summaryrefslogtreecommitdiffstats
path: root/cuda/2d/fft.cu
diff options
context:
space:
mode:
Diffstat (limited to 'cuda/2d/fft.cu')
-rw-r--r--cuda/2d/fft.cu70
1 files changed, 31 insertions, 39 deletions
diff --git a/cuda/2d/fft.cu b/cuda/2d/fft.cu
index aab755a..3dd1c22 100644
--- a/cuda/2d/fft.cu
+++ b/cuda/2d/fft.cu
@@ -304,44 +304,42 @@ void genFilter(E_FBPFILTER _eFilter, float _fD, int _iProjectionCount,
float * pfFilt = new float[_iFFTFourierDetectorCount];
float * pfW = new float[_iFFTFourierDetectorCount];
-#if 1
+ // We cache one Fourier transform for repeated FBP's of the same size
+ static float *pfData = 0;
+ static int iFilterCacheSize = 0;
+
+ if (!pfData || iFilterCacheSize != _iFFTRealDetectorCount) {
+ // Compute filter in spatial domain
+
+ delete[] pfData;
+ pfData = new float[2*_iFFTRealDetectorCount];
+ int *ip = new int[int(2+sqrt(_iFFTRealDetectorCount)+1)];
+ ip[0] = 0;
+ float32 *w = new float32[_iFFTRealDetectorCount/2];
+
+ for (int i = 0; i < _iFFTRealDetectorCount; ++i) {
+ pfData[2*i+1] = 0.0f;
+
+ if (i & 1) {
+ int j = i;
+ if (2*j > _iFFTRealDetectorCount)
+ j = _iFFTRealDetectorCount - j;
+ float f = M_PI * j;
+ pfData[2*i] = -1 / (f*f);
+ } else {
+ pfData[2*i] = 0.0f;
+ }
+ }
- for(int iDetectorIndex = 0; iDetectorIndex < _iFFTFourierDetectorCount; iDetectorIndex++)
- {
- float fRelIndex = (float)iDetectorIndex / (float)_iFFTRealDetectorCount;
+ pfData[0] = 0.25f;
- // filt = 2*( 0:(order/2) )./order;
- pfFilt[iDetectorIndex] = 2.0f * fRelIndex;
- //pfFilt[iDetectorIndex] = 1.0f;
+ cdft(2*_iFFTRealDetectorCount, -1, pfData, ip, w);
+ delete[] ip;
+ delete[] w;
- // w = 2*pi*(0:size(filt,2)-1)/order
- pfW[iDetectorIndex] = 3.1415f * 2.0f * fRelIndex;
- }
-#else
-
- float *pfData = new float[2*_iFFTRealDetectorCount];
- int *ip = new int[int(2+sqrt(_iFFTRealDetectorCount)+1)];
- ip[0]=0;
- float32 *w = new float32[_iFFTRealDetectorCount/2];
-
- for (int i = 0; i < _iFFTRealDetectorCount; ++i) {
- pfData[2*i+1] = 0.0f;
-
- if (i & 1) {
- int j = i;
- if (2*j > _iFFTRealDetectorCount)
- j = _iFFTRealDetectorCount - j;
- float f = M_PI * j;
- pfData[2*i] = -1 / (f*f);
- } else {
- pfData[2*i] = 0.0f;
- }
+ iFilterCacheSize = _iFFTRealDetectorCount;
}
- pfData[0] = 0.25f;
-
- cdft(2*_iFFTRealDetectorCount, -1, pfData, ip, w);
-
for(int iDetectorIndex = 0; iDetectorIndex < _iFFTFourierDetectorCount; iDetectorIndex++)
{
float fRelIndex = (float)iDetectorIndex / (float)_iFFTRealDetectorCount;
@@ -350,11 +348,6 @@ void genFilter(E_FBPFILTER _eFilter, float _fD, int _iProjectionCount,
pfW[iDetectorIndex] = M_PI * 2.0f * fRelIndex;
}
- delete[] pfData;
- delete[] ip;
- delete[] w;
-#endif
-
switch(_eFilter)
{
case FILTER_RAMLAK:
@@ -906,5 +899,4 @@ void downloadDebugFilterReal(float * _pfHostSinogram, int _iProjectionCount,
free(pfHostFilter);
}
-
#endif