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-rw-r--r--cuda/2d/fan_bp.cu62
1 files changed, 45 insertions, 17 deletions
diff --git a/cuda/2d/fan_bp.cu b/cuda/2d/fan_bp.cu
index dac3ac2..2072cd4 100644
--- a/cuda/2d/fan_bp.cu
+++ b/cuda/2d/fan_bp.cu
@@ -48,7 +48,7 @@ const unsigned int g_anglesPerBlock = 16;
const unsigned int g_blockSliceSize = 32;
const unsigned int g_blockSlices = 16;
-const unsigned int g_MaxAngles = 2560;
+const unsigned int g_MaxAngles = 2240;
__constant__ float gC_SrcX[g_MaxAngles];
__constant__ float gC_SrcY[g_MaxAngles];
@@ -56,6 +56,7 @@ __constant__ float gC_DetSX[g_MaxAngles];
__constant__ float gC_DetSY[g_MaxAngles];
__constant__ float gC_DetUX[g_MaxAngles];
__constant__ float gC_DetUY[g_MaxAngles];
+__constant__ float gC_Scale[g_MaxAngles];
static bool bindProjDataTexture(float* data, unsigned int pitch, unsigned int width, unsigned int height, cudaTextureAddressMode mode = cudaAddressModeBorder)
@@ -96,8 +97,6 @@ __global__ void devFanBP(float* D_volData, unsigned int volPitch, unsigned int s
float fVal = 0.0f;
float fA = startAngle + 0.5f;
- // TODO: Distance correction?
-
for (int angle = startAngle; angle < endAngle; ++angle)
{
const float fSrcX = gC_SrcX[angle];
@@ -106,15 +105,24 @@ __global__ void devFanBP(float* D_volData, unsigned int volPitch, unsigned int s
const float fDetSY = gC_DetSY[angle];
const float fDetUX = gC_DetUX[angle];
const float fDetUY = gC_DetUY[angle];
+ const float fScale = gC_Scale[angle];
const float fXD = fSrcX - fX;
const float fYD = fSrcY - fY;
const float fNum = fDetSY * fXD - fDetSX * fYD + fX*fSrcY - fY*fSrcX;
const float fDen = fDetUX * fYD - fDetUY * fXD;
-
- const float fT = fNum / fDen;
- fVal += tex2D(gT_FanProjTexture, fT, fA);
+
+ // fDen = || u (x-s) || (2x2 determinant)
+
+ // Scale factor is the approximate number of rays traversing this pixel,
+ // given by the inverse size of a detector pixel scaled by the magnification
+ // factor of this pixel.
+ // Magnification factor is || u (d-s) || / || u (x-s) ||
+
+ const float fr = __fdividef(1.0f, fDen);
+ const float fT = fNum * fr;
+ fVal += tex2D(gT_FanProjTexture, fT, fA) * fScale * fr;
fA += 1.0f;
}
@@ -148,8 +156,6 @@ __global__ void devFanBP_SS(float* D_volData, unsigned int volPitch, unsigned in
float fVal = 0.0f;
float fA = startAngle + 0.5f;
- // TODO: Distance correction?
-
for (int angle = startAngle; angle < endAngle; ++angle)
{
const float fSrcX = gC_SrcX[angle];
@@ -158,6 +164,7 @@ __global__ void devFanBP_SS(float* D_volData, unsigned int volPitch, unsigned in
const float fDetSY = gC_DetSY[angle];
const float fDetUX = gC_DetUX[angle];
const float fDetUY = gC_DetUY[angle];
+ const float fScale = gC_Scale[angle];
// TODO: Optimize these loops...
float fX = fXb;
@@ -169,9 +176,10 @@ __global__ void devFanBP_SS(float* D_volData, unsigned int volPitch, unsigned in
const float fNum = fDetSY * fXD - fDetSX * fYD + fX*fSrcY - fY*fSrcX;
const float fDen = fDetUX * fYD - fDetUY * fXD;
-
- const float fT = fNum / fDen;
- fVal += tex2D(gT_FanProjTexture, fT, fA);
+ const float fr = __fdividef(1.0f, fDen);
+
+ const float fT = fNum * fr;
+ fVal += tex2D(gT_FanProjTexture, fT, fA) * fScale * fr;
fY -= fSubStep;
}
fX += fSubStep;
@@ -202,8 +210,6 @@ __global__ void devFanBP_SART(float* D_volData, unsigned int volPitch, const SDi
float* volData = (float*)D_volData;
- // TODO: Distance correction?
-
// TODO: Constant memory vs parameters.
const float fSrcX = gC_SrcX[0];
const float fSrcY = gC_SrcY[0];
@@ -211,15 +217,17 @@ __global__ void devFanBP_SART(float* D_volData, unsigned int volPitch, const SDi
const float fDetSY = gC_DetSY[0];
const float fDetUX = gC_DetUX[0];
const float fDetUY = gC_DetUY[0];
+ const float fScale = gC_Scale[0];
const float fXD = fSrcX - fX;
const float fYD = fSrcY - fY;
const float fNum = fDetSY * fXD - fDetSX * fYD + fX*fSrcY - fY*fSrcX;
const float fDen = fDetUX * fYD - fDetUY * fXD;
-
- const float fT = fNum / fDen;
- const float fVal = tex2D(gT_FanProjTexture, fT, 0.5f);
+ const float fr = __fdividef(1.0f, fDen);
+
+ const float fT = fNum * fr;
+ const float fVal = tex2D(gT_FanProjTexture, fT, 0.5f) * fScale * fr;
volData[Y*volPitch+X] += fVal * fOutputScale;
}
@@ -248,7 +256,7 @@ __global__ void devFanBP_FBPWeighted(float* D_volData, unsigned int volPitch, un
float fVal = 0.0f;
float fA = startAngle + 0.5f;
- // TODO: Distance correction?
+ // TODO: Update for new projection scaling
for (int angle = startAngle; angle < endAngle; ++angle)
{
@@ -299,6 +307,13 @@ bool FanBP_internal(float* D_volumeData, unsigned int volumePitch,
#undef TRANSFER_TO_CONSTANT
+ for (unsigned int i = 0; i < dims.iProjAngles; ++i) {
+ double detsize = sqrt(angles[i].fDetUX * angles[i].fDetUX + angles[i].fDetUY * angles[i].fDetUY);
+ double scale = (angles[i].fDetUX * (angles[i].fSrcY - angles[i].fDetSY) - angles[i].fDetUY * (angles[i].fSrcX - angles[i].fDetSX)) / detsize;
+ tmp[i] = (float)scale;
+ }
+ cudaMemcpyToSymbol(gC_Scale, tmp, dims.iProjAngles*sizeof(float), 0, cudaMemcpyHostToDevice);
+
delete[] tmp;
dim3 dimBlock(g_blockSlices, g_blockSliceSize);
@@ -346,6 +361,14 @@ bool FanBP_FBPWeighted_internal(float* D_volumeData, unsigned int volumePitch,
#undef TRANSFER_TO_CONSTANT
+ for (unsigned int i = 0; i < dims.iProjAngles; ++i) {
+ double detsize = sqrt(angles[i].fDetUX * angles[i].fDetUX + angles[i].fDetUY * angles[i].fDetUY);
+ double scale = (angles[i].fDetUX * (angles[i].fSrcY - angles[i].fDetSY) - angles[i].fDetUY * (angles[i].fSrcX - angles[i].fDetSX)) / detsize;
+ tmp[i] = (float)scale;
+ }
+ cudaMemcpyToSymbol(gC_Scale, tmp, dims.iProjAngles*sizeof(float), 0, cudaMemcpyHostToDevice);
+
+
delete[] tmp;
dim3 dimBlock(g_blockSlices, g_blockSliceSize);
@@ -389,6 +412,11 @@ bool FanBP_SART(float* D_volumeData, unsigned int volumePitch,
#undef TRANSFER_TO_CONSTANT
+ double detsize = sqrt(angles[angle].fDetUX * angles[angle].fDetUX + angles[angle].fDetUY * angles[angle].fDetUY);
+ double scale = (angles[angle].fDetUX * (angles[angle].fSrcY - angles[angle].fDetSY) - angles[angle].fDetUY * (angles[angle].fSrcX - angles[angle].fDetSX)) / detsize;
+ float tmp = (float)scale;
+ cudaMemcpyToSymbol(gC_Scale, &tmp, sizeof(float), 0, cudaMemcpyHostToDevice);
+
dim3 dimBlock(g_blockSlices, g_blockSliceSize);
dim3 dimGrid((dims.iVolWidth+g_blockSlices-1)/g_blockSlices,
(dims.iVolHeight+g_blockSliceSize-1)/g_blockSliceSize);
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-20 01:25:16 +0000