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-rw-r--r--cuda/2d/fan_bp.cu264
1 files changed, 112 insertions, 152 deletions
diff --git a/cuda/2d/fan_bp.cu b/cuda/2d/fan_bp.cu
index 428485c..d9d993b 100644
--- a/cuda/2d/fan_bp.cu
+++ b/cuda/2d/fan_bp.cu
@@ -48,15 +48,18 @@ const unsigned int g_anglesPerBlock = 16;
const unsigned int g_blockSliceSize = 32;
const unsigned int g_blockSlices = 16;
-const unsigned int g_MaxAngles = 2240;
+const unsigned int g_MaxAngles = 2560;
-__constant__ float gC_SrcX[g_MaxAngles];
-__constant__ float gC_SrcY[g_MaxAngles];
-__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];
+struct DevFanParams {
+ float fNumC;
+ float fNumX;
+ float fNumY;
+ float fDenC;
+ float fDenX;
+ float fDenY;
+};
+
+__constant__ DevFanParams gC_C[g_MaxAngles];
static bool bindProjDataTexture(float* data, unsigned int pitch, unsigned int width, unsigned int height, cudaTextureAddressMode mode = cudaAddressModeBorder)
@@ -75,6 +78,7 @@ static bool bindProjDataTexture(float* data, unsigned int pitch, unsigned int wi
return true;
}
+template<bool FBPWEIGHT>
__global__ void devFanBP(float* D_volData, unsigned int volPitch, unsigned int startAngle, const SDimensions dims, float fOutputScale)
{
const int relX = threadIdx.x;
@@ -99,21 +103,14 @@ __global__ void devFanBP(float* D_volData, unsigned int volPitch, unsigned int s
for (int angle = startAngle; angle < endAngle; ++angle)
{
- const float fSrcX = gC_SrcX[angle];
- const float fSrcY = gC_SrcY[angle];
- const float fDetSX = gC_DetSX[angle];
- 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 fNumC = gC_C[angle].fNumC;
+ const float fNumX = gC_C[angle].fNumX;
+ const float fNumY = gC_C[angle].fNumY;
+ const float fDenX = gC_C[angle].fDenX;
+ const float fDenY = gC_C[angle].fDenY;
- const float fNum = fDetSY * fXD - fDetSX * fYD + fX*fSrcY - fY*fSrcX;
- const float fDen = fDetUX * fYD - fDetUY * fXD;
-
- // fDen = || u (x-s) || (2x2 determinant)
+ const float fNum = fNumC + fNumX * fX + fNumY * fY;
+ const float fDen = (FBPWEIGHT ? 1.0 : gC_C[angle].fDenC) + fDenX * fX + fDenY * fY;
// Scale factor is the approximate number of rays traversing this pixel,
// given by the inverse size of a detector pixel scaled by the magnification
@@ -122,7 +119,7 @@ __global__ void devFanBP(float* D_volData, unsigned int volPitch, unsigned int s
const float fr = __fdividef(1.0f, fDen);
const float fT = fNum * fr;
- fVal += tex2D(gT_FanProjTexture, fT, fA) * fScale * fr;
+ fVal += tex2D(gT_FanProjTexture, fT, fA) * (FBPWEIGHT ? fr * fr : fr);
fA += 1.0f;
}
@@ -158,28 +155,25 @@ __global__ void devFanBP_SS(float* D_volData, unsigned int volPitch, unsigned in
for (int angle = startAngle; angle < endAngle; ++angle)
{
- const float fSrcX = gC_SrcX[angle];
- const float fSrcY = gC_SrcY[angle];
- const float fDetSX = gC_DetSX[angle];
- 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 fNumC = gC_C[angle].fNumC;
+ const float fNumX = gC_C[angle].fNumX;
+ const float fNumY = gC_C[angle].fNumY;
+ const float fDenC = gC_C[angle].fDenC;
+ const float fDenX = gC_C[angle].fDenX;
+ const float fDenY = gC_C[angle].fDenY;
// TODO: Optimize these loops...
float fX = fXb;
for (int iSubX = 0; iSubX < dims.iRaysPerPixelDim; ++iSubX) {
float fY = fYb;
for (int iSubY = 0; iSubY < dims.iRaysPerPixelDim; ++iSubY) {
- 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 fNum = fNumC + fNumX * fX + fNumY * fY;
+ const float fDen = fDenC + fDenX * fX + fDenY * fY;
const float fr = __fdividef(1.0f, fDen);
const float fT = fNum * fr;
- fVal += tex2D(gT_FanProjTexture, fT, fA) * fScale * fr;
+ fVal += tex2D(gT_FanProjTexture, fT, fA) * fr;
fY -= fSubStep;
}
fX += fSubStep;
@@ -210,79 +204,97 @@ __global__ void devFanBP_SART(float* D_volData, unsigned int volPitch, const SDi
float* volData = (float*)D_volData;
- // TODO: Constant memory vs parameters.
- const float fSrcX = gC_SrcX[0];
- const float fSrcY = gC_SrcY[0];
- const float fDetSX = gC_DetSX[0];
- const float fDetSY = gC_DetSY[0];
- const float fDetUX = gC_DetUX[0];
- const float fDetUY = gC_DetUY[0];
-
- // NB: The 'scale' constant in devBP is cancelled out by the SART weighting
+ const float fNumC = gC_C[0].fNumC;
+ const float fNumX = gC_C[0].fNumX;
+ const float fNumY = gC_C[0].fNumY;
+ const float fDenC = gC_C[0].fDenC;
+ const float fDenX = gC_C[0].fDenX;
+ const float fDenY = gC_C[0].fDenY;
- const float fXD = fSrcX - fX;
- const float fYD = fSrcY - fY;
+ const float fNum = fNumC + fNumX * fX + fNumY * fY;
+ const float fDen = fDenC + fDenX * fX + fDenY * 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 fr = __fdividef(1.0f, fDen);
+ const float fT = fNum * fr;
+ // NB: The scale constant in devBP is cancelled out by the SART weighting
const float fVal = tex2D(gT_FanProjTexture, fT, 0.5f);
volData[Y*volPitch+X] += fVal * fOutputScale;
}
-// Weighted BP for use in fan beam FBP
-// Each pixel/ray is weighted by 1/L^2 where L is the distance to the source.
-__global__ void devFanBP_FBPWeighted(float* D_volData, unsigned int volPitch, unsigned int startAngle, const SDimensions dims, float fOutputScale)
+struct Vec2 {
+ double x;
+ double y;
+ Vec2(double x_, double y_) : x(x_), y(y_) { }
+ Vec2 operator+(const Vec2 &b) const {
+ return Vec2(x + b.x, y + b.y);
+ }
+ Vec2 operator-(const Vec2 &b) const {
+ return Vec2(x - b.x, y - b.y);
+ }
+ Vec2 operator-() const {
+ return Vec2(-x, -y);
+ }
+ double norm() const {
+ return sqrt(x*x + y*y);
+ }
+};
+
+double det2(const Vec2 &a, const Vec2 &b) {
+ return a.x * b.y - a.y * b.x;
+}
+
+
+bool transferConstants(const SFanProjection* angles, unsigned int iProjAngles, bool FBP)
{
- const int relX = threadIdx.x;
- const int relY = threadIdx.y;
+ DevFanParams *p = new DevFanParams[iProjAngles];
- int endAngle = startAngle + g_anglesPerBlock;
- if (endAngle > dims.iProjAngles)
- endAngle = dims.iProjAngles;
- const int X = blockIdx.x * g_blockSlices + relX;
- const int Y = blockIdx.y * g_blockSliceSize + relY;
+ // We need three values in the kernel:
+ // projected coordinates of pixels on the detector:
+ // || x (s-d) || + ||s d|| / || u (s-x) ||
- if (X >= dims.iVolWidth || Y >= dims.iVolHeight)
- return;
+ // ray density weighting factor for the adjoint
+ // || u (s-d) || / ( |u| * || u (s-x) || )
- const float fX = ( X - 0.5f*dims.iVolWidth + 0.5f );
- const float fY = - ( Y - 0.5f*dims.iVolHeight + 0.5f );
+ // fan-beam FBP weighting factor
+ // ( || u s || / || u (s-x) || ) ^ 2
- float* volData = (float*)D_volData;
- float fVal = 0.0f;
- float fA = startAngle + 0.5f;
- // TODO: Update for new projection scaling
+ for (unsigned int i = 0; i < iProjAngles; ++i) {
+ Vec2 u(angles[i].fDetUX, angles[i].fDetUY);
+ Vec2 s(angles[i].fSrcX, angles[i].fSrcY);
+ Vec2 d(angles[i].fDetSX, angles[i].fDetSY);
- for (int angle = startAngle; angle < endAngle; ++angle)
- {
- const float fSrcX = gC_SrcX[angle];
- const float fSrcY = gC_SrcY[angle];
- const float fDetSX = gC_DetSX[angle];
- const float fDetSY = gC_DetSY[angle];
- const float fDetUX = gC_DetUX[angle];
- const float fDetUY = gC_DetUY[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 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 fT = fNum * fr;
- fVal += tex2D(gT_FanProjTexture, fT, fA) * fr * fr;
- fA += 1.0f;
+ double fScale;
+ if (!FBP) {
+ // goal: 1/fDen = || u (s-d) || / ( |u| * || u (s-x) || )
+ // fDen = ( |u| * || u (s-x) || ) / || u (s-d) ||
+ // i.e. scale = |u| / || u (s-d) ||
+
+ fScale = u.norm() / det2(u, s-d);
+ } else {
+ // goal: 1/fDen = || u s || / || u (s-x) ||
+ // fDen = || u (s-x) || / || u s ||
+ // i.e., scale = 1 / || u s ||
+
+ fScale = 1.0 / det2(u, s);
+ }
+
+ p[i].fNumC = fScale * det2(s,d);
+ p[i].fNumX = fScale * (s-d).y;
+ p[i].fNumY = -fScale * (s-d).x;
+ p[i].fDenC = fScale * det2(u, s); // == 1.0 for FBP
+ p[i].fDenX = fScale * u.y;
+ p[i].fDenY = -fScale * u.x;
}
- volData[Y*volPitch+X] += fVal * fOutputScale;
+ // TODO: Check for errors
+ cudaMemcpyToSymbol(gC_C, p, iProjAngles*sizeof(DevFanParams), 0, cudaMemcpyHostToDevice);
+
+ return true;
}
@@ -295,28 +307,9 @@ bool FanBP_internal(float* D_volumeData, unsigned int volumePitch,
bindProjDataTexture(D_projData, projPitch, dims.iProjDets, dims.iProjAngles);
- // transfer angles to constant memory
- float* tmp = new float[dims.iProjAngles];
-
-#define TRANSFER_TO_CONSTANT(name) do { for (unsigned int i = 0; i < dims.iProjAngles; ++i) tmp[i] = angles[i].f##name ; cudaMemcpyToSymbol(gC_##name, tmp, dims.iProjAngles*sizeof(float), 0, cudaMemcpyHostToDevice); } while (0)
-
- TRANSFER_TO_CONSTANT(SrcX);
- TRANSFER_TO_CONSTANT(SrcY);
- TRANSFER_TO_CONSTANT(DetSX);
- TRANSFER_TO_CONSTANT(DetSY);
- TRANSFER_TO_CONSTANT(DetUX);
- TRANSFER_TO_CONSTANT(DetUY);
-
-#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;
+ bool ok = transferConstants(angles, dims.iProjAngles, false);
+ if (!ok)
+ return false;
dim3 dimBlock(g_blockSlices, g_blockSliceSize);
dim3 dimGrid((dims.iVolWidth+g_blockSlices-1)/g_blockSlices,
@@ -329,7 +322,7 @@ bool FanBP_internal(float* D_volumeData, unsigned int volumePitch,
if (dims.iRaysPerPixelDim > 1)
devFanBP_SS<<<dimGrid, dimBlock, 0, stream>>>(D_volumeData, volumePitch, i, dims, fOutputScale);
else
- devFanBP<<<dimGrid, dimBlock, 0, stream>>>(D_volumeData, volumePitch, i, dims, fOutputScale);
+ devFanBP<false><<<dimGrid, dimBlock, 0, stream>>>(D_volumeData, volumePitch, i, dims, fOutputScale);
}
cudaThreadSynchronize();
@@ -349,29 +342,9 @@ bool FanBP_FBPWeighted_internal(float* D_volumeData, unsigned int volumePitch,
bindProjDataTexture(D_projData, projPitch, dims.iProjDets, dims.iProjAngles);
- // transfer angles to constant memory
- float* tmp = new float[dims.iProjAngles];
-
-#define TRANSFER_TO_CONSTANT(name) do { for (unsigned int i = 0; i < dims.iProjAngles; ++i) tmp[i] = angles[i].f##name ; cudaMemcpyToSymbol(gC_##name, tmp, dims.iProjAngles*sizeof(float), 0, cudaMemcpyHostToDevice); } while (0)
-
- TRANSFER_TO_CONSTANT(SrcX);
- TRANSFER_TO_CONSTANT(SrcY);
- TRANSFER_TO_CONSTANT(DetSX);
- TRANSFER_TO_CONSTANT(DetSY);
- TRANSFER_TO_CONSTANT(DetUX);
- TRANSFER_TO_CONSTANT(DetUY);
-
-#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;
+ bool ok = transferConstants(angles, dims.iProjAngles, true);
+ if (!ok)
+ return false;
dim3 dimBlock(g_blockSlices, g_blockSliceSize);
dim3 dimGrid((dims.iVolWidth+g_blockSlices-1)/g_blockSlices,
@@ -381,7 +354,7 @@ bool FanBP_FBPWeighted_internal(float* D_volumeData, unsigned int volumePitch,
cudaStreamCreate(&stream);
for (unsigned int i = 0; i < dims.iProjAngles; i += g_anglesPerBlock) {
- devFanBP_FBPWeighted<<<dimGrid, dimBlock, 0, stream>>>(D_volumeData, volumePitch, i, dims, fOutputScale);
+ devFanBP<true><<<dimGrid, dimBlock, 0, stream>>>(D_volumeData, volumePitch, i, dims, fOutputScale);
}
cudaThreadSynchronize();
@@ -402,22 +375,9 @@ bool FanBP_SART(float* D_volumeData, unsigned int volumePitch,
// only one angle
bindProjDataTexture(D_projData, projPitch, dims.iProjDets, 1, cudaAddressModeClamp);
- // transfer angle to constant memory
-#define TRANSFER_TO_CONSTANT(name) do { cudaMemcpyToSymbol(gC_##name, &(angles[angle].f##name), sizeof(float), 0, cudaMemcpyHostToDevice); } while (0)
-
- TRANSFER_TO_CONSTANT(SrcX);
- TRANSFER_TO_CONSTANT(SrcY);
- TRANSFER_TO_CONSTANT(DetSX);
- TRANSFER_TO_CONSTANT(DetSY);
- TRANSFER_TO_CONSTANT(DetUX);
- TRANSFER_TO_CONSTANT(DetUY);
-
-#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);
+ bool ok = transferConstants(angles + angle, 1, false);
+ if (!ok)
+ return false;
dim3 dimBlock(g_blockSlices, g_blockSliceSize);
dim3 dimGrid((dims.iVolWidth+g_blockSlices-1)/g_blockSlices,