From 4ed227cf0ec915f781e5f8a51e21f9150a6b7139 Mon Sep 17 00:00:00 2001 From: Sven Neumann Date: Wed, 18 Jul 2007 12:47:00 +0000 Subject: [PATCH] app/paint-funcs/Makefile.am app/paint-funcs/scale-funcs.[ch] moved 2007-07-17 Sven Neumann * app/paint-funcs/Makefile.am * app/paint-funcs/scale-funcs.[ch] * app/paint-funcs/sample-funcs.[ch]: moved subsample_region() to new file and also moved subsample_indexed_region() there. * app/base/tile-manager-preview.c * app/core/gimpdrawable-preview.c: changed accordingly. svn path=/trunk/; revision=22953 --- ChangeLog | 10 + app/base/tile-manager-preview.c | 2 +- app/core/gimpdrawable-preview.c | 222 +---------------- app/paint-funcs/Makefile.am | 4 +- app/paint-funcs/sample-funcs.c | 411 ++++++++++++++++++++++++++++++++ app/paint-funcs/sample-funcs.h | 33 +++ app/paint-funcs/scale-funcs.c | 164 ------------- app/paint-funcs/scale-funcs.h | 25 +- 8 files changed, 472 insertions(+), 399 deletions(-) create mode 100644 app/paint-funcs/sample-funcs.c create mode 100644 app/paint-funcs/sample-funcs.h diff --git a/ChangeLog b/ChangeLog index 61660f3c8b..24f9d4d46d 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2007-07-17 Sven Neumann + + * app/paint-funcs/Makefile.am + * app/paint-funcs/scale-funcs.[ch] + * app/paint-funcs/sample-funcs.[ch]: moved subsample_region() to + new file and also moved subsample_indexed_region() there. + + * app/base/tile-manager-preview.c + * app/core/gimpdrawable-preview.c: changed accordingly. + 2007-07-17 Raphaël Quinet * plug-ins/jpeg/jpeg.c diff --git a/app/base/tile-manager-preview.c b/app/base/tile-manager-preview.c index 016a7bdb9c..df403ba1e1 100644 --- a/app/base/tile-manager-preview.c +++ b/app/base/tile-manager-preview.c @@ -22,7 +22,7 @@ #include "base-types.h" -#include "paint-funcs/scale-funcs.h" +#include "paint-funcs/sample-funcs.h" #include "pixel-region.h" #include "temp-buf.h" diff --git a/app/core/gimpdrawable-preview.c b/app/core/gimpdrawable-preview.c index 4fa3754857..e303da7134 100644 --- a/app/core/gimpdrawable-preview.c +++ b/app/core/gimpdrawable-preview.c @@ -30,7 +30,7 @@ #include "base/temp-buf.h" #include "base/tile-manager-preview.h" -#include "paint-funcs/scale-funcs.h" +#include "paint-funcs/sample-funcs.h" #include "config/gimpcoreconfig.h" @@ -57,11 +57,6 @@ static TempBuf * gimp_drawable_indexed_preview (GimpDrawable *drawable, gint dest_width, gint dest_height); -static void subsample_indexed_region (PixelRegion *srcPR, - PixelRegion *destPR, - const guchar *cmap, - gint subsample); - /* public functions */ @@ -236,218 +231,3 @@ gimp_drawable_indexed_preview (GimpDrawable *drawable, return preview_buf; } - -static void -subsample_indexed_region (PixelRegion *srcPR, - PixelRegion *destPR, - const guchar *cmap, - gint subsample) -{ -#define EPSILON 0.000001 - guchar *src, *s; - guchar *dest, *d; - gdouble *row, *r; - gint destwidth; - gint src_row, src_col; - gint bytes, b; - gint width, height; - gint orig_width, orig_height; - gdouble x_rat, y_rat; - gdouble x_cum, y_cum; - gdouble x_last, y_last; - gdouble *x_frac, y_frac, tot_frac; - gint i, j; - gint frac; - gboolean advance_dest; - gboolean has_alpha; - - g_return_if_fail (cmap != NULL); - - orig_width = srcPR->w / subsample; - orig_height = srcPR->h / subsample; - width = destPR->w; - height = destPR->h; - - /* Some calculations... */ - bytes = destPR->bytes; - destwidth = destPR->rowstride; - - has_alpha = pixel_region_has_alpha (srcPR); - - /* the data pointers... */ - src = g_new (guchar, orig_width * bytes); - dest = destPR->data; - - /* find the ratios of old x to new x and old y to new y */ - x_rat = (gdouble) orig_width / (gdouble) width; - y_rat = (gdouble) orig_height / (gdouble) height; - - /* allocate an array to help with the calculations */ - row = g_new0 (gdouble, width * bytes); - x_frac = g_new (gdouble, width + orig_width); - - /* initialize the pre-calculated pixel fraction array */ - src_col = 0; - x_cum = (gdouble) src_col; - x_last = x_cum; - - for (i = 0; i < width + orig_width; i++) - { - if (x_cum + x_rat <= (src_col + 1 + EPSILON)) - { - x_cum += x_rat; - x_frac[i] = x_cum - x_last; - } - else - { - src_col++; - x_frac[i] = src_col - x_last; - } - - x_last += x_frac[i]; - } - - /* counters... */ - src_row = 0; - y_cum = (gdouble) src_row; - y_last = y_cum; - - pixel_region_get_row (srcPR, - srcPR->x, - srcPR->y + src_row * subsample, - orig_width * subsample, - src, - subsample); - - /* Scale the selected region */ - for (i = 0; i < height; ) - { - src_col = 0; - x_cum = (gdouble) src_col; - - /* determine the fraction of the src pixel we are using for y */ - if (y_cum + y_rat <= (src_row + 1 + EPSILON)) - { - y_cum += y_rat; - y_frac = y_cum - y_last; - advance_dest = TRUE; - } - else - { - src_row++; - y_frac = src_row - y_last; - advance_dest = FALSE; - } - - y_last += y_frac; - - s = src; - r = row; - - frac = 0; - - j = width; - while (j) - { - gint index = *s * 3; - - tot_frac = x_frac[frac++] * y_frac; - - /* transform the color to RGB */ - if (has_alpha) - { - if (s[ALPHA_I_PIX] & 0x80) - { - r[RED_PIX] += cmap[index++] * tot_frac; - r[GREEN_PIX] += cmap[index++] * tot_frac; - r[BLUE_PIX] += cmap[index++] * tot_frac; - r[ALPHA_PIX] += tot_frac; - } - /* else the pixel contributes nothing and needs not to be added - */ - } - else - { - r[RED_PIX] += cmap[index++] * tot_frac; - r[GREEN_PIX] += cmap[index++] * tot_frac; - r[BLUE_PIX] += cmap[index++] * tot_frac; - } - - /* increment the destination */ - if (x_cum + x_rat <= (src_col + 1 + EPSILON)) - { - r += bytes; - x_cum += x_rat; - j--; - } - /* increment the source */ - else - { - s += srcPR->bytes; - src_col++; - } - } - - if (advance_dest) - { - tot_frac = 1.0 / (x_rat * y_rat); - - /* copy "row" to "dest" */ - d = dest; - r = row; - - j = width; - while (j--) - { - if (has_alpha) - { - /* unpremultiply */ - - gdouble alpha = r[bytes - 1]; - - if (alpha > EPSILON) - { - for (b = 0; b < (bytes - 1); b++) - d[b] = (guchar) ((r[b] / alpha) + 0.5); - - d[bytes - 1] = (guchar) ((alpha * tot_frac * 255.0) + 0.5); - } - else - { - for (b = 0; b < bytes; b++) - d[b] = 0; - } - } - else - { - for (b = 0; b < bytes; b++) - d[b] = (guchar) ((r[b] * tot_frac) + 0.5); - } - - r += bytes; - d += bytes; - } - - dest += destwidth; - - /* clear the "row" array */ - memset (row, 0, sizeof (gdouble) * destwidth); - - i++; - } - else - { - pixel_region_get_row (srcPR, - srcPR->x, - srcPR->y + src_row * subsample, - orig_width * subsample, - src, - subsample); - } - } - - /* free up temporary arrays */ - g_free (row); - g_free (x_frac); - g_free (src); -} diff --git a/app/paint-funcs/Makefile.am b/app/paint-funcs/Makefile.am index 7bd8d6cd69..a4b58beba1 100644 --- a/app/paint-funcs/Makefile.am +++ b/app/paint-funcs/Makefile.am @@ -6,7 +6,9 @@ libapppaint_funcs_a_SOURCES = \ paint-funcs-types.h \ paint-funcs.c \ paint-funcs.h \ - paint-funcs-generic.h \ + paint-funcs-generic.h \ + sample-funcs.c \ + sample-funcs.h \ scale-funcs.c \ scale-funcs.h diff --git a/app/paint-funcs/sample-funcs.c b/app/paint-funcs/sample-funcs.c new file mode 100644 index 0000000000..ca2b077655 --- /dev/null +++ b/app/paint-funcs/sample-funcs.c @@ -0,0 +1,411 @@ +/* GIMP - The GNU Image Manipulation Program + * Copyright (C) 1995 Spencer Kimball and Peter Mattis + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include "config.h" + +#include + +#include + +#include "paint-funcs-types.h" + +#include "base/pixel-region.h" + +#include "sample-funcs.h" + + +#define EPSILON (0.0001) /* arbitary small number for avoiding zero */ + + +void +subsample_region (PixelRegion *srcPR, + PixelRegion *destPR, + gint subsample) +{ + const gint width = destPR->w; + const gint height = destPR->h; + const gint orig_width = srcPR->w / subsample; + const gint orig_height = srcPR->h / subsample; + const gdouble x_ratio = (gdouble) orig_width / (gdouble) width; + const gdouble y_ratio = (gdouble) orig_height / (gdouble) height; + const gint bytes = destPR->bytes; + const gint destwidth = destPR->rowstride; + guchar *src, *s; + guchar *dest, *d; + gdouble *row, *r; + gint src_row, src_col; + gdouble x_sum, y_sum; + gdouble x_last, y_last; + gdouble *x_frac, y_frac, tot_frac; + gint i, j; + gint b; + gint frac; + gint advance_dest; + +#if 0 + g_printerr ("subsample_region: (%d x %d) -> (%d x %d)\n", + orig_width, orig_height, width, height); +#endif + + /* the data pointers... */ + src = g_new (guchar, orig_width * bytes); + dest = destPR->data; + + /* allocate an array to help with the calculations */ + row = g_new (gdouble, width * bytes); + x_frac = g_new (gdouble, width + orig_width); + + /* initialize the pre-calculated pixel fraction array */ + src_col = 0; + x_sum = (gdouble) src_col; + x_last = x_sum; + + for (i = 0; i < width + orig_width; i++) + { + if (x_sum + x_ratio <= (src_col + 1 + EPSILON)) + { + x_sum += x_ratio; + x_frac[i] = x_sum - x_last; + } + else + { + src_col ++; + x_frac[i] = src_col - x_last; + } + + x_last += x_frac[i]; + } + + /* clear the "row" array */ + memset (row, 0, sizeof (gdouble) * width * bytes); + + /* counters... */ + src_row = 0; + y_sum = (gdouble) src_row; + y_last = y_sum; + + pixel_region_get_row (srcPR, + srcPR->x, srcPR->y + src_row * subsample, + orig_width * subsample, + src, subsample); + + /* Scale the selected region */ + for (i = 0; i < height; ) + { + src_col = 0; + x_sum = (gdouble) src_col; + + /* determine the fraction of the src pixel we are using for y */ + if (y_sum + y_ratio <= (src_row + 1 + EPSILON)) + { + y_sum += y_ratio; + y_frac = y_sum - y_last; + advance_dest = TRUE; + } + else + { + src_row ++; + y_frac = src_row - y_last; + advance_dest = FALSE; + } + + y_last += y_frac; + + s = src; + r = row; + + frac = 0; + j = width; + + while (j) + { + tot_frac = x_frac[frac++] * y_frac; + + for (b = 0; b < bytes; b++) + r[b] += s[b] * tot_frac; + + /* increment the destination */ + if (x_sum + x_ratio <= (src_col + 1 + EPSILON)) + { + r += bytes; + x_sum += x_ratio; + j--; + } + + /* increment the source */ + else + { + s += bytes; + src_col++; + } + } + + if (advance_dest) + { + tot_frac = 1.0 / (x_ratio * y_ratio); + + /* copy "row" to "dest" */ + d = dest; + r = row; + + j = width; + while (j--) + { + b = bytes; + + while (b--) + *d++ = (guchar) (*r++ * tot_frac + 0.5); + } + + dest += destwidth; + + /* clear the "row" array */ + memset (row, 0, sizeof (gdouble) * destwidth); + + i++; + } + else + { + pixel_region_get_row (srcPR, + srcPR->x, + srcPR->y + src_row * subsample, + orig_width * subsample, + src, subsample); + } + } + + /* free up temporary arrays */ + g_free (row); + g_free (x_frac); + g_free (src); +} + + +void +subsample_indexed_region (PixelRegion *srcPR, + PixelRegion *destPR, + const guchar *cmap, + gint subsample) +{ + guchar *src, *s; + guchar *dest, *d; + gdouble *row, *r; + gint destwidth; + gint src_row, src_col; + gint bytes, b; + gint width, height; + gint orig_width, orig_height; + gdouble x_rat, y_rat; + gdouble x_cum, y_cum; + gdouble x_last, y_last; + gdouble *x_frac, y_frac, tot_frac; + gint i, j; + gint frac; + gboolean advance_dest; + gboolean has_alpha; + + g_return_if_fail (cmap != NULL); + + orig_width = srcPR->w / subsample; + orig_height = srcPR->h / subsample; + width = destPR->w; + height = destPR->h; + + /* Some calculations... */ + bytes = destPR->bytes; + destwidth = destPR->rowstride; + + has_alpha = pixel_region_has_alpha (srcPR); + + /* the data pointers... */ + src = g_new (guchar, orig_width * bytes); + dest = destPR->data; + + /* find the ratios of old x to new x and old y to new y */ + x_rat = (gdouble) orig_width / (gdouble) width; + y_rat = (gdouble) orig_height / (gdouble) height; + + /* allocate an array to help with the calculations */ + row = g_new0 (gdouble, width * bytes); + x_frac = g_new (gdouble, width + orig_width); + + /* initialize the pre-calculated pixel fraction array */ + src_col = 0; + x_cum = (gdouble) src_col; + x_last = x_cum; + + for (i = 0; i < width + orig_width; i++) + { + if (x_cum + x_rat <= (src_col + 1 + EPSILON)) + { + x_cum += x_rat; + x_frac[i] = x_cum - x_last; + } + else + { + src_col++; + x_frac[i] = src_col - x_last; + } + + x_last += x_frac[i]; + } + + /* counters... */ + src_row = 0; + y_cum = (gdouble) src_row; + y_last = y_cum; + + pixel_region_get_row (srcPR, + srcPR->x, + srcPR->y + src_row * subsample, + orig_width * subsample, + src, + subsample); + + /* Scale the selected region */ + for (i = 0; i < height; ) + { + src_col = 0; + x_cum = (gdouble) src_col; + + /* determine the fraction of the src pixel we are using for y */ + if (y_cum + y_rat <= (src_row + 1 + EPSILON)) + { + y_cum += y_rat; + y_frac = y_cum - y_last; + advance_dest = TRUE; + } + else + { + src_row++; + y_frac = src_row - y_last; + advance_dest = FALSE; + } + + y_last += y_frac; + + s = src; + r = row; + + frac = 0; + + j = width; + while (j) + { + gint index = *s * 3; + + tot_frac = x_frac[frac++] * y_frac; + + /* transform the color to RGB */ + if (has_alpha) + { + if (s[ALPHA_I_PIX] & 0x80) + { + r[RED_PIX] += cmap[index++] * tot_frac; + r[GREEN_PIX] += cmap[index++] * tot_frac; + r[BLUE_PIX] += cmap[index++] * tot_frac; + r[ALPHA_PIX] += tot_frac; + } + /* else the pixel contributes nothing and needs not to be added + */ + } + else + { + r[RED_PIX] += cmap[index++] * tot_frac; + r[GREEN_PIX] += cmap[index++] * tot_frac; + r[BLUE_PIX] += cmap[index++] * tot_frac; + } + + /* increment the destination */ + if (x_cum + x_rat <= (src_col + 1 + EPSILON)) + { + r += bytes; + x_cum += x_rat; + j--; + } + /* increment the source */ + else + { + s += srcPR->bytes; + src_col++; + } + } + + if (advance_dest) + { + tot_frac = 1.0 / (x_rat * y_rat); + + /* copy "row" to "dest" */ + d = dest; + r = row; + + j = width; + while (j--) + { + if (has_alpha) + { + /* unpremultiply */ + + gdouble alpha = r[bytes - 1]; + + if (alpha > EPSILON) + { + for (b = 0; b < (bytes - 1); b++) + d[b] = (guchar) ((r[b] / alpha) + 0.5); + + d[bytes - 1] = (guchar) ((alpha * tot_frac * 255.0) + 0.5); + } + else + { + for (b = 0; b < bytes; b++) + d[b] = 0; + } + } + else + { + for (b = 0; b < bytes; b++) + d[b] = (guchar) ((r[b] * tot_frac) + 0.5); + } + + r += bytes; + d += bytes; + } + + dest += destwidth; + + /* clear the "row" array */ + memset (row, 0, sizeof (gdouble) * destwidth); + + i++; + } + else + { + pixel_region_get_row (srcPR, + srcPR->x, + srcPR->y + src_row * subsample, + orig_width * subsample, + src, + subsample); + } + } + + /* free up temporary arrays */ + g_free (row); + g_free (x_frac); + g_free (src); +} diff --git a/app/paint-funcs/sample-funcs.h b/app/paint-funcs/sample-funcs.h new file mode 100644 index 0000000000..0999443d9a --- /dev/null +++ b/app/paint-funcs/sample-funcs.h @@ -0,0 +1,33 @@ +/* GIMP - The GNU Image Manipulation Program + * Copyright (C) 1995 Spencer Kimball and Peter Mattis + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#ifndef __SAMPLE_FUNCS_H__ +#define __SAMPLE_FUNCS_H__ + + +void subsample_region (PixelRegion *srcPR, + PixelRegion *destPR, + gint subsample); + +void subsample_indexed_region (PixelRegion *srcPR, + PixelRegion *destPR, + const guchar *cmap, + gint subsample); + + +#endif /* __SAMPLE_FUNCS_H__ */ diff --git a/app/paint-funcs/scale-funcs.c b/app/paint-funcs/scale-funcs.c index f1dd29cf24..a4d1349eac 100644 --- a/app/paint-funcs/scale-funcs.c +++ b/app/paint-funcs/scale-funcs.c @@ -675,170 +675,6 @@ scale_region (PixelRegion *srcPR, g_free (row); } -void -subsample_region (PixelRegion *srcPR, - PixelRegion *destPR, - gint subsample) -{ - const gint width = destPR->w; - const gint height = destPR->h; - const gint orig_width = srcPR->w / subsample; - const gint orig_height = srcPR->h / subsample; - const gdouble x_ratio = (gdouble) orig_width / (gdouble) width; - const gdouble y_ratio = (gdouble) orig_height / (gdouble) height; - const gint bytes = destPR->bytes; - const gint destwidth = destPR->rowstride; - guchar *src, *s; - guchar *dest, *d; - gdouble *row, *r; - gint src_row, src_col; - gdouble x_sum, y_sum; - gdouble x_last, y_last; - gdouble *x_frac, y_frac, tot_frac; - gint i, j; - gint b; - gint frac; - gint advance_dest; - -#if 0 - g_printerr ("subsample_region: (%d x %d) -> (%d x %d)\n", - orig_width, orig_height, width, height); -#endif - - /* the data pointers... */ - src = g_new (guchar, orig_width * bytes); - dest = destPR->data; - - /* allocate an array to help with the calculations */ - row = g_new (gdouble, width * bytes); - x_frac = g_new (gdouble, width + orig_width); - - /* initialize the pre-calculated pixel fraction array */ - src_col = 0; - x_sum = (gdouble) src_col; - x_last = x_sum; - - for (i = 0; i < width + orig_width; i++) - { - if (x_sum + x_ratio <= (src_col + 1 + EPSILON)) - { - x_sum += x_ratio; - x_frac[i] = x_sum - x_last; - } - else - { - src_col ++; - x_frac[i] = src_col - x_last; - } - - x_last += x_frac[i]; - } - - /* clear the "row" array */ - memset (row, 0, sizeof (gdouble) * width * bytes); - - /* counters... */ - src_row = 0; - y_sum = (gdouble) src_row; - y_last = y_sum; - - pixel_region_get_row (srcPR, - srcPR->x, srcPR->y + src_row * subsample, - orig_width * subsample, - src, subsample); - - /* Scale the selected region */ - for (i = 0; i < height; ) - { - src_col = 0; - x_sum = (gdouble) src_col; - - /* determine the fraction of the src pixel we are using for y */ - if (y_sum + y_ratio <= (src_row + 1 + EPSILON)) - { - y_sum += y_ratio; - y_frac = y_sum - y_last; - advance_dest = TRUE; - } - else - { - src_row ++; - y_frac = src_row - y_last; - advance_dest = FALSE; - } - - y_last += y_frac; - - s = src; - r = row; - - frac = 0; - j = width; - - while (j) - { - tot_frac = x_frac[frac++] * y_frac; - - for (b = 0; b < bytes; b++) - r[b] += s[b] * tot_frac; - - /* increment the destination */ - if (x_sum + x_ratio <= (src_col + 1 + EPSILON)) - { - r += bytes; - x_sum += x_ratio; - j--; - } - - /* increment the source */ - else - { - s += bytes; - src_col++; - } - } - - if (advance_dest) - { - tot_frac = 1.0 / (x_ratio * y_ratio); - - /* copy "row" to "dest" */ - d = dest; - r = row; - - j = width; - while (j--) - { - b = bytes; - - while (b--) - *d++ = (guchar) (*r++ * tot_frac + 0.5); - } - - dest += destwidth; - - /* clear the "row" array */ - memset (row, 0, sizeof (gdouble) * destwidth); - - i++; - } - else - { - pixel_region_get_row (srcPR, - srcPR->x, - srcPR->y + src_row * subsample, - orig_width * subsample, - src, subsample); - } - } - - /* free up temporary arrays */ - g_free (row); - g_free (x_frac); - g_free (src); -} - - /* Lanczos */ static inline gdouble sinc (gdouble x) diff --git a/app/paint-funcs/scale-funcs.h b/app/paint-funcs/scale-funcs.h index bd68eb4b02..e7df1b1b1f 100644 --- a/app/paint-funcs/scale-funcs.h +++ b/app/paint-funcs/scale-funcs.h @@ -22,7 +22,7 @@ #define LANCZOS_SPP (4000) /* number of data pts per unit x in lookup table */ #define LANCZOS_MIN (1.0/LANCZOS_SPP) -#define LANCZOS_WIDTH (3) /* 3 for Lanczos3 code, for L4 prefer DUAL_LANCZOS below */ +#define LANCZOS_WIDTH (3) /* 3 for Lanczos3 code, for L4 prefer DUAL_LANCZOS below */ #define LANCZOS_WIDTH2 (1 + (LANCZOS_WIDTH * 2)) #define LANCZOS_SAMPLES (LANCZOS_SPP * (LANCZOS_WIDTH + 1)) @@ -33,19 +33,20 @@ void scale_region (PixelRegion *srcPR, GimpProgressFunc progress_callback, gpointer progress_data); -void subsample_region (PixelRegion *srcPR, - PixelRegion *destPR, - gint subsample); - gfloat * create_lanczos_lookup (void); + #endif /* __SCALE_FUNCS_H__ */ -/* determining LANCZOS_SPP value - 1000 points per unit will produce typically 1 bit of error per channel on a Lanczos3 window - 4000 should not produce a detectable error caused by lookup table size.on 8b colours ie 24bit RGB - this req 80kB of memory comparable to a small 250x150 px image. Filling the array is a small part of - the time required for the transform. - This will need reviewing when GIMP handles images with more bytes per pixel. -*/ +/* + * Determining LANCZOS_SPP value + * + * 1000 points per unit will produce typically 1 bit of error per channel + * on a Lanczos3 window. 4000 should not produce a detectable error caused + * by lookup table size. + * On 8b colours ie 24bit RGB this req 80kB of memory comparable to a small + * 250x150 px image. Filling the array is a small part of the time required + * for the transform. + * This will need reviewing when GIMP handles images with more bytes per pixel. + */