if (interpType == Backprojector::INTERP_LINEAR) {
for (int i = 0; i < nDet - 1; i++)
deltaFilteredProj[i] = (filteredProj[i+1] - filteredProj[i]) * dInvScale;
if (interpType == Backprojector::INTERP_LINEAR) {
for (int i = 0; i < nDet - 1; i++)
deltaFilteredProj[i] = (filteredProj[i+1] - filteredProj[i]) * dInvScale;