static int get_cell(DCELL *result, int fd, double x, double y) { static DCELL *row1, *row2; static int cur_row = -1; static int row, col; DCELL *tmp; if (!row1) { row1 = Rast_allocate_d_buf(); row2 = Rast_allocate_d_buf(); } col = (int)floor(x - 0.5); row = (int)floor(y - 0.5); x -= col + 0.5; y -= row + 0.5; if (row < 0 || row + 1 >= Rast_window_rows() || col < 0 || col + 1 >= Rast_window_cols()) { Rast_set_d_null_value(result, 1); return 0; } if (cur_row != row) { if (cur_row == row + 1) { tmp = row1; row1 = row2; row2 = tmp; Rast_get_d_row(fd, row1, row); } else if (cur_row == row - 1) { tmp = row1; row1 = row2; row2 = tmp; Rast_get_d_row(fd, row2, row + 1); } else { Rast_get_d_row(fd, row1, row); Rast_get_d_row(fd, row2, row + 1); } cur_row = row; } if (Rast_is_d_null_value(&row1[col]) || Rast_is_d_null_value(&row1[col+1]) || Rast_is_d_null_value(&row2[col]) || Rast_is_d_null_value(&row2[col+1])) { Rast_set_d_null_value(result, 1); return 0; } *result = Rast_interp_bilinear(x, y, row1[col], row1[col+1], row2[col], row2[col+1]); return 1; }
void p_bilinear(struct cache *ibuffer, /* input buffer */ void *obufptr, /* ptr in output buffer */ int cell_type, /* raster map type of obufptr */ double *row_idx, /* row index */ double *col_idx, /* column index */ struct Cell_head *cellhd /* information of output map */ ) { int row; /* row indices for interp */ int col; /* column indices for interp */ int i, j; DCELL t, u; /* intermediate slope */ DCELL result; /* result of interpolation */ DCELL c[2][2]; /* cut indices to integer */ row = (int)floor(*row_idx - 0.5); col = (int)floor(*col_idx - 0.5); /* check for out of bounds - if out of bounds set NULL value and return */ if (row < 0 || row + 1 >= cellhd->rows || col < 0 || col + 1 >= cellhd->cols) { Rast_set_null_value(obufptr, 1, cell_type); return; } for (i = 0; i < 2; i++) for (j = 0; j < 2; j++) { const DCELL *cellp = CPTR(ibuffer, row + i, col + j); if (Rast_is_d_null_value(cellp)) { Rast_set_null_value(obufptr, 1, cell_type); return; } c[i][j] = *cellp; } /* do the interpolation */ t = *col_idx - 0.5 - col; u = *row_idx - 0.5 - row; result = Rast_interp_bilinear(t, u, c[0][0], c[0][1], c[1][0], c[1][1]); Rast_set_d_value(obufptr, result, cell_type); }
/*! * \brief Extract a cell value from raster map (bilinear interpolation). * * Extract a cell value from raster map at given northing and easting * with a sampled 3x3 window using a bilinear interpolation. * * \param fd file descriptor * \param window region settings * \param cats categories * \param north northing position * \param east easting position * \param usedesc flag to scan category label * * \return cell value at given position */ DCELL Rast_get_sample_bilinear(int fd, const struct Cell_head * window, struct Categories * cats, double north, double east, int usedesc) { int row, col; double grid[2][2]; DCELL *arow = Rast_allocate_d_buf(); DCELL *brow = Rast_allocate_d_buf(); double frow, fcol, trow, tcol; DCELL result; frow = Rast_northing_to_row(north, window); fcol = Rast_easting_to_col(east, window); /* convert northing and easting to row and col, resp */ row = (int)floor(frow - 0.5); col = (int)floor(fcol - 0.5); trow = frow - row - 0.5; tcol = fcol - col - 0.5; if (row < 0 || row + 1 >= Rast_window_rows() || col < 0 || col + 1 >= Rast_window_cols()) { Rast_set_d_null_value(&result, 1); goto done; } Rast_get_d_row(fd, arow, row); Rast_get_d_row(fd, brow, row + 1); if (Rast_is_d_null_value(&arow[col]) || Rast_is_d_null_value(&arow[col + 1]) || Rast_is_d_null_value(&brow[col]) || Rast_is_d_null_value(&brow[col + 1])) { Rast_set_d_null_value(&result, 1); goto done; } /*- * now were ready to do bilinear interpolation over * arow[col], arow[col+1], * brow[col], brow[col+1] */ if (usedesc) { char *buf; G_squeeze(buf = Rast_get_c_cat((int *)&(arow[col]), cats)); grid[0][0] = scancatlabel(buf); G_squeeze(buf = Rast_get_c_cat((CELL *) & (arow[col + 1]), cats)); grid[0][1] = scancatlabel(buf); G_squeeze(buf = Rast_get_c_cat((CELL *) & (brow[col]), cats)); grid[1][0] = scancatlabel(buf); G_squeeze(buf = Rast_get_c_cat((CELL *) & (brow[col + 1]), cats)); grid[1][1] = scancatlabel(buf); } else { grid[0][0] = arow[col]; grid[0][1] = arow[col + 1]; grid[1][0] = brow[col]; grid[1][1] = brow[col + 1]; } result = Rast_interp_bilinear(tcol, trow, grid[0][0], grid[0][1], grid[1][0], grid[1][1]); done: G_free(arow); G_free(brow); return result; }
int main(int argc, char *argv[]) { struct GModule *module; struct Option *rastin, *rastout, *method; struct History history; char title[64]; char buf_nsres[100], buf_ewres[100]; struct Colors colors; int infile, outfile; DCELL *outbuf; int row, col; struct Cell_head dst_w, src_w; G_gisinit(argv[0]); module = G_define_module(); G_add_keyword(_("raster")); G_add_keyword(_("resample")); module->description = _("Resamples raster map layers to a finer grid using interpolation."); rastin = G_define_standard_option(G_OPT_R_INPUT); rastout = G_define_standard_option(G_OPT_R_OUTPUT); method = G_define_option(); method->key = "method"; method->type = TYPE_STRING; method->required = NO; method->description = _("Interpolation method"); method->options = "nearest,bilinear,bicubic,lanczos"; method->answer = "bilinear"; if (G_parser(argc, argv)) exit(EXIT_FAILURE); if (G_strcasecmp(method->answer, "nearest") == 0) neighbors = 1; else if (G_strcasecmp(method->answer, "bilinear") == 0) neighbors = 2; else if (G_strcasecmp(method->answer, "bicubic") == 0) neighbors = 4; else if (G_strcasecmp(method->answer, "lanczos") == 0) neighbors = 5; else G_fatal_error(_("Invalid method: %s"), method->answer); G_get_set_window(&dst_w); /* set window to old map */ Rast_get_cellhd(rastin->answer, "", &src_w); /* enlarge source window */ { double north = Rast_row_to_northing(0.5, &dst_w); double south = Rast_row_to_northing(dst_w.rows - 0.5, &dst_w); int r0 = (int)floor(Rast_northing_to_row(north, &src_w) - 0.5) - 2; int r1 = (int)floor(Rast_northing_to_row(south, &src_w) - 0.5) + 3; double west = Rast_col_to_easting(0.5, &dst_w); double east = Rast_col_to_easting(dst_w.cols - 0.5, &dst_w); int c0 = (int)floor(Rast_easting_to_col(west, &src_w) - 0.5) - 2; int c1 = (int)floor(Rast_easting_to_col(east, &src_w) - 0.5) + 3; src_w.south -= src_w.ns_res * (r1 - src_w.rows); src_w.north += src_w.ns_res * (-r0); src_w.west -= src_w.ew_res * (-c0); src_w.east += src_w.ew_res * (c1 - src_w.cols); src_w.rows = r1 - r0; src_w.cols = c1 - c0; } Rast_set_input_window(&src_w); /* allocate buffers for input rows */ for (row = 0; row < neighbors; row++) bufs[row] = Rast_allocate_d_input_buf(); cur_row = -100; /* open old map */ infile = Rast_open_old(rastin->answer, ""); /* reset window to current region */ Rast_set_output_window(&dst_w); outbuf = Rast_allocate_d_output_buf(); /* open new map */ outfile = Rast_open_new(rastout->answer, DCELL_TYPE); switch (neighbors) { case 1: /* nearest */ for (row = 0; row < dst_w.rows; row++) { double north = Rast_row_to_northing(row + 0.5, &dst_w); double maprow_f = Rast_northing_to_row(north, &src_w) - 0.5; int maprow0 = (int)floor(maprow_f + 0.5); G_percent(row, dst_w.rows, 2); read_rows(infile, maprow0); for (col = 0; col < dst_w.cols; col++) { double east = Rast_col_to_easting(col + 0.5, &dst_w); double mapcol_f = Rast_easting_to_col(east, &src_w) - 0.5; int mapcol0 = (int)floor(mapcol_f + 0.5); double c = bufs[0][mapcol0]; if (Rast_is_d_null_value(&c)) { Rast_set_d_null_value(&outbuf[col], 1); } else { outbuf[col] = c; } } Rast_put_d_row(outfile, outbuf); } break; case 2: /* bilinear */ for (row = 0; row < dst_w.rows; row++) { double north = Rast_row_to_northing(row + 0.5, &dst_w); double maprow_f = Rast_northing_to_row(north, &src_w) - 0.5; int maprow0 = (int)floor(maprow_f); double v = maprow_f - maprow0; G_percent(row, dst_w.rows, 2); read_rows(infile, maprow0); for (col = 0; col < dst_w.cols; col++) { double east = Rast_col_to_easting(col + 0.5, &dst_w); double mapcol_f = Rast_easting_to_col(east, &src_w) - 0.5; int mapcol0 = (int)floor(mapcol_f); int mapcol1 = mapcol0 + 1; double u = mapcol_f - mapcol0; double c00 = bufs[0][mapcol0]; double c01 = bufs[0][mapcol1]; double c10 = bufs[1][mapcol0]; double c11 = bufs[1][mapcol1]; if (Rast_is_d_null_value(&c00) || Rast_is_d_null_value(&c01) || Rast_is_d_null_value(&c10) || Rast_is_d_null_value(&c11)) { Rast_set_d_null_value(&outbuf[col], 1); } else { outbuf[col] = Rast_interp_bilinear(u, v, c00, c01, c10, c11); } } Rast_put_d_row(outfile, outbuf); } break; case 4: /* bicubic */ for (row = 0; row < dst_w.rows; row++) { double north = Rast_row_to_northing(row + 0.5, &dst_w); double maprow_f = Rast_northing_to_row(north, &src_w) - 0.5; int maprow1 = (int)floor(maprow_f); int maprow0 = maprow1 - 1; double v = maprow_f - maprow1; G_percent(row, dst_w.rows, 2); read_rows(infile, maprow0); for (col = 0; col < dst_w.cols; col++) { double east = Rast_col_to_easting(col + 0.5, &dst_w); double mapcol_f = Rast_easting_to_col(east, &src_w) - 0.5; int mapcol1 = (int)floor(mapcol_f); int mapcol0 = mapcol1 - 1; int mapcol2 = mapcol1 + 1; int mapcol3 = mapcol1 + 2; double u = mapcol_f - mapcol1; double c00 = bufs[0][mapcol0]; double c01 = bufs[0][mapcol1]; double c02 = bufs[0][mapcol2]; double c03 = bufs[0][mapcol3]; double c10 = bufs[1][mapcol0]; double c11 = bufs[1][mapcol1]; double c12 = bufs[1][mapcol2]; double c13 = bufs[1][mapcol3]; double c20 = bufs[2][mapcol0]; double c21 = bufs[2][mapcol1]; double c22 = bufs[2][mapcol2]; double c23 = bufs[2][mapcol3]; double c30 = bufs[3][mapcol0]; double c31 = bufs[3][mapcol1]; double c32 = bufs[3][mapcol2]; double c33 = bufs[3][mapcol3]; if (Rast_is_d_null_value(&c00) || Rast_is_d_null_value(&c01) || Rast_is_d_null_value(&c02) || Rast_is_d_null_value(&c03) || Rast_is_d_null_value(&c10) || Rast_is_d_null_value(&c11) || Rast_is_d_null_value(&c12) || Rast_is_d_null_value(&c13) || Rast_is_d_null_value(&c20) || Rast_is_d_null_value(&c21) || Rast_is_d_null_value(&c22) || Rast_is_d_null_value(&c23) || Rast_is_d_null_value(&c30) || Rast_is_d_null_value(&c31) || Rast_is_d_null_value(&c32) || Rast_is_d_null_value(&c33)) { Rast_set_d_null_value(&outbuf[col], 1); } else { outbuf[col] = Rast_interp_bicubic(u, v, c00, c01, c02, c03, c10, c11, c12, c13, c20, c21, c22, c23, c30, c31, c32, c33); } } Rast_put_d_row(outfile, outbuf); } break; case 5: /* lanczos */ for (row = 0; row < dst_w.rows; row++) { double north = Rast_row_to_northing(row + 0.5, &dst_w); double maprow_f = Rast_northing_to_row(north, &src_w) - 0.5; int maprow1 = (int)floor(maprow_f + 0.5); int maprow0 = maprow1 - 2; double v = maprow_f - maprow1; G_percent(row, dst_w.rows, 2); read_rows(infile, maprow0); for (col = 0; col < dst_w.cols; col++) { double east = Rast_col_to_easting(col + 0.5, &dst_w); double mapcol_f = Rast_easting_to_col(east, &src_w) - 0.5; int mapcol2 = (int)floor(mapcol_f + 0.5); int mapcol0 = mapcol2 - 2; int mapcol4 = mapcol2 + 2; double u = mapcol_f - mapcol2; double c[25]; int ci = 0, i, j, do_lanczos = 1; for (i = 0; i < 5; i++) { for (j = mapcol0; j <= mapcol4; j++) { c[ci] = bufs[i][j]; if (Rast_is_d_null_value(&(c[ci]))) { Rast_set_d_null_value(&outbuf[col], 1); do_lanczos = 0; break; } ci++; } if (!do_lanczos) break; } if (do_lanczos) { outbuf[col] = Rast_interp_lanczos(u, v, c); } } Rast_put_d_row(outfile, outbuf); } break; } G_percent(dst_w.rows, dst_w.rows, 2); Rast_close(infile); Rast_close(outfile); /* record map metadata/history info */ sprintf(title, "Resample by %s interpolation", method->answer); Rast_put_cell_title(rastout->answer, title); Rast_short_history(rastout->answer, "raster", &history); Rast_set_history(&history, HIST_DATSRC_1, rastin->answer); G_format_resolution(src_w.ns_res, buf_nsres, src_w.proj); G_format_resolution(src_w.ew_res, buf_ewres, src_w.proj); Rast_format_history(&history, HIST_DATSRC_2, "Source map NS res: %s EW res: %s", buf_nsres, buf_ewres); Rast_command_history(&history); Rast_write_history(rastout->answer, &history); /* copy color table from source map */ if (Rast_read_colors(rastin->answer, "", &colors) < 0) G_fatal_error(_("Unable to read color table for %s"), rastin->answer); Rast_mark_colors_as_fp(&colors); Rast_write_colors(rastout->answer, G_mapset(), &colors); return (EXIT_SUCCESS); }