluster.
</li>
<li>
<a href = "balloons.tif">balloons.tif</a>,
a TIF image.
</li>
<li>
<a href = "balloons.png">balloons.png</a>,
a PNG version of the image.
</li>
<li>
<a href = "balloons_noisy.tif">balloons_noisy.tif</a>,
the noisy image.
</li>
<li>
<a href = "balloons_noisy.png">balloons_noisy.png</a>,
a PNG version of the image.
</li>
<li>
<a href = "balloons_filtered.tif">balloons_filtered.tif</a>,
the filtered image.
</li>
<li>
<a href = "balloons_filtered.png">balloons_filtered.png</a>,
a PNG version of the image.
</li>
<li>
<a href = "all_three.png">all_three.png</a>,
an image that shows the original picture, the noisy version, and the
filtered result.
</li>
</ul>
</p>
<p>
You can go up one level to <a href = "../m_src.html">
the MATLAB source codes</a>.
</p>
<hr>
<i>
Last revised on 28 March 2010.
</i>
<!-- John Burkardt -->
</body>
</html>