public void iterativeReconstruct() throws Exception {
Grid3D r = InitializeProjectionViews();
Grid3D q = InitializeProjectionViews();
Grid3D f = InitializeVolumeImage();
Grid3D d = InitializeVolumeImage();
Grid3D g_new = InitializeVolumeImage();
Grid3D g_old = InitializeVolumeImage();
double gamma;
double alpha;
NumericPointwiseOperators.copy(projectionViews, r);
System.out.print(
"Model-based iterative reconstruction using least-squares conjugate gradient solver: \n");
System.out.print("itn \t||r|| \t\t x(0) \t\n");
System.out.print("---------------------------------------- \n");
for (int itr = 1; itr <= maxNumOfIterations; itr++) {
if (itr <= 5 || itr % 10 == 0 || itr >= maxNumOfIterations - 5)
System.out.print(
itr
+ " \t"
+ String.format("%8.3g", NumericPointwiseOperators.dotProduct(r))
+ " \t"
+ String.format("%8.4f", f.getAtIndex(maxJ / 2, maxK / 2, maxK / 2))
+ " \n");
backproject(r, g_new);
if (itr == 1) {
gamma = 0.0;
NumericPointwiseOperators.copy(g_new, d);
} else {
gamma =
NumericPointwiseOperators.dotProduct(g_new)
/ NumericPointwiseOperators.dotProduct(g_old);
NumericPointwiseOperators.multiplyBy(d, (float) gamma);
NumericPointwiseOperators.addBy(d, g_new);
}
forwardproject(q, d);
alpha =
NumericPointwiseOperators.dotProduct(g_new, d) / NumericPointwiseOperators.dotProduct(q);
NumericGrid tmp = d.clone();
NumericPointwiseOperators.multiplyBy(tmp, (float) alpha);
NumericPointwiseOperators.addBy(f, tmp);
tmp = q.clone();
NumericPointwiseOperators.multiplyBy(tmp, (float) -alpha);
NumericPointwiseOperators.addBy(r, tmp);
NumericPointwiseOperators.copy(g_new, g_old);
}
volumeImage = f;
}
private synchronized void projectSingleProjection(int projectionNumber, int dimz) {
// load projection matrix
initProjectionMatrix(projectionNumber);
// load projection
Grid2D projection = (Grid2D) projections.get(projectionNumber).clone();
// Correct for constant part of distance weighting + For angular sampling
double D = getGeometry().getSourceToDetectorDistance();
NumericPointwiseOperators.multiplyBy(
projection, (float) (D * D * 2 * Math.PI / getGeometry().getNumProjectionMatrices()));
initProjectionData(projection);
if (!largeVolumeMode) {
projections.remove(projectionNumber);
}
// backproject for each slice
// CUDA Grids are only two dimensional!
int[] zed = new int[1];
int reconDimensionZ = dimz;
double voxelSpacingX = getGeometry().getVoxelSpacingX();
double voxelSpacingY = getGeometry().getVoxelSpacingY();
double voxelSpacingZ = getGeometry().getVoxelSpacingZ();
zed[0] = reconDimensionZ;
Pointer dOut = Pointer.to(volumePointer);
Pointer pWidth = Pointer.to(new int[] {(int) lineOffset});
Pointer pZOffset = Pointer.to(zed);
float[] vsx = new float[] {(float) voxelSpacingX};
Pointer pvsx = Pointer.to(vsx);
Pointer pvsy = Pointer.to(new float[] {(float) voxelSpacingY});
Pointer pvsz = Pointer.to(new float[] {(float) voxelSpacingZ});
Pointer pox = Pointer.to(new float[] {(float) offsetX});
Pointer poy = Pointer.to(new float[] {(float) offsetY});
Pointer poz = Pointer.to(new float[] {(float) offsetZ});
int offset = 0;
// System.out.println(dimz + " " + zed[0] + " " + offsetZ + " " + voxelSpacingZ);
offset = CUDAUtil.align(offset, Sizeof.POINTER);
JCudaDriver.cuParamSetv(function, offset, dOut, Sizeof.POINTER);
offset += Sizeof.POINTER;
offset = CUDAUtil.align(offset, Sizeof.INT);
JCudaDriver.cuParamSetv(function, offset, pWidth, Sizeof.INT);
offset += Sizeof.INT;
offset = CUDAUtil.align(offset, Sizeof.INT);
JCudaDriver.cuParamSetv(function, offset, pZOffset, Sizeof.INT);
offset += Sizeof.INT;
offset = CUDAUtil.align(offset, Sizeof.FLOAT);
JCudaDriver.cuParamSetv(function, offset, pvsx, Sizeof.FLOAT);
offset += Sizeof.FLOAT;
offset = CUDAUtil.align(offset, Sizeof.FLOAT);
JCudaDriver.cuParamSetv(function, offset, pvsy, Sizeof.FLOAT);
offset += Sizeof.FLOAT;
offset = CUDAUtil.align(offset, Sizeof.FLOAT);
JCudaDriver.cuParamSetv(function, offset, pvsz, Sizeof.FLOAT);
offset += Sizeof.FLOAT;
offset = CUDAUtil.align(offset, Sizeof.FLOAT);
JCudaDriver.cuParamSetv(function, offset, pox, Sizeof.FLOAT);
offset += Sizeof.FLOAT;
offset = CUDAUtil.align(offset, Sizeof.FLOAT);
JCudaDriver.cuParamSetv(function, offset, poy, Sizeof.FLOAT);
offset += Sizeof.FLOAT;
offset = CUDAUtil.align(offset, Sizeof.FLOAT);
JCudaDriver.cuParamSetv(function, offset, poz, Sizeof.FLOAT);
offset += Sizeof.FLOAT;
JCudaDriver.cuParamSetSize(function, offset);
// Call the CUDA kernel, writing the results into the volume which is pointed at
JCudaDriver.cuFuncSetBlockShape(function, bpBlockSize[0], bpBlockSize[1], 1);
JCudaDriver.cuLaunchGrid(function, gridSize.x, gridSize.y);
JCudaDriver.cuCtxSynchronize();
}