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| author | Willem Jan Palenstijn <Willem.Jan.Palenstijn@cwi.nl> | 2019-04-02 15:56:57 +0200 |
|---|---|---|
| committer | Willem Jan Palenstijn <Willem.Jan.Palenstijn@cwi.nl> | 2019-09-25 14:10:09 +0200 |
| commit | 975537c8c68b115399af522cb1a0a1e731eca576 (patch) | |
| tree | 4cb1d88f2e10304ef4750fa8f06fba9af5bfc1ac /cuda/2d | |
| parent | 4fba091ff811ac5e6035cf95efdaae6681e6cc46 (diff) | |
| download | astra-975537c8c68b115399af522cb1a0a1e731eca576.tar.gz astra-975537c8c68b115399af522cb1a0a1e731eca576.tar.bz2 astra-975537c8c68b115399af522cb1a0a1e731eca576.tar.xz astra-975537c8c68b115399af522cb1a0a1e731eca576.zip | |
Fix fan-beam FBP scaling
Diffstat (limited to 'cuda/2d')
| -rw-r--r-- | cuda/2d/fan_bp.cu | 11 | ||||
| -rw-r--r-- | cuda/2d/fbp.cu | 6 |
2 files changed, 9 insertions, 8 deletions
diff --git a/cuda/2d/fan_bp.cu b/cuda/2d/fan_bp.cu index 0d21897..428485c 100644 --- a/cuda/2d/fan_bp.cu +++ b/cuda/2d/fan_bp.cu @@ -271,11 +271,14 @@ __global__ void devFanBP_FBPWeighted(float* D_volData, unsigned int volPitch, un const float fNum = fDetSY * fXD - fDetSX * fYD + fX*fSrcY - fY*fSrcX; const float fDen = fDetUX * fYD - fDetUY * fXD; + const float fr = __fdividef(1.0f, fDen); + + // fDen = || u (x-s) || + // Required scale factor is ( || u s || / || u (x-s) || ) ^ 2. + // The factor || u s || ^ 2 is handled by the preweighting - const float fWeight = fXD*fXD + fYD*fYD; - - const float fT = fNum / fDen; - fVal += tex2D(gT_FanProjTexture, fT, fA) / fWeight; + const float fT = fNum * fr; + fVal += tex2D(gT_FanProjTexture, fT, fA) * fr * fr; fA += 1.0f; } diff --git a/cuda/2d/fbp.cu b/cuda/2d/fbp.cu index f0edc19..28cdd92 100644 --- a/cuda/2d/fbp.cu +++ b/cuda/2d/fbp.cu @@ -301,7 +301,7 @@ bool FBP::iterate(unsigned int iterations) astraCUDA3d::FDK_PreWeight(tmp, fOriginSource, fOriginDetector, 0.0f, - fFanDetSize, 1.0f, /* fPixelSize */ 1.0f, + fFanDetSize, 1.0f, /* fPixelSize, but is normalized */ 1.0f, m_bShortScan, dims3d, pfAngles); } else { // TODO: How should different detector pixel size in different @@ -328,9 +328,7 @@ bool FBP::iterate(unsigned int iterations) } if (fanProjs) { - float fOutputScale = 1.0 / (/*fPixelSize * fPixelSize * fPixelSize * */ fFanDetSize * fFanDetSize); - - ok = FanBP_FBPWeighted(D_volumeData, volumePitch, D_sinoData, sinoPitch, dims, fanProjs, fOutputScale * fProjectorScale * fReconstructionScale); + ok = FanBP_FBPWeighted(D_volumeData, volumePitch, D_sinoData, sinoPitch, dims, fanProjs, fProjectorScale * fReconstructionScale); } else { // scale by number of angles. For the fan-beam case, this is already |