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Diffstat (limited to 'plugins/FreeImage/src/FreeImageToolkit/MultigridPoissonSolver.cpp')
| -rw-r--r-- | plugins/FreeImage/src/FreeImageToolkit/MultigridPoissonSolver.cpp | 505 |
1 files changed, 0 insertions, 505 deletions
diff --git a/plugins/FreeImage/src/FreeImageToolkit/MultigridPoissonSolver.cpp b/plugins/FreeImage/src/FreeImageToolkit/MultigridPoissonSolver.cpp deleted file mode 100644 index a31961447a..0000000000 --- a/plugins/FreeImage/src/FreeImageToolkit/MultigridPoissonSolver.cpp +++ /dev/null @@ -1,505 +0,0 @@ -// ========================================================== -// Poisson solver based on a full multigrid algorithm -// -// Design and implementation by -// - Hervé Drolon (drolon@infonie.fr) -// Reference: -// PRESS, W. H., TEUKOLSKY, S. A., VETTERLING, W. T., AND FLANNERY, B. P. -// 1992. Numerical Recipes in C: The Art of Scientific Computing, 2nd ed. Cambridge University Press. -// -// This file is part of FreeImage 3 -// -// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY -// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES -// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE -// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED -// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT -// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY -// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL -// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER -// THIS DISCLAIMER. -// -// Use at your own risk! -// ========================================================== - -#include "FreeImage.h" -#include "Utilities.h" -#include "ToneMapping.h" - -static const int NPRE = 1; // Number of relaxation sweeps before ... -static const int NPOST = 1; // ... and after the coarse-grid correction is computed -static const int NGMAX = 15; // Maximum number of grids - -/** -Copy src into dst -*/ -static inline void fmg_copyArray(FIBITMAP *dst, FIBITMAP *src) { - memcpy(FreeImage_GetBits(dst), FreeImage_GetBits(src), FreeImage_GetHeight(dst) * FreeImage_GetPitch(dst)); -} - -/** -Fills src with zeros -*/ -static inline void fmg_fillArrayWithZeros(FIBITMAP *src) { - memset(FreeImage_GetBits(src), 0, FreeImage_GetHeight(src) * FreeImage_GetPitch(src)); -} - -/** -Half-weighting restriction. nc is the coarse-grid dimension. The fine-grid solution is input in -uf[0..2*nc-2][0..2*nc-2], the coarse-grid solution is returned in uc[0..nc-1][0..nc-1]. -*/ -static void fmg_restrict(FIBITMAP *UC, FIBITMAP *UF, int nc) { - int row_uc, row_uf, col_uc, col_uf; - - const int uc_pitch = FreeImage_GetPitch(UC) / sizeof(float); - const int uf_pitch = FreeImage_GetPitch(UF) / sizeof(float); - - float *uc_bits = (float*)FreeImage_GetBits(UC); - const float *uf_bits = (float*)FreeImage_GetBits(UF); - - // interior points - { - float *uc_scan = uc_bits + uc_pitch; - for (row_uc = 1, row_uf = 2; row_uc < nc-1; row_uc++, row_uf += 2) { - const float *uf_scan = uf_bits + row_uf * uf_pitch; - for (col_uc = 1, col_uf = 2; col_uc < nc-1; col_uc++, col_uf += 2) { - // calculate - // UC(row_uc, col_uc) = - // 0.5 * UF(row_uf, col_uf) + 0.125 * [ UF(row_uf+1, col_uf) + UF(row_uf-1, col_uf) + UF(row_uf, col_uf+1) + UF(row_uf, col_uf-1) ] - float *uc_pixel = uc_scan + col_uc; - const float *uf_center = uf_scan + col_uf; - *uc_pixel = 0.5F * *uf_center + 0.125F * ( *(uf_center + uf_pitch) + *(uf_center - uf_pitch) + *(uf_center + 1) + *(uf_center - 1)); - } - uc_scan += uc_pitch; - } - } - // boundary points - const int ncc = 2*nc-1; - { - /* - calculate the following: - for (row_uc = 0, row_uf = 0; row_uc < nc; row_uc++, row_uf += 2) { - UC(row_uc, 0) = UF(row_uf, 0); - UC(row_uc, nc-1) = UF(row_uf, ncc-1); - } - */ - float *uc_scan = uc_bits; - for (row_uc = 0, row_uf = 0; row_uc < nc; row_uc++, row_uf += 2) { - const float *uf_scan = uf_bits + row_uf * uf_pitch; - uc_scan[0] = uf_scan[0]; - uc_scan[nc-1] = uf_scan[ncc-1]; - uc_scan += uc_pitch; - } - } - { - /* - calculate the following: - for (col_uc = 0, col_uf = 0; col_uc < nc; col_uc++, col_uf += 2) { - UC(0, col_uc) = UF(0, col_uf); - UC(nc-1, col_uc) = UF(ncc-1, col_uf); - } - */ - float *uc_scan_top = uc_bits; - float *uc_scan_bottom = uc_bits + (nc-1)*uc_pitch; - const float *uf_scan_top = uf_bits + (ncc-1)*uf_pitch; - const float *uf_scan_bottom = uf_bits; - for (col_uc = 0, col_uf = 0; col_uc < nc; col_uc++, col_uf += 2) { - uc_scan_top[col_uc] = uf_scan_top[col_uf]; - uc_scan_bottom[col_uc] = uf_scan_bottom[col_uf]; - } - } -} - -/** -Solution of the model problem on the coarsest grid, where h = 1/2 . -The right-hand side is input -in rhs[0..2][0..2] and the solution is returned in u[0..2][0..2]. -*/ -static void fmg_solve(FIBITMAP *U, FIBITMAP *RHS) { - // fill U with zeros - fmg_fillArrayWithZeros(U); - // calculate U(1, 1) = -h*h*RHS(1, 1)/4.0 where h = 1/2 - float *u_scan = (float*)FreeImage_GetScanLine(U, 1); - const float *rhs_scan = (float*)FreeImage_GetScanLine(RHS, 1); - u_scan[1] = -rhs_scan[1] / 16; -} - -/** -Coarse-to-fine prolongation by bilinear interpolation. nf is the fine-grid dimension. The coarsegrid -solution is input as uc[0..nc-1][0..nc-1], where nc = nf/2 + 1. The fine-grid solution is -returned in uf[0..nf-1][0..nf-1]. -*/ -static void fmg_prolongate(FIBITMAP *UF, FIBITMAP *UC, int nf) { - int row_uc, row_uf, col_uc, col_uf; - - const int uf_pitch = FreeImage_GetPitch(UF) / sizeof(float); - const int uc_pitch = FreeImage_GetPitch(UC) / sizeof(float); - - float *uf_bits = (float*)FreeImage_GetBits(UF); - const float *uc_bits = (float*)FreeImage_GetBits(UC); - - // do elements that are copies - { - const int nc = nf/2 + 1; - - float *uf_scan = uf_bits; - const float *uc_scan = uc_bits; - for (row_uc = 0; row_uc < nc; row_uc++) { - for (col_uc = 0, col_uf = 0; col_uc < nc; col_uc++, col_uf += 2) { - // calculate UF(2*row_uc, col_uf) = UC(row_uc, col_uc); - uf_scan[col_uf] = uc_scan[col_uc]; - } - uc_scan += uc_pitch; - uf_scan += 2 * uf_pitch; - } - } - // do odd-numbered columns, interpolating vertically - { - for(row_uf = 1; row_uf < nf-1; row_uf += 2) { - float *uf_scan = uf_bits + row_uf * uf_pitch; - for (col_uf = 0; col_uf < nf; col_uf += 2) { - // calculate UF(row_uf, col_uf) = 0.5 * ( UF(row_uf+1, col_uf) + UF(row_uf-1, col_uf)) - uf_scan[col_uf] = 0.5F * ( *(uf_scan + uf_pitch + col_uf) + *(uf_scan - uf_pitch + col_uf)); - } - } - } - // do even-numbered columns, interpolating horizontally - { - float *uf_scan = uf_bits; - for(row_uf = 0; row_uf < nf; row_uf++) { - for (col_uf = 1; col_uf < nf-1; col_uf += 2) { - // calculate UF(row_uf, col_uf) = 0.5 * ( UF(row_uf, col_uf+1) + UF(row_uf, col_uf-1)) - uf_scan[col_uf] = 0.5F * ( uf_scan[col_uf + 1] + uf_scan[col_uf - 1] ); - } - uf_scan += uf_pitch; - } - } -} - -/** -Red-black Gauss-Seidel relaxation for model problem. Updates the current value of the solution -u[0..n-1][0..n-1], using the right-hand side function rhs[0..n-1][0..n-1]. -*/ -static void fmg_relaxation(FIBITMAP *U, FIBITMAP *RHS, int n) { - int row, col, ipass, isw, jsw; - const float h = 1.0F / (n - 1); - const float h2 = h*h; - - const int u_pitch = FreeImage_GetPitch(U) / sizeof(float); - const int rhs_pitch = FreeImage_GetPitch(RHS) / sizeof(float); - - float *u_bits = (float*)FreeImage_GetBits(U); - const float *rhs_bits = (float*)FreeImage_GetBits(RHS); - - for (ipass = 0, jsw = 1; ipass < 2; ipass++, jsw = 3-jsw) { // Red and black sweeps - float *u_scan = u_bits + u_pitch; - const float *rhs_scan = rhs_bits + rhs_pitch; - for (row = 1, isw = jsw; row < n-1; row++, isw = 3-isw) { - for (col = isw; col < n-1; col += 2) { - // Gauss-Seidel formula - // calculate U(row, col) = - // 0.25 * [ U(row+1, col) + U(row-1, col) + U(row, col+1) + U(row, col-1) - h2 * RHS(row, col) ] - float *u_center = u_scan + col; - const float *rhs_center = rhs_scan + col; - *u_center = *(u_center + u_pitch) + *(u_center - u_pitch) + *(u_center + 1) + *(u_center - 1); - *u_center -= h2 * *rhs_center; - *u_center *= 0.25F; - } - u_scan += u_pitch; - rhs_scan += rhs_pitch; - } - } -} - -/** -Returns minus the residual for the model problem. Input quantities are u[0..n-1][0..n-1] and -rhs[0..n-1][0..n-1], while res[0..n-1][0..n-1] is returned. -*/ -static void fmg_residual(FIBITMAP *RES, FIBITMAP *U, FIBITMAP *RHS, int n) { - int row, col; - - const float h = 1.0F / (n-1); - const float h2i = 1.0F / (h*h); - - const int res_pitch = FreeImage_GetPitch(RES) / sizeof(float); - const int u_pitch = FreeImage_GetPitch(U) / sizeof(float); - const int rhs_pitch = FreeImage_GetPitch(RHS) / sizeof(float); - - float *res_bits = (float*)FreeImage_GetBits(RES); - const float *u_bits = (float*)FreeImage_GetBits(U); - const float *rhs_bits = (float*)FreeImage_GetBits(RHS); - - // interior points - { - float *res_scan = res_bits + res_pitch; - const float *u_scan = u_bits + u_pitch; - const float *rhs_scan = rhs_bits + rhs_pitch; - for (row = 1; row < n-1; row++) { - for (col = 1; col < n-1; col++) { - // calculate RES(row, col) = - // -h2i * [ U(row+1, col) + U(row-1, col) + U(row, col+1) + U(row, col-1) - 4 * U(row, col) ] + RHS(row, col); - float *res_center = res_scan + col; - const float *u_center = u_scan + col; - const float *rhs_center = rhs_scan + col; - *res_center = *(u_center + u_pitch) + *(u_center - u_pitch) + *(u_center + 1) + *(u_center - 1) - 4 * *u_center; - *res_center *= -h2i; - *res_center += *rhs_center; - } - res_scan += res_pitch; - u_scan += u_pitch; - rhs_scan += rhs_pitch; - } - } - - // boundary points - { - memset(FreeImage_GetScanLine(RES, 0), 0, FreeImage_GetPitch(RES)); - memset(FreeImage_GetScanLine(RES, n-1), 0, FreeImage_GetPitch(RES)); - float *left = res_bits; - float *right = res_bits + (n-1); - for(int k = 0; k < n; k++) { - *left = 0; - *right = 0; - left += res_pitch; - right += res_pitch; - } - } -} - -/** -Does coarse-to-fine interpolation and adds result to uf. nf is the fine-grid dimension. The -coarse-grid solution is input as uc[0..nc-1][0..nc-1], where nc = nf/2+1. The fine-grid solution -is returned in uf[0..nf-1][0..nf-1]. res[0..nf-1][0..nf-1] is used for temporary storage. -*/ -static void fmg_addint(FIBITMAP *UF, FIBITMAP *UC, FIBITMAP *RES, int nf) { - fmg_prolongate(RES, UC, nf); - - const int uf_pitch = FreeImage_GetPitch(UF) / sizeof(float); - const int res_pitch = FreeImage_GetPitch(RES) / sizeof(float); - - float *uf_bits = (float*)FreeImage_GetBits(UF); - const float *res_bits = (float*)FreeImage_GetBits(RES); - - for(int row = 0; row < nf; row++) { - for(int col = 0; col < nf; col++) { - // calculate UF(row, col) = UF(row, col) + RES(row, col); - uf_bits[col] += res_bits[col]; - } - uf_bits += uf_pitch; - res_bits += res_pitch; - } -} - -/** -Full Multigrid Algorithm for solution of linear elliptic equation, here the model problem (19.0.6). -On input u[0..n-1][0..n-1] contains the right-hand side ñ, while on output it returns the solution. -The dimension n must be of the form 2^j + 1 for some integer j. (j is actually the number of -grid levels used in the solution, called ng below.) ncycle is the number of V-cycles to be -used at each level. -*/ -static BOOL fmg_mglin(FIBITMAP *U, int n, int ncycle) { - int j, jcycle, jj, jpost, jpre, nf, ngrid; - - FIBITMAP **IRHO = NULL; - FIBITMAP **IU = NULL; - FIBITMAP **IRHS = NULL; - FIBITMAP **IRES = NULL; - - int ng = 0; // number of allocated grids - -// -------------------------------------------------------------------------- - -#define _CREATE_ARRAY_GRID_(array, array_size) \ - array = (FIBITMAP**)malloc(array_size * sizeof(FIBITMAP*));\ - if (!array) throw(1);\ - memset(array, 0, array_size * sizeof(FIBITMAP*)) - -#define _FREE_ARRAY_GRID_(array, array_size) \ - if(NULL != array) {\ - for(int k = 0; k < array_size; k++) {\ - if(NULL != array[k]) {\ - FreeImage_Unload(array[k]); array[k] = NULL;\ - }\ - }\ - free(array);\ - } - -// -------------------------------------------------------------------------- - - try { - int nn = n; - // check grid size and grid levels - while (nn >>= 1) ng++; - if (n != 1 + (1L << ng)) { - FreeImage_OutputMessageProc(FIF_UNKNOWN, "Multigrid algorithm: n = %d, while n-1 must be a power of 2.", n); - throw(1); - } - if (ng > NGMAX) { - FreeImage_OutputMessageProc(FIF_UNKNOWN, "Multigrid algorithm: ng = %d while NGMAX = %d, increase NGMAX.", ng, NGMAX); - throw(1); - } - // allocate grid arrays - { - _CREATE_ARRAY_GRID_(IRHO, ng); - _CREATE_ARRAY_GRID_(IU, ng); - _CREATE_ARRAY_GRID_(IRHS, ng); - _CREATE_ARRAY_GRID_(IRES, ng); - } - - nn = n/2 + 1; - ngrid = ng - 2; - - // allocate storage for r.h.s. on grid (ng - 2) ... - IRHO[ngrid] = FreeImage_AllocateT(FIT_FLOAT, nn, nn); - if (!IRHO[ngrid]) throw(1); - - // ... and fill it by restricting from the fine grid - fmg_restrict(IRHO[ngrid], U, nn); - - // similarly allocate storage and fill r.h.s. on all coarse grids. - while (nn > 3) { - nn = nn/2 + 1; - ngrid--; - IRHO[ngrid] = FreeImage_AllocateT(FIT_FLOAT, nn, nn); - if (!IRHO[ngrid]) throw(1); - fmg_restrict(IRHO[ngrid], IRHO[ngrid+1], nn); - } - - nn = 3; - - IU[0] = FreeImage_AllocateT(FIT_FLOAT, nn, nn); - if (!IU[0]) throw(1); - IRHS[0] = FreeImage_AllocateT(FIT_FLOAT, nn, nn); - if (!IRHS[0]) throw(1); - - // initial solution on coarsest grid - fmg_solve(IU[0], IRHO[0]); - // irho[0] no longer needed ... - FreeImage_Unload(IRHO[0]); IRHO[0] = NULL; - - ngrid = ng; - - // nested iteration loop - for (j = 1; j < ngrid; j++) { - nn = 2*nn - 1; - - IU[j] = FreeImage_AllocateT(FIT_FLOAT, nn, nn); - if (!IU[j]) throw(1); - IRHS[j] = FreeImage_AllocateT(FIT_FLOAT, nn, nn); - if (!IRHS[j]) throw(1); - IRES[j] = FreeImage_AllocateT(FIT_FLOAT, nn, nn); - if (!IRES[j]) throw(1); - - fmg_prolongate(IU[j], IU[j-1], nn); - - // interpolate from coarse grid to next finer grid - - // set up r.h.s. - fmg_copyArray(IRHS[j], j != (ngrid - 1) ? IRHO[j] : U); - - // V-cycle loop - for (jcycle = 0; jcycle < ncycle; jcycle++) { - nf = nn; - // downward stoke of the V - for (jj = j; jj >= 1; jj--) { - // pre-smoothing - for (jpre = 0; jpre < NPRE; jpre++) { - fmg_relaxation(IU[jj], IRHS[jj], nf); - } - fmg_residual(IRES[jj], IU[jj], IRHS[jj], nf); - nf = nf/2 + 1; - // restriction of the residual is the next r.h.s. - fmg_restrict(IRHS[jj-1], IRES[jj], nf); - // zero for initial guess in next relaxation - fmg_fillArrayWithZeros(IU[jj-1]); - } - // bottom of V: solve on coarsest grid - fmg_solve(IU[0], IRHS[0]); - nf = 3; - // upward stroke of V. - for (jj = 1; jj <= j; jj++) { - nf = 2*nf - 1; - // use res for temporary storage inside addint - fmg_addint(IU[jj], IU[jj-1], IRES[jj], nf); - // post-smoothing - for (jpost = 0; jpost < NPOST; jpost++) { - fmg_relaxation(IU[jj], IRHS[jj], nf); - } - } - } - } - - // return solution in U - fmg_copyArray(U, IU[ngrid-1]); - - // delete allocated arrays - _FREE_ARRAY_GRID_(IRES, ng); - _FREE_ARRAY_GRID_(IRHS, ng); - _FREE_ARRAY_GRID_(IU, ng); - _FREE_ARRAY_GRID_(IRHO, ng); - - return TRUE; - - } catch(int) { - // delete allocated arrays - _FREE_ARRAY_GRID_(IRES, ng); - _FREE_ARRAY_GRID_(IRHS, ng); - _FREE_ARRAY_GRID_(IU, ng); - _FREE_ARRAY_GRID_(IRHO, ng); - - return FALSE; - } -} - -// -------------------------------------------------------------------------- - -/** -Poisson solver based on a multigrid algorithm. -This routine solves a Poisson equation, remap result pixels to [0..1] and returns the solution. -NB: The input image is first stored inside a square image whose size is (2^j + 1)x(2^j + 1) for some integer j, -where j is such that 2^j is the nearest larger dimension corresponding to MAX(image width, image height). -@param Laplacian Laplacian image -@param ncycle Number of cycles in the multigrid algorithm (usually 2 or 3) -@return Returns the solved PDE equations if successful, returns NULL otherwise -*/ -FIBITMAP* DLL_CALLCONV -FreeImage_MultigridPoissonSolver(FIBITMAP *Laplacian, int ncycle) { - if (!FreeImage_HasPixels(Laplacian)) return NULL; - - int width = FreeImage_GetWidth(Laplacian); - int height = FreeImage_GetHeight(Laplacian); - - // get nearest larger dimension length that is acceptable by the algorithm - int n = MAX(width, height); - int size = 0; - while((n >>= 1) > 0) size++; - if ((1 << size) < MAX(width, height)) { - size++; - } - // size must be of the form 2^j + 1 for some integer j - size = 1 + (1 << size); - - // allocate a temporary square image I - FIBITMAP *I = FreeImage_AllocateT(FIT_FLOAT, size, size); - if (!I) return NULL; - - // copy Laplacian into I and shift pixels to create a boundary - FreeImage_Paste(I, Laplacian, 1, 1, 255); - - // solve the PDE equation - fmg_mglin(I, size, ncycle); - - // shift pixels back - FIBITMAP *U = FreeImage_Copy(I, 1, 1, width + 1, height + 1); - FreeImage_Unload(I); - - // remap pixels to [0..1] - NormalizeY(U, 0, 1); - - // copy metadata from src to dst - FreeImage_CloneMetadata(U, Laplacian); - - // return the integrated image - return U; -} - |