X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctsim%2Fbackprojectors.cpp;h=7551ff9a1d1e99a1e65336b4e726af20c9f26a12;hp=9e350923ab4594287c868e21ee4c8f4b371bf8a0;hb=4f15a69a3150f180bd93fcbe1c87dbaca92a77ad;hpb=2d39e823ba389fc68e5317c422b55be006094252 diff --git a/libctsim/backprojectors.cpp b/libctsim/backprojectors.cpp index 9e35092..7551ff9 100644 --- a/libctsim/backprojectors.cpp +++ b/libctsim/backprojectors.cpp @@ -6,9 +6,9 @@ ** Date Started: June 2000 ** ** This is part of the CTSim program -** Copyright (C) 1983-2000 Kevin Rosenberg +** Copyright (c) 1983-2001 Kevin Rosenberg ** -** $Id: backprojectors.cpp,v 1.3 2000/06/22 10:17:28 kevin Exp $ +** $Id: backprojectors.cpp,v 1.33 2003/03/23 18:37:42 kevin Exp $ ** ** This program is free software; you can redistribute it and/or modify ** it under the terms of the GNU General Public License (version 2) as @@ -25,23 +25,104 @@ ******************************************************************************/ #include "ct.h" +#include "interpolator.h" -Backprojector::Backprojector (const Projections& proj, ImageFile& im, const char* const backprojName, const char* const interpName) +const int Backprojector::BPROJ_INVALID = -1; +const int Backprojector::BPROJ_TRIG = 0; +const int Backprojector::BPROJ_TABLE = 1; +const int Backprojector::BPROJ_DIFF = 2; +const int Backprojector::BPROJ_IDIFF = 3; + +const char* const Backprojector::s_aszBackprojectName[] = +{ + {"trig"}, + {"table"}, + {"diff"}, + {"idiff"}, +}; + +const char* const Backprojector::s_aszBackprojectTitle[] = +{ + {"Direct Trigometric"}, + {"Trigometric Table"}, + {"Difference Iteration"}, + {"Integer Difference Iteration"}, +}; + +const int Backprojector::s_iBackprojectCount = sizeof(s_aszBackprojectName) / sizeof(const char*); + +const int Backprojector::INTERP_INVALID = -1; +const int Backprojector::INTERP_NEAREST = 0; +const int Backprojector::INTERP_LINEAR = 1; +const int Backprojector::INTERP_CUBIC = 2; +const int Backprojector::INTERP_FREQ_PREINTERPOLATION = 3; +#if HAVE_BSPLINE_INTERP +const int Backprojector::INTERP_BSPLINE = 4; +const int Backprojector::INTERP_1BSPLINE = 5; +const int Backprojector::INTERP_2BSPLINE = 6; +const int Backprojector::INTERP_3BSPLINE = 7; +#endif + +const char* const Backprojector::s_aszInterpName[] = +{ + {"nearest"}, + {"linear"}, + {"cubic"}, +#if HAVE_FREQ_PREINTERP + {"freq_preinterpolationj"}, +#endif +#if HAVE_BSPLINE_INTERP + {"bspline"}, + {"1bspline"}, + {"2bspline"}, + {"3bspline"}, +#endif +}; + +const char* const Backprojector::s_aszInterpTitle[] = +{ + {"Nearest"}, + {"Linear"}, + {"Cubic"}, +#if HAVE_FREQ_PREINTERP + {"Frequency Preinterpolation"}, +#endif +#if HAVE_BSPLINE_INTERP + {"B-Spline"}, + {"B-Spline 1st Order"}, + {"B-Spline 2nd Order"}, + {"B-Spline 3rd Order"}, +#endif +}; + +const int Backprojector::s_iInterpCount = sizeof(s_aszInterpName) / sizeof(const char*); + + + +Backprojector::Backprojector (const Projections& proj, ImageFile& im, const char* const backprojName, + const char* const interpName, const int interpFactor, const ReconstructionROI* pROI) { m_fail = false; m_pBackprojectImplem = NULL; - - initBackprojector (proj, im, backprojName, interpName); + + initBackprojector (proj, im, backprojName, interpName, interpFactor, pROI); } void Backprojector::BackprojectView (const double* const viewData, const double viewAngle) { - if (m_pBackprojectImplem) + if (m_pBackprojectImplem != NULL) m_pBackprojectImplem->BackprojectView (viewData, viewAngle); } -Backprojector::~Backprojector (void) +void +Backprojector::PostProcessing() +{ + if (m_pBackprojectImplem != NULL) + m_pBackprojectImplem->PostProcessing(); +} + +Backprojector::~Backprojector () { delete m_pBackprojectImplem; } @@ -54,180 +135,227 @@ Backprojector::~Backprojector (void) // and initializes the backprojector bool -Backprojector::initBackprojector (const Projections& proj, ImageFile& im, const char* const backprojName, const char* const interpName) +Backprojector::initBackprojector (const Projections& proj, ImageFile& im, const char* const backprojName, + const char* const interpName, const int interpFactor, const ReconstructionROI* pROI) { m_nameBackproject = backprojName; m_nameInterpolation = interpName; - m_idBackproject = convertBackprojectNameToID (backprojName); - m_idInterpolation = convertInterpolationNameToID (interpName); m_pBackprojectImplem = NULL; - - if (m_idBackproject == BPROJ_INVALID || m_idInterpolation == INTERP_INVALID) { + m_idBackproject = convertBackprojectNameToID (backprojName); + if (m_idBackproject == BPROJ_INVALID) { + m_fail = true; + m_failMessage = "Invalid backprojection name "; + m_failMessage += backprojName; + } + m_idInterpolation = convertInterpNameToID (interpName); + if (m_idInterpolation == INTERP_INVALID) { + m_fail = true; + m_failMessage = "Invalid interpolation name "; + m_failMessage += interpName; + } + + if (m_fail || m_idBackproject == BPROJ_INVALID || m_idInterpolation == INTERP_INVALID) { m_fail = true; return false; } - - if (m_idBackproject == BPROJ_TRIG) - m_pBackprojectImplem = static_cast(new BackprojectTrig (proj, im, m_idInterpolation)); - else if (m_idBackproject == BPROJ_TABLE) - m_pBackprojectImplem = static_cast(new BackprojectTable (proj, im, m_idInterpolation)); - else if (m_idBackproject == BPROJ_DIFF) - m_pBackprojectImplem = static_cast(new BackprojectDiff (proj, im, m_idInterpolation)); - else if (m_idBackproject == BPROJ_DIFF2) - m_pBackprojectImplem = static_cast(new BackprojectDiff2 (proj, im, m_idInterpolation)); - else if (m_idBackproject == BPROJ_IDIFF2) - m_pBackprojectImplem = static_cast(new BackprojectIntDiff2 (proj, im, m_idInterpolation)); - else { + + if (proj.geometry() == Scanner::GEOMETRY_EQUILINEAR) + m_pBackprojectImplem = static_cast(new BackprojectEquilinear(proj, im, m_idInterpolation, interpFactor, pROI)); + else if (proj.geometry() == Scanner::GEOMETRY_EQUIANGULAR) + m_pBackprojectImplem = static_cast(new BackprojectEquiangular(proj, im, m_idInterpolation, interpFactor, pROI)); + else if (proj.geometry() == Scanner::GEOMETRY_PARALLEL) { + if (m_idBackproject == BPROJ_TRIG) + m_pBackprojectImplem = static_cast(new BackprojectTrig (proj, im, m_idInterpolation, interpFactor, pROI)); + else if (m_idBackproject == BPROJ_TABLE) + m_pBackprojectImplem = static_cast(new BackprojectTable (proj, im, m_idInterpolation, interpFactor, pROI)); + else if (m_idBackproject == BPROJ_DIFF) + m_pBackprojectImplem = static_cast(new BackprojectDiff (proj, im, m_idInterpolation, interpFactor, pROI)); + else if (m_idBackproject == BPROJ_IDIFF) + m_pBackprojectImplem = static_cast(new BackprojectIntDiff (proj, im, m_idInterpolation, interpFactor, pROI)); + } else { m_fail = true; + m_failMessage = "Unable to select a backprojection method [Backprojector::initBackprojector]"; return false; } - + return true; } -const Backprojector::BackprojectID +int Backprojector::convertBackprojectNameToID (const char* const backprojName) { - BackprojectID backprojID = BPROJ_INVALID; - - if (strcasecmp (backprojName, BPROJ_TRIG_STR) == 0) - backprojID = BPROJ_TRIG; - else if (strcasecmp (backprojName, BPROJ_TABLE_STR) == 0) - backprojID = BPROJ_TABLE; - else if (strcasecmp (backprojName, BPROJ_DIFF_STR) == 0) - backprojID = BPROJ_DIFF; - else if (strcasecmp (backprojName, BPROJ_DIFF2_STR) == 0) - backprojID = BPROJ_DIFF2; - else if (strcasecmp (backprojName, BPROJ_IDIFF2_STR) == 0) - backprojID = BPROJ_IDIFF2; - - return (backprojID); + int backprojID = BPROJ_INVALID; + + for (int i = 0; i < s_iBackprojectCount; i++) + if (strcasecmp (backprojName, s_aszBackprojectName[i]) == 0) { + backprojID = i; + break; + } + + return (backprojID); } const char* -Backprojector::convertBackprojectIDToName (const BackprojectID bprojID) +Backprojector::convertBackprojectIDToName (int bprojID) { - const char *bprojName = ""; - - if (bprojID == BPROJ_TRIG) - bprojName = BPROJ_TRIG_STR; - else if (bprojID == BPROJ_TABLE) - bprojName = BPROJ_TABLE_STR; - else if (bprojID == BPROJ_DIFF) - bprojName = BPROJ_DIFF_STR; - else if (bprojID == BPROJ_DIFF2) - bprojName = BPROJ_DIFF2_STR; - else if (bprojID == BPROJ_IDIFF2) - bprojName = BPROJ_IDIFF2_STR; - + static const char *bprojName = ""; + + if (bprojID >= 0 && bprojID < s_iBackprojectCount) + return (s_aszBackprojectName[bprojID]); + return (bprojName); } +const char* +Backprojector::convertBackprojectIDToTitle (const int bprojID) +{ + static const char *bprojTitle = ""; + + if (bprojID >= 0 && bprojID < s_iBackprojectCount) + return (s_aszBackprojectTitle[bprojID]); + + return (bprojTitle); +} -const Backprojector::InterpolationID -Backprojector::convertInterpolationNameToID (const char* const interpName) +int +Backprojector::convertInterpNameToID (const char* const interpName) { - InterpolationID interpID = INTERP_INVALID; - - if (strcasecmp (interpName, INTERP_NEAREST_STR) == 0) - interpID = INTERP_NEAREST; - else if (strcasecmp (interpName, INTERP_LINEAR_STR) == 0) - interpID = INTERP_LINEAR; -#if HAVE_BSPLINE_INTERP - else if (strcasecmp (interpName, INTERP_BSPLINE_STR) == 0) - interpID = INTERP_BSPLINE; -#endif + int interpID = INTERP_INVALID; + + for (int i = 0; i < s_iInterpCount; i++) + if (strcasecmp (interpName, s_aszInterpName[i]) == 0) { + interpID = i; + break; + } - return (interpID); + return (interpID); } - -/* NAME - * name_of_interp Return name of interpolation method - * - * SYNOPSIS - * name = name_of_interp (interp_type) - * char *name Name of interpolation method - * int interp_type Method of interpolation - * - * NOTES - * Returns NULL if interp_type is invalid - */ +const char* +Backprojector::convertInterpIDToName (const int interpID) +{ + static const char *interpName = ""; + + if (interpID >= 0 && interpID < s_iInterpCount) + return (s_aszInterpName[interpID]); + + return (interpName); +} const char* -Backprojector::convertInterpolationIDToName (const InterpolationID interpID) +Backprojector::convertInterpIDToTitle (const int interpID) { - if (interpID == INTERP_NEAREST) - return (INTERP_NEAREST_STR); - else if (interpID == INTERP_LINEAR) - return (INTERP_LINEAR_STR); -#if HAVE_BSPLINE_INTERP - else if (interpID == INTERP_BSPLINE) - return (INTERP_BSPLINE_STR); -#endif - else - return (""); + static const char *interpTitle = ""; + + if (interpID >= 0 && interpID < s_iInterpCount) + return (s_aszInterpTitle[interpID]); + + return (interpTitle); } + // CLASS IDENTICATION // Backproject // // PURPOSE // Pure virtual base class for all backprojectors. -Backproject::Backproject (const Projections& proj, ImageFile& im, const Backprojector::InterpolationID interpType) - : proj(proj), im(im), interpType(interpType) +Backproject::Backproject (const Projections& proj, ImageFile& im, int interpType, const int interpFactor, + const ReconstructionROI* pROI) +: proj(proj), im(im), interpType(interpType), m_interpFactor(interpFactor), m_bPostProcessingDone(false) { detInc = proj.detInc(); nDet = proj.nDet(); iDetCenter = (nDet - 1) / 2; // index refering to L=0 projection - rotInc = proj.rotInc(); - + rotScale = proj.rotInc(); + + if (proj.geometry() == Scanner::GEOMETRY_PARALLEL) + rotScale /= (proj.nView() * proj.rotInc() / PI); // scale by number of PI rotations + else if (proj.geometry() == Scanner::GEOMETRY_EQUIANGULAR || proj.geometry() == Scanner::GEOMETRY_EQUILINEAR) + rotScale /= (proj.nView() * proj.rotInc() / (2 * PI)); // scale by number of 2PI rotations + else + sys_error (ERR_SEVERE, "Invalid geometry type %d [Backproject::Backproject]", proj.geometry()); + v = im.getArray(); nx = im.nx(); ny = im.ny(); im.arrayDataClear(); - + xMin = -proj.phmLen() / 2; // Retangular coords of phantom xMax = xMin + proj.phmLen(); yMin = -proj.phmLen() / 2; yMax = yMin + proj.phmLen(); + + if (pROI) { + if (pROI->m_dXMin > xMin) + xMin = pROI->m_dXMin; + if (pROI->m_dXMax < xMax) + xMax = pROI->m_dXMax; + if (pROI->m_dYMin > yMin) + yMin = pROI->m_dYMin; + if (pROI->m_dYMax < yMax) + yMax = pROI->m_dYMax; + + if (xMin > xMax) { + double temp = xMin; + xMin = xMax; + xMax = temp; + } + if (yMin > yMax) { + double temp = yMin; + yMin = yMax; + yMax = temp; + } + } xInc = (xMax - xMin) / nx; // size of cells yInc = (yMax - yMin) / ny; + + im.setAxisIncrement (xInc, yInc); + im.setAxisExtent (xMin, xMax, yMin, yMax); - if (interpType != Backprojector::INTERP_NEAREST && interpType != Backprojector::INTERP_LINEAR) - sys_error (ERR_WARNING, "Illegal interpType %d [selectBackprojector]", interpType); + m_dFocalLength = proj.focalLength(); + m_dSourceDetectorLength = proj.sourceDetectorLength(); } -Backproject::~Backproject (void) +Backproject::~Backproject () {} void -Backproject::ScaleImageByRotIncrement (void) +Backproject::PostProcessing() +{ + m_bPostProcessingDone = true; +} + +void +Backproject::ScaleImageByRotIncrement () { for (int ix = 0; ix < nx; ix++) for (int iy = 0; iy < ny; iy++) - v[ix][iy] *= rotInc; + v[ix][iy] *= rotScale; } void Backproject::errorIndexOutsideDetector (int ix, int iy, double theta, double r, double phi, double L, int iDetPos) { - printf ("r=%f, phi=%f\n", r, phi); - errorIndexOutsideDetector (ix, iy, theta, L, iDetPos); + sys_error (ERR_WARNING, "r=%f, phi=%f", r, phi); + errorIndexOutsideDetector (ix, iy, theta, L, iDetPos); } void Backproject::errorIndexOutsideDetector (int ix, int iy, double theta, double L, int iDetPos) { - printf ("ix=%d, iy=%d\n", ix, iy); - printf ("theta=%f, L=%f, detInc=%f\n", theta, L, detInc); - printf ("proj.ndet=%d, proj.detInc=%.4f, iDetCenter=%d\n", nDet, detInc, iDetCenter); - printf ("xMin=%15.8f, xMax=%15.8f, xInc=%15.8f\n", xMin, xMax, xInc); - printf ("yMin=%15.8f, yMax=%15.8f, yInc=%15.8f\n", yMin, yMax, yInc); - sys_error (ERR_WARNING, "iDetPos index outside bounds: %d [backprojector]", iDetPos); +#if 1 + std::ostringstream os; + os << "ix=" << ix << ", iy=" << iy << ", theta=" << theta << ", L=" << L << ", detinc=" << detInc << "\n"; + os << "ndet=" << nDet << ", detInc=" << detInc << ", iDetCenter=" << iDetCenter << "\n"; + os << "xMin=" << xMin << ", xMax=" << xMax << ", xInc=" << xInc << "\n"; + os << "yMin=" << yMin << ", yMax=" << yMax << ", yInc=" << yInc << "\n"; + os << "iDetPos index outside bounds: " << iDetPos << " [backprojector]";; + + sys_error (ERR_WARNING, os.str().c_str()); +#endif } @@ -240,34 +368,42 @@ void Backproject::errorIndexOutsideDetector (int ix, int iy, double theta, doubl void BackprojectTrig::BackprojectView (const double* const filteredProj, const double view_angle) { - double theta = HALFPI + view_angle; // Add PI/2 to get perpendicular angle to detector - int ix, iy; - double x, y; // Rectang coords of center of pixel - - for (x = xMin + xInc / 2, ix = 0; ix < nx; x += xInc, ix++) - for (y = yMin + yInc / 2, iy = 0; iy < ny; y += yInc, iy++) { + double theta = view_angle; + + CubicPolyInterpolator* pCubicInterp = NULL; + if (interpType == Backprojector::INTERP_CUBIC) + pCubicInterp = new CubicPolyInterpolator (filteredProj, nDet); + + double x = xMin + xInc / 2; // Rectang coords of center of pixel + for (int ix = 0; ix < nx; x += xInc, ix++) { + double y = yMin + yInc / 2; + for (int iy = 0; iy < ny; y += yInc, iy++) { double r = sqrt (x * x + y * y); // distance of cell from center double phi = atan2 (y, x); // angle of cell from center double L = r * cos (theta - phi); // position on detector - + if (interpType == Backprojector::INTERP_NEAREST) { - int iDetPos = iDetCenter + nearest (L / detInc); // calc'd index in the filter raysum array - - if (iDetPos < 0 || iDetPos >= nDet) // check for impossible: index outside of raysum pos - errorIndexOutsideDetector (ix, iy, theta, r, phi, L, iDetPos); - else - v[ix][iy] += rotInc * filteredProj[iDetPos]; + int iDetPos = iDetCenter + nearest (L / detInc); // calc'd index in the filter raysum array + + if (iDetPos >= 0 && iDetPos < nDet) + v[ix][iy] += rotScale * filteredProj[iDetPos]; } else if (interpType == Backprojector::INTERP_LINEAR) { - double p = L / detInc; // position along detector - double pFloor = floor (p); - int iDetPos = iDetCenter + static_cast(pFloor); - double frac = p - pFloor; // fraction distance from det - if (iDetPos < 0 || iDetPos >= nDet - 1) // check for impossible: index outside of raysum pos - errorIndexOutsideDetector (ix, iy, theta, r, phi, L, iDetPos); - else - v[ix][iy] += rotInc * ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]); + double p = L / detInc; // position along detector + double pFloor = floor (p); + int iDetPos = iDetCenter + static_cast(pFloor); + double frac = p - pFloor; // fraction distance from det + if (iDetPos >= 0 && iDetPos < nDet - 1) + v[ix][iy] += rotScale * ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]); + } else if (interpType == Backprojector::INTERP_CUBIC) { + double p = iDetCenter + (L / detInc); // position along detector + if (p >= 0 && p < nDet) + v[ix][iy] += rotScale * pCubicInterp->interpolate (p); } } + } + + if (interpType == Backprojector::INTERP_CUBIC) + delete pCubicInterp; } @@ -277,14 +413,15 @@ BackprojectTrig::BackprojectView (const double* const filteredProj, const double // PURPOSE // Precalculates trigometric function value for each point in image for backprojection. -BackprojectTable::BackprojectTable (const Projections& proj, ImageFile& im, Backprojector::InterpolationID interpType) - : Backproject::Backproject (proj, im, interpType) +BackprojectTable::BackprojectTable (const Projections& proj, ImageFile& im, int interpType, + const int interpFactor, const ReconstructionROI* pROI) +: Backproject (proj, im, interpType, interpFactor, pROI) { - arrayR.initSetSize (nx, ny); - arrayPhi.initSetSize (nx, ny); + arrayR.initSetSize (im.nx(), im.ny()); + arrayPhi.initSetSize (im.nx(), im.ny()); r = arrayR.getArray(); phi = arrayPhi.getArray(); - + double x, y; // Rectang coords of center of pixel int ix, iy; for (x = xMin + xInc / 2, ix = 0; ix < nx; x += xInc, ix++) @@ -294,41 +431,56 @@ BackprojectTable::BackprojectTable (const Projections& proj, ImageFile& im, Back } } -BackprojectTable::~BackprojectTable (void) +BackprojectTable::~BackprojectTable () { - ScaleImageByRotIncrement(); } void -BackprojectTable::BackprojectView (const double* const filteredProj, const double view_angle) +BackprojectTable::PostProcessing() { - double theta = HALFPI + view_angle; // add half PI to view angle to get perpendicular theta angle + if (! m_bPostProcessingDone) { + ScaleImageByRotIncrement(); + m_bPostProcessingDone = true; + } +} +void +BackprojectTable::BackprojectView (const double* const filteredProj, const double view_angle) +{ + double theta = view_angle; + + CubicPolyInterpolator* pCubicInterp = NULL; + if (interpType == Backprojector::INTERP_CUBIC) + pCubicInterp = new CubicPolyInterpolator (filteredProj, nDet); + for (int ix = 0; ix < nx; ix++) { ImageFileColumn pImCol = v[ix]; - + for (int iy = 0; iy < ny; iy++) { double L = r[ix][iy] * cos (theta - phi[ix][iy]); - + if (interpType == Backprojector::INTERP_NEAREST) { - int iDetPos = iDetCenter + nearest(L / detInc); // calc index in the filtered raysum vector - - if (iDetPos < 0 || iDetPos >= nDet) // check for impossible: index outside of raysum pos - errorIndexOutsideDetector (ix, iy, theta, r[ix][iy], phi[ix][iy], L, iDetPos); - else - pImCol[iy] += filteredProj[iDetPos]; + int iDetPos = iDetCenter + nearest(L / detInc); // calc index in the filtered raysum vector + + if (iDetPos >= 0 && iDetPos < nDet) + pImCol[iy] += filteredProj[iDetPos]; } else if (interpType == Backprojector::INTERP_LINEAR) { - double dPos = L / detInc; // position along detector - double dPosFloor = floor (dPos); - int iDetPos = iDetCenter + static_cast(dPosFloor); - double frac = dPos - dPosFloor; // fraction distance from det - if (iDetPos < 0 || iDetPos >= nDet - 1) - errorIndexOutsideDetector (ix, iy, theta, r[ix][iy], phi[ix][iy], L, iDetPos); - else - pImCol[iy] += ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]); + double dPos = L / detInc; // position along detector + double dPosFloor = floor (dPos); + int iDetPos = iDetCenter + static_cast(dPosFloor); + double frac = dPos - dPosFloor; // fraction distance from det + if (iDetPos >= 0 && iDetPos < nDet - 1) + pImCol[iy] += ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]); + } else if (interpType == Backprojector::INTERP_CUBIC) { + double p = iDetCenter + (L / detInc); // position along detector + if (p >= 0 && p < nDet) + pImCol[iy] += pCubicInterp->interpolate (p); } } // end for y } // end for x + + if (interpType == Backprojector::INTERP_CUBIC) + delete pCubicInterp; } @@ -339,158 +491,235 @@ BackprojectTable::BackprojectView (const double* const filteredProj, const doubl // Backprojects by precalculating the change in L position for each x & y step in the image. // Iterates in x & y direction by adding difference in L position -BackprojectDiff::BackprojectDiff (const Projections& proj, ImageFile& im, Backprojector::InterpolationID interpType) - : Backproject::Backproject (proj, im, interpType) +BackprojectDiff::BackprojectDiff (const Projections& proj, ImageFile& im, int interpType, + const int interpFactor, const ReconstructionROI* pROI) +: Backproject (proj, im, interpType, interpFactor, pROI) { // calculate center of first pixel v[0][0] double x = xMin + xInc / 2; double y = yMin + yInc / 2; start_r = sqrt (x * x + y * y); start_phi = atan2 (y, x); - + im.arrayDataClear(); } -BackprojectDiff::~BackprojectDiff() +BackprojectDiff::~BackprojectDiff () { - ScaleImageByRotIncrement(); } void -BackprojectDiff::BackprojectView (const double* const filteredProj, const double view_angle) +BackprojectDiff::PostProcessing() { - double theta = - view_angle; // add half PI to view angle to get perpendicular theta angle - double det_dx = xInc * sin (theta); - double det_dy = yInc * cos (theta); - double lColStart = start_r * cos (theta - start_phi); // calculate L for first point in image - - for (int ix = 0; ix < nx; ix++, lColStart += det_dx) { - double curDetPos = lColStart; - ImageFileColumn pImCol = v[ix]; - - for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) { -#ifdef DEBUG - printf ("[%2d,%2d]: %8.5lf ", ix, iy, curDetPos); -#endif - if (interpType == Backprojector::INTERP_NEAREST) { - int iDetPos = iDetCenter + nearest(curDetPos / detInc); // calc index in the filtered raysum vector - - if (iDetPos < 0 || iDetPos >= nDet) // check for impossible: index outside of raysum pos - errorIndexOutsideDetector (ix, iy, theta, curDetPos, iDetPos); - else - pImCol[iy] += filteredProj[iDetPos]; - } else if (interpType == Backprojector::INTERP_LINEAR) { - double detPos = curDetPos / detInc; // position along detector - double detPosFloor = floor (detPos); - int iDetPos = iDetCenter + static_cast(detPosFloor); - double frac = detPos - detPosFloor; // fraction distance from det - if (iDetPos < 0 || iDetPos >= nDet - 1) - errorIndexOutsideDetector (ix, iy, theta, curDetPos, iDetPos); - else - pImCol[iy] += ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]); - } - } // end for y - } // end for x + if (! m_bPostProcessingDone) { + ScaleImageByRotIncrement(); + m_bPostProcessingDone = true; + } } - -// CLASS IDENTICATION -// BackprojectDiff2 -// -// PURPOSE -// Optimized version of BackprojectDiff - void -BackprojectDiff2::BackprojectView (const double* const filteredProj, const double view_angle) +BackprojectDiff::BackprojectView (const double* const filteredProj, const double view_angle) { - double theta = - view_angle; // add half PI to view angle to get perpendicular theta angle - - // Distance betw. detectors for an angle given in units of detectors - double det_dx = xInc * sin (theta) / detInc; - double det_dy = yInc * cos (theta) / detInc; - + double theta = view_angle; + + // Distance between detectors for an angle given in units of detectors + double det_dx = xInc * cos (theta) / detInc; + double det_dy = yInc * sin (theta) / detInc; + // calculate detPosition for first point in image (ix=0, iy=0) double detPosColStart = start_r * cos (theta - start_phi) / detInc; - -#ifdef DEBUG - printf ("start_r=%8.5f, start_phi=%8.5f, rotInc=%8.5f\n", start_r, start_phi, rotInc); -#endif + + CubicPolyInterpolator* pCubicInterp = NULL; + if (interpType == Backprojector::INTERP_CUBIC) + pCubicInterp = new CubicPolyInterpolator (filteredProj, nDet); + for (int ix = 0; ix < nx; ix++, detPosColStart += det_dx) { double curDetPos = detPosColStart; ImageFileColumn pImCol = v[ix]; - + for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) { -#ifdef DEBUG - printf ("[%2d,%2d]: %8.5f %8.5f\n", ix, iy, curDetPos, filteredProj[iDetCenter + nearest(L))]); -#endif if (interpType == Backprojector::INTERP_NEAREST) { - int iDetPos = iDetCenter + nearest (curDetPos); // calc index in the filtered raysum vector - - if (iDetPos < 0 || iDetPos >= nDet) // check for impossible: index outside of raysum pos - errorIndexOutsideDetector (ix, iy, theta, curDetPos, iDetPos); - else - *pImCol++ += filteredProj[iDetPos]; + int iDetPos = iDetCenter + nearest (curDetPos); // calc index in the filtered raysum vector + + if (iDetPos >= 0 && iDetPos < nDet) + *pImCol++ += filteredProj[iDetPos]; } else if (interpType == Backprojector::INTERP_LINEAR) { - double detPosFloor = floor (curDetPos); - int iDetPos = iDetCenter + static_cast(detPosFloor); - double frac = curDetPos - detPosFloor; // fraction distance from det - if (iDetPos < 0 || iDetPos >= nDet - 1) - errorIndexOutsideDetector (ix, iy, theta, curDetPos, iDetPos); - else - *pImCol++ += ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]); + double detPosFloor = floor (curDetPos); + int iDetPos = iDetCenter + static_cast(detPosFloor); + double frac = curDetPos - detPosFloor; // fraction distance from det + if (iDetPos > 0 && iDetPos < nDet - 1) + *pImCol++ += filteredProj[iDetPos] + (frac * (filteredProj[iDetPos+1] - filteredProj[iDetPos])); + } else if (interpType == Backprojector::INTERP_CUBIC) { + double p = iDetCenter + curDetPos; // position along detector + if (p >= 0 && p < nDet) + *pImCol++ += pCubicInterp->interpolate (p); } } // end for y } // end for x + + if (interpType == Backprojector::INTERP_CUBIC) + delete pCubicInterp; } + // CLASS IDENTICATION -// BackprojectIntDiff2 +// BackprojectIntDiff // // PURPOSE -// Integer version of BackprojectDiff2 +// Highly optimized and integer version of BackprojectDiff void -BackprojectIntDiff2::BackprojectView (const double* const filteredProj, const double view_angle) +BackprojectIntDiff::BackprojectView (const double* const filteredProj, const double view_angle) { - double theta = - view_angle; // add half PI to view angle to get perpendicular theta angle - - kint32 scale = 1 << 16; - double dScale = scale; - kint32 halfScale = scale / 2; - - kint32 det_dx = nearest (xInc * sin (theta) / detInc * scale); - kint32 det_dy = nearest (yInc * cos (theta) / detInc * scale); - + double theta = view_angle; // add half PI to view angle to get perpendicular theta angle + static const int scaleShift = 16; + static const kint32 scale = (1 << scaleShift); + static const kint32 scaleBitmask = scale - 1; + static const kint32 halfScale = scale / 2; + static const double dInvScale = 1. / scale; + + const kint32 det_dx = nearest (xInc * cos (theta) / detInc * scale); + const kint32 det_dy = nearest (yInc * sin (theta) / detInc * scale); + // calculate L for first point in image (0, 0) - kint32 detPosColStart = nearest (start_r * cos (theta - start_phi) / detInc * scale); - + kint32 detPosColStart = nearest ((start_r * cos (theta - start_phi) / detInc + iDetCenter) * scale); + + double* deltaFilteredProj = NULL; + CubicPolyInterpolator* pCubicInterp = NULL; + if (interpType == Backprojector::INTERP_LINEAR) { + // precalculate scaled difference for linear interpolation + deltaFilteredProj = new double [nDet]; + for (int i = 0; i < nDet - 1; i++) + deltaFilteredProj[i] = (filteredProj[i+1] - filteredProj[i]) * dInvScale; + deltaFilteredProj[nDet - 1] = 0; // last detector + } else if (interpType == Backprojector::INTERP_CUBIC) { + pCubicInterp = new CubicPolyInterpolator (filteredProj, nDet); + } + + int iLastDet = nDet - 1; for (int ix = 0; ix < nx; ix++, detPosColStart += det_dx) { kint32 curDetPos = detPosColStart; ImageFileColumn pImCol = v[ix]; + + if (interpType == Backprojector::INTERP_NEAREST) { + for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) { + const int iDetPos = (curDetPos + halfScale) >> 16; + if (iDetPos >= 0 && iDetPos <= iLastDet) + *pImCol++ += filteredProj[iDetPos]; + } // end for iy + } else if (interpType == Backprojector::INTERP_FREQ_PREINTERPOLATION) { + for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) { + const int iDetPos = ((curDetPos + halfScale) >> 16) * m_interpFactor; + if (iDetPos >= 0 && iDetPos <= iLastDet) + *pImCol++ += filteredProj[iDetPos]; + } // end for iy + } else if (interpType == Backprojector::INTERP_LINEAR) { + for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) { + const kint32 iDetPos = curDetPos >> scaleShift; + const kint32 detRemainder = curDetPos & scaleBitmask; + if (iDetPos >= 0 && iDetPos <= iLastDet) + *pImCol++ += filteredProj[iDetPos] + (detRemainder * deltaFilteredProj[iDetPos]); + } // end for iy + } else if (interpType == Backprojector::INTERP_CUBIC) { + for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) { + *pImCol++ += pCubicInterp->interpolate (static_cast(curDetPos) / 65536); + } + } // end Cubic + } // end for ix + + if (interpType == Backprojector::INTERP_LINEAR) + delete deltaFilteredProj; + else if (interpType == Backprojector::INTERP_CUBIC) + delete pCubicInterp; +} - for (int iy = 0; iy < ny; iy++, curDetPos += det_dy) { + +void +BackprojectEquiangular::BackprojectView (const double* const filteredProj, const double view_angle) +{ + double beta = view_angle; + + CubicPolyInterpolator* pCubicInterp = NULL; + if (interpType == Backprojector::INTERP_CUBIC) + pCubicInterp = new CubicPolyInterpolator (filteredProj, nDet); + + for (int ix = 0; ix < nx; ix++) { + ImageFileColumn pImCol = v[ix]; + + for (int iy = 0; iy < ny; iy++) { + double dAngleDiff = beta - phi[ix][iy]; + double rcos_t = r[ix][iy] * cos (dAngleDiff); + double rsin_t = r[ix][iy] * sin (dAngleDiff); + double dFLPlusSin = m_dFocalLength + rsin_t; + double gamma = atan (rcos_t / dFLPlusSin); + double dPos = gamma / detInc; // position along detector + double dL2 = dFLPlusSin * dFLPlusSin + (rcos_t * rcos_t); + if (interpType == Backprojector::INTERP_NEAREST) { - int detPosNearest = (curDetPos >= 0 ? ((curDetPos + halfScale) / scale) : ((curDetPos - halfScale) / scale)); - int iDetPos = iDetCenter + detPosNearest; // calc index in the filtered raysum vector + int iDetPos = iDetCenter + nearest(dPos); // calc index in the filtered raysum vector + if (iDetPos >= 0 && iDetPos < nDet) + pImCol[iy] += filteredProj[iDetPos] / dL2; + } else if (interpType == Backprojector::INTERP_LINEAR) { + double dPosFloor = floor (dPos); + int iDetPos = iDetCenter + static_cast(dPosFloor); + double frac = dPos - dPosFloor; // fraction distance from det + if (iDetPos >= 0 && iDetPos < nDet - 1) + pImCol[iy] += (filteredProj[iDetPos] + frac * (filteredProj[iDetPos+1] - filteredProj[iDetPos])) / dL2; + } else if (interpType == Backprojector::INTERP_CUBIC) { + double d = iDetCenter + dPos; // position along detector + if (d >= 0 && d < nDet) + pImCol[iy] += pCubicInterp->interpolate (d) / dL2; + } + } // end for y + } // end for x + + if (interpType == Backprojector::INTERP_CUBIC) + delete pCubicInterp; +} - if (iDetPos < 0 || iDetPos >= nDet) // check for impossible: index outside of raysum pos - errorIndexOutsideDetector (ix, iy, theta, curDetPos, iDetPos); - else - *pImCol++ += filteredProj[iDetPos]; +void +BackprojectEquilinear::BackprojectView (const double* const filteredProj, const double view_angle) +{ + double beta = view_angle; + + CubicPolyInterpolator* pCubicInterp = NULL; + if (interpType == Backprojector::INTERP_CUBIC) + pCubicInterp = new CubicPolyInterpolator (filteredProj, nDet); + + for (int ix = 0; ix < nx; ix++) { + ImageFileColumn pImCol = v[ix]; + + for (int iy = 0; iy < ny; iy++) { + double dAngleDiff = beta - phi[ix][iy]; + double rcos_t = r[ix][iy] * cos (dAngleDiff); + double rsin_t = r[ix][iy] * sin (dAngleDiff); + + double dU = (m_dFocalLength + rsin_t) / m_dFocalLength; + double dDetPos = rcos_t / dU; + // Scale for imaginary detector that passes through origin of phantom, see Kak-Slaney Figure 3.22. + dDetPos *= m_dSourceDetectorLength / m_dFocalLength; + double dPos = dDetPos / detInc; // position along detector array + + if (interpType == Backprojector::INTERP_NEAREST) { + int iDetPos = iDetCenter + nearest(dPos); // calc index in the filtered raysum vector + if (iDetPos >= 0 && iDetPos < nDet) + pImCol[iy] += (filteredProj[iDetPos] / (dU * dU)); } else if (interpType == Backprojector::INTERP_LINEAR) { - kint32 detPosFloor = curDetPos / scale; - kint32 detPosRemainder = curDetPos % scale; - if (detPosRemainder < 0) { - detPosFloor--; - detPosRemainder += scale; - } - int iDetPos = iDetCenter + detPosFloor; - double frac = detPosRemainder / dScale; - if (iDetPos < 0 || iDetPos >= nDet - 1) - errorIndexOutsideDetector (ix, iy, theta, curDetPos, iDetPos); - else - *pImCol++ += ((1-frac) * filteredProj[iDetPos] + frac * filteredProj[iDetPos+1]); + double dPosFloor = floor (dPos); + int iDetPos = iDetCenter + static_cast(dPosFloor); + double frac = dPos - dPosFloor; // fraction distance from det + if (iDetPos >= 0 && iDetPos < nDet - 1) + pImCol[iy] += (filteredProj[iDetPos] + frac * (filteredProj[iDetPos+1] - filteredProj[iDetPos])) + / (dU * dU); + } else if (interpType == Backprojector::INTERP_CUBIC) { + double d = iDetCenter + dPos; // position along detector + if (d >= 0 && d < nDet) + pImCol[iy] += pCubicInterp->interpolate (d) / (dU * dU); } - } // end for y - } // end for x + } // end for y + } // end for x + + if (interpType == Backprojector::INTERP_CUBIC) + delete pCubicInterp; } +