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
|
/*
-----------------------------------------------------------------------
Copyright: 2010-2021, imec Vision Lab, University of Antwerp
2014-2021, CWI, Amsterdam
Contact: astra@astra-toolbox.com
Website: http://www.astra-toolbox.com/
This file is part of the ASTRA Toolbox.
The ASTRA Toolbox is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
The ASTRA Toolbox is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the ASTRA Toolbox. If not, see <http://www.gnu.org/licenses/>.
-----------------------------------------------------------------------
*/
#include "astra/GeometryUtil2D.h"
#include <cmath>
#include <cstdio>
namespace astra {
SParProjection* genParProjections(unsigned int iProjAngles,
unsigned int iProjDets,
double fDetSize,
const float *pfAngles,
const float *pfExtraOffsets)
{
SParProjection base;
base.fRayX = 0.0f;
base.fRayY = 1.0f;
base.fDetSX = iProjDets * fDetSize * -0.5f;
base.fDetSY = 0.0f;
base.fDetUX = fDetSize;
base.fDetUY = 0.0f;
SParProjection* p = new SParProjection[iProjAngles];
#define ROTATE0(name,i,alpha) do { p[i].f##name##X = base.f##name##X * cos(alpha) - base.f##name##Y * sin(alpha); p[i].f##name##Y = base.f##name##X * sin(alpha) + base.f##name##Y * cos(alpha); } while(0)
for (unsigned int i = 0; i < iProjAngles; ++i) {
if (pfExtraOffsets) {
// TODO
}
ROTATE0(Ray, i, pfAngles[i]);
ROTATE0(DetS, i, pfAngles[i]);
ROTATE0(DetU, i, pfAngles[i]);
if (pfExtraOffsets) {
float d = pfExtraOffsets[i];
p[i].fDetSX -= d * p[i].fDetUX;
p[i].fDetSY -= d * p[i].fDetUY;
}
}
#undef ROTATE0
return p;
}
SFanProjection* genFanProjections(unsigned int iProjAngles,
unsigned int iProjDets,
double fOriginSource, double fOriginDetector,
double fDetSize,
const float *pfAngles)
// const float *pfExtraOffsets)
{
SFanProjection *pProjs = new SFanProjection[iProjAngles];
float fSrcX0 = 0.0f;
float fSrcY0 = -fOriginSource;
float fDetUX0 = fDetSize;
float fDetUY0 = 0.0f;
float fDetSX0 = iProjDets * fDetUX0 / -2.0f;
float fDetSY0 = fOriginDetector;
#define ROTATE0(name,i,alpha) do { pProjs[i].f##name##X = f##name##X0 * cos(alpha) - f##name##Y0 * sin(alpha); pProjs[i].f##name##Y = f##name##X0 * sin(alpha) + f##name##Y0 * cos(alpha); } while(0)
for (unsigned int i = 0; i < iProjAngles; ++i) {
ROTATE0(Src, i, pfAngles[i]);
ROTATE0(DetS, i, pfAngles[i]);
ROTATE0(DetU, i, pfAngles[i]);
}
#undef ROTATE0
return pProjs;
}
// Convert a SParProjection back into its set of "standard" circular parallel
// beam parameters. This is always possible.
bool getParParameters(const SParProjection &proj, unsigned int iProjDets, float &fAngle, float &fDetSize, float &fOffset)
{
// Take part of DetU orthogonal to Ray
double ux = proj.fDetUX;
double uy = proj.fDetUY;
double t = (ux * proj.fRayX + uy * proj.fRayY) / (proj.fRayX * proj.fRayX + proj.fRayY * proj.fRayY);
ux -= t * proj.fRayX;
uy -= t * proj.fRayY;
double angle = atan2(uy, ux);
fAngle = (float)angle;
double norm2 = uy * uy + ux * ux;
fDetSize = (float)sqrt(norm2);
// CHECKME: SIGNS?
fOffset = (float)(-0.5*iProjDets - (proj.fDetSY*uy + proj.fDetSX*ux) / norm2);
return true;
}
// Convert a SFanProjection back into its set of "standard" circular fan beam
// parameters. This will return false if it can not be represented in this way.
bool getFanParameters(const SFanProjection &proj, unsigned int iProjDets, float &fAngle, float &fOriginSource, float &fOriginDetector, float &fDetSize, float &fOffset)
{
// angle
// det size
// offset
// origin-source
// origin-detector
// Need to check if line source-origin is orthogonal to vector ux,uy
// (including the case source==origin)
// (equivalent: source and origin project to same point on detector)
double dp = proj.fSrcX * proj.fDetUX + proj.fSrcY * proj.fDetUY;
double rel = (proj.fSrcX*proj.fSrcX + proj.fSrcY*proj.fSrcY) * (proj.fDetUX*proj.fDetUX + proj.fDetUY*proj.fDetUY);
rel = sqrt(rel);
if (std::abs(dp) > rel * 0.0001)
return false;
fOriginSource = sqrt(proj.fSrcX*proj.fSrcX + proj.fSrcY*proj.fSrcY);
fDetSize = sqrt(proj.fDetUX*proj.fDetUX + proj.fDetUY*proj.fDetUY);
// project origin on detector line ( == project source on detector line)
double t = (- proj.fDetSX) * proj.fDetUX + (- proj.fDetSY) * proj.fDetUY;
t /= (proj.fDetUX * proj.fDetUX + proj.fDetUY * proj.fDetUY);
fOffset = (float)t - 0.5*iProjDets;
fOriginDetector = sqrt((proj.fDetSX + t * proj.fDetUX)*(proj.fDetSX + t * proj.fDetUX) + (proj.fDetSY + t * proj.fDetUY)*(proj.fDetSY + t * proj.fDetUY));
fAngle = atan2(proj.fDetUY, proj.fDetUX);
//fprintf(stderr, "getFanParams: s = (%f,%f) d = (%f,%f) u = (%f,%f)\n", proj.fSrcX, proj.fSrcY, proj.fDetSX, proj.fDetSY, proj.fDetUX, proj.fDetUY);
//fprintf(stderr, "getFanParams: fOS = %f, fOD = %f, detsize = %f, offset = %f (t = %f), angle = %f\n", fOriginSource, fOriginDetector, fDetSize, fOffset, t, fAngle);
return true;
}
}
|
