Initial import. Contains the im, cd and iup librairies, and a "working" Makefile for them under linux.

1 files changed, 1297 insertions, 0 deletions

diff --git a/im/src/im_lua3.c b/im/src/im_lua3.c
new file mode 100755
index 0000000..1c85e59
--- /dev/null
+++ b/im/src/im_lua3.c
@@ -0,0 +1,1297 @@
+/** \file
+ * \brief LuaBinding for Lua 3
+ *
+ * See Copyright Notice in im_lib.h
+ * $Id: im_lua3.c,v 1.1 2008/10/17 06:10:16 scuri Exp $
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <lua.h>
+
+#include "im.h"
+#include "im_lib.h"
+
+#include <cd.h>
+#include <cdlua3_private.h>
+
+#include "imlua.h"
+
+
+/***************************************************************************\
+* Globals.                                                                  *
+\***************************************************************************/
+static int color_tag;
+static int imagergb_tag;
+static int imagergba_tag;
+static int palette_tag;
+static int imagemap_tag;
+static int channel_tag;
+
+static channel_t channel_info;
+
+#define IMLUA_VERSION "IMLua 1.2"
+/***************************************************************************\
+* Creation and destruction functions.                                       *
+\***************************************************************************/
+
+/***************************************************************************\
+* Creates a buffer for a RGB image.                                         *
+\***************************************************************************/
+static void imlua_createimagergb(void)
+{
+  lua_Object width, height;
+  long int width_i, height_i;
+  imagergb_t *imagergb_p;
+
+  width = lua_getparam(1);
+  height = lua_getparam(2);
+  if (!(lua_isnumber(width) && lua_isnumber(height)))
+    lua_error("imCreateImageRGB: invalid dimensions parameter!");
+  width_i = (long int) lua_getnumber(width);
+  height_i = (long int) lua_getnumber(height);
+  if (width_i < 1 || height_i < 1)
+    lua_error("imCreateImageRGB: image dimensions should be positive integers!");
+
+  if (lua_getparam(3) != LUA_NOOBJECT)
+    lua_error("imCreateImageRGB: too many parameters!");
+  
+  imagergb_p = (imagergb_t *) malloc(sizeof(imagergb_t));
+  if (!imagergb_p) {
+    lua_pushnil();
+    return;
+  }
+
+  imagergb_p->width = width_i;
+  imagergb_p->height = height_i;
+  imagergb_p->size = width_i*height_i;
+  imagergb_p->red = (unsigned char *) malloc(imagergb_p->size);
+  imagergb_p->green = (unsigned char *) malloc(imagergb_p->size);
+  imagergb_p->blue = (unsigned char *) malloc(imagergb_p->size);
+  
+  if (!(imagergb_p->red && imagergb_p->green && imagergb_p->blue)) { 
+    if (imagergb_p->red) free(imagergb_p->red);
+    if (imagergb_p->green) free(imagergb_p->green);
+    if (imagergb_p->blue) free(imagergb_p->blue);
+    free(imagergb_p);
+    lua_pushnil();
+    return;
+  }
+
+  memset(imagergb_p->red, 255, imagergb_p->size);
+  memset(imagergb_p->green, 255, imagergb_p->size);
+  memset(imagergb_p->blue, 255, imagergb_p->size);
+  
+  lua_pushusertag((void *) imagergb_p, imagergb_tag);
+}
+
+/***************************************************************************\
+* Frees a previously allocated imagergb. We don't free imagergb_p to avoid  *
+* problems if the user called killimagergb twice with the same object. The  *
+* structure will be freed by a userdata "gc" fallback in LUA 3.0.           *
+\***************************************************************************/
+static void imlua_killimagergb(void)
+{
+  lua_Object imagergb;
+  imagergb_t *imagergb_p;
+
+  imagergb = lua_getparam(1);
+  if (imagergb == LUA_NOOBJECT)
+    lua_error("imKillImageRGB: imagergb parameter missing!");
+  if (lua_isnil(imagergb))
+    lua_error("imKillImageRGB: attempt to kill a NIL imagergb!");
+  if (lua_tag(imagergb) != imagergb_tag)
+    lua_error("imKillImageRGB: invalid imagergb parameter!");
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+  if (!(imagergb_p->red && imagergb_p->green && imagergb_p->blue)) 
+    lua_error("imKillImageRGB: attempt to kill a killed imagergb!");
+
+  if (lua_getparam(2) != LUA_NOOBJECT)
+    lua_error("imKillImageRGB: too many parameters!");
+
+  free(imagergb_p->red);
+  free(imagergb_p->green);
+  free(imagergb_p->blue);
+  imagergb_p->red = NULL;
+  imagergb_p->green = NULL;
+  imagergb_p->blue = NULL;
+}
+
+/***************************************************************************\
+* Creates a palette as a palette_tag usertag lua_Object. A palette can be   *
+* considered and treated as a color table.                                  *
+\***************************************************************************/
+static void imlua_createpalette(void)
+{
+  lua_Object size;
+  long int size_i;
+  palette_t *palette_p;
+
+  size = lua_getparam(1);
+  if (!(lua_isnumber(size)))
+    lua_error("imCreatePalette: invalid palette parameter!");
+  size_i = (long int) lua_getnumber(size);
+  if (size_i < 1)
+    lua_error("imCreatePalette: palette size should be a positive integer!");
+
+  if (lua_getparam(2) != LUA_NOOBJECT)
+    lua_error("imCreatePalette: too many parameters!");
+
+  palette_p = (palette_t *) malloc(sizeof(palette_t));
+  if (!palette_p) {
+    lua_pushnil();
+    return;
+  }
+
+  palette_p->size = size_i;
+  palette_p->color = (long int *) malloc(palette_p->size * sizeof(long int));
+  if (!palette_p->color) {
+    free(palette_p);
+    lua_pushnil();
+    return;
+  }
+
+  memset(palette_p->color, 255, palette_p->size * sizeof(long int));
+  lua_pushusertag((void *) palette_p, palette_tag);
+}
+
+/***************************************************************************\
+* Frees a previously allocated palette. We don't free palette_p to prevent  *
+* a problem if the user called killpalette twice with the same object. The  *
+* structure will be freed by a userdata "gc" fallback in LUA 3.0.           *
+\***************************************************************************/
+static void imlua_killpalette(void)
+{
+  lua_Object palette;
+  palette_t *palette_p;
+
+  palette = lua_getparam(1);
+  if (palette == LUA_NOOBJECT)
+    lua_error("imKillPalette: palette parameter missing!");
+  if (lua_isnil(palette))
+    lua_error("imKillPalette: attempt to kill a NIL palette!");
+  if (lua_tag(palette) != palette_tag)
+    lua_error("imKillPalette: invalid palette parameter!");
+  palette_p = (palette_t *) lua_getuserdata(palette);
+  if (!palette_p->color) 
+    lua_error("imKillPalette: attempt to kill a killed palette!");
+
+  if (lua_getparam(2) != LUA_NOOBJECT)
+    lua_error("imKillPalette: too many parameters!");
+
+  free(palette_p->color);
+  palette_p->color = NULL;
+}
+
+/***************************************************************************\
+* Creates a imagemap as a imagemap_tag usertag lua_Object.                  *
+\***************************************************************************/
+static void imlua_createimagemap(void)
+{
+  lua_Object width;
+  lua_Object height;
+
+  long int width_i;
+  long int height_i;
+  imagemap_t *imagemap_p;
+
+  width = lua_getparam(1);
+  height = lua_getparam(2);
+  if (!(lua_isnumber(width) && lua_isnumber(height)))
+    lua_error("imCreateImageMap: invalid dimensions parameter!");
+  width_i = (long int) lua_getnumber(width);
+  height_i = (long int) lua_getnumber(height);
+  if (width_i < 1 || height_i < 1)
+    lua_error("imCreateImageMap: imagemap dimensions should be positive integers!");
+
+  if (lua_getparam(3) != LUA_NOOBJECT)
+    lua_error("imCreateImageMap: too many parameters!");
+
+  imagemap_p = (imagemap_t *) malloc(sizeof(imagemap_t));
+  if (!imagemap_p) {
+    lua_pushnil();
+    return;
+  }
+
+  imagemap_p->size = width_i*height_i;
+  imagemap_p->width = width_i;
+  imagemap_p->height = height_i;
+  imagemap_p->index = (unsigned char *) malloc(imagemap_p->size);
+  if (!imagemap_p->index) {
+    free(imagemap_p);
+    lua_pushnil();
+    return;
+  }
+
+  memset(imagemap_p->index, 0, imagemap_p->size);
+  lua_pushusertag((void *) imagemap_p, imagemap_tag);
+}
+
+/***************************************************************************\
+* Frees a previously allocated imagemap. We don't free imagemap_p to avoid  *
+* problems if the user called killimagemap twice with the same object. The  *
+* structure will be freed by a userdata "gc" fallback in LUA 3.0.           *
+\***************************************************************************/
+static void imlua_killimagemap(void)
+{
+  lua_Object imagemap;
+  imagemap_t *imagemap_p;
+
+  imagemap = lua_getparam(1);
+  if (imagemap == LUA_NOOBJECT)
+    lua_error("imKillImageMap: imagemap parameter missing!");
+  if (lua_isnil(imagemap))
+    lua_error("imKillImageMap: attempt to kill a NIL imagemap!");
+  if (lua_tag(imagemap) != imagemap_tag)
+    lua_error("imKillImageMap: invalid imagemap parameter!");
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+  if (!imagemap_p->index) 
+    lua_error("imKillImageMap: attempt to kill a killed imagemap!");
+    
+  if (lua_getparam(2) != LUA_NOOBJECT)
+    lua_error("imKillImageMap: too many parameters!");
+
+  free(imagemap_p->index);
+  imagemap_p->index = NULL;
+}
+
+/***************************************************************************\
+* IM API Functions.                                                         *
+\***************************************************************************/
+
+/***************************************************************************\
+* imFileFormat                                                              *
+\***************************************************************************/
+static void imlua_fileformat(void)
+{
+  lua_Object file;
+
+  char *file_s;
+  int format_i;
+  int compress_i;
+
+  int err;
+
+  file = lua_getparam(1);
+  if (!lua_isstring(file))
+    lua_error("imFileFormat: invalid filename parameter!");
+  file_s = (char *) lua_getstring(file);
+
+  if (lua_getparam(2) != LUA_NOOBJECT)
+    lua_error("imFileFormat: too many parameters!");
+
+  err = imFileFormat(file_s, &format_i);
+
+  compress_i = (format_i & IM_DEFAULT) ? 1 : 0;
+  format_i = format_i & 0xFF;
+  
+  /* if success, return the format */
+  if (err == IM_ERR_NONE) {
+    lua_pushnumber( format_i);
+    lua_pushnumber( compress_i);
+  }
+  /* if failure, return nil */
+  else {
+    lua_pushnil();
+    lua_pushnil();
+  }
+
+  lua_pushnumber( err);
+}
+
+/***************************************************************************\
+* imFileFormat                                                              *
+\***************************************************************************/
+static void imlua_imageinfo(void)
+{
+  lua_Object file;
+
+  char *file_s;
+  
+  int width, height, image_type, pal_size;
+  int err;
+  
+  file = lua_getparam(1);
+  if (!lua_isstring(file))
+    lua_error("imFileFormat: invalid filename parameter!");
+  file_s = (char *) lua_getstring(file);
+
+  if (lua_getparam(2) != LUA_NOOBJECT)
+    lua_error("imFileFormat: too many parameters!");
+
+  err = imImageInfo(file_s, &width, &height, &image_type, &pal_size);
+  
+  /* if success, return the format */
+  if (err == IM_ERR_NONE) {
+    lua_pushnumber( width);
+    lua_pushnumber( height);
+    lua_pushnumber( image_type);
+    lua_pushnumber( pal_size);
+  }
+  /* if failure, return nil */
+  else {
+    lua_pushnil();
+    lua_pushnil();
+    lua_pushnil();
+    lua_pushnil();
+  }
+
+  lua_pushnumber( err);
+}
+
+/***************************************************************************\
+* imEncodeColor                                                             *
+\***************************************************************************/
+static void imlua_encodecolor(void)
+{
+  lua_Object red, green, blue;
+  float red_f, green_f, blue_f;
+  unsigned char red_i, green_i, blue_i;
+  long int color_i;
+
+  red = lua_getparam(1);
+  green = lua_getparam(2);
+  blue = lua_getparam(3);
+
+  if (lua_getparam(4) != LUA_NOOBJECT)
+    lua_error("imEncodeColor: too many parameters!");
+
+  if (!(lua_isnumber(red) && lua_isnumber(green) && lua_isnumber(blue)))
+    lua_error("imEncodeColor: invalid color component parameter!");
+
+  red_f = (float)lua_getnumber(red);
+  green_f = (float)lua_getnumber(green);
+  blue_f = (float)lua_getnumber(blue);
+
+  if (red_f < 0 || red_f > 255 || green_f < 0 || 
+      green_f > 255 || blue_f < 0 || blue_f > 255)
+    lua_error("imEncodeColor: color components values should be in range [0, 255]!");
+
+  red_i = (unsigned char) (red_f);
+  green_i = (unsigned char) (green_f);
+  blue_i = (unsigned char) (blue_f);
+
+  color_i = imEncodeColor(red_i, green_i, blue_i);
+  lua_pushusertag((void *) color_i, color_tag);
+}
+
+/***************************************************************************\
+* imDecodeColor                                                             *
+\***************************************************************************/
+static void imlua_decodecolor(void)
+{
+  lua_Object color;
+  long int color_i;
+  unsigned char red_i, green_i, blue_i;
+
+  color = lua_getparam(1);
+  if (lua_tag(color) != color_tag)
+    lua_error("imDecodeColor: invalid color parameter!");
+  color_i = (long int) lua_getuserdata(color);
+
+  if (lua_getparam(2) != LUA_NOOBJECT)
+    lua_error("imDecodeColor: too many parameters!");
+
+  imDecodeColor(&red_i, &green_i, &blue_i, color_i);
+
+  lua_pushnumber( red_i);
+  lua_pushnumber( green_i);
+  lua_pushnumber( blue_i);
+}
+
+/***************************************************************************\
+* imLoadRGB                                                                 *
+\***************************************************************************/
+static void imlua_loadrgb(void)
+{
+  lua_Object file, imagergb;
+
+  imagergb_t *imagergb_p;
+  char *file_s;
+
+  int err;
+
+  file = lua_getparam(1);
+  if (!lua_isstring(file))
+    lua_error("imLoadRGB: invalid filename parameter!");
+  file_s = (char *) lua_getstring(file);
+
+  imagergb = lua_getparam(2);
+  if (lua_tag(imagergb) != imagergb_tag)
+    lua_error("imLoadRGB: invalid imagergb parameter!");
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+
+  if (lua_getparam(3) != LUA_NOOBJECT)
+    lua_error("imLoadRGB: too many parameters!");
+
+  err = imLoadRGB(file_s, imagergb_p->red, imagergb_p->green, imagergb_p->blue);
+  lua_pushnumber( err);
+}
+
+/***************************************************************************\
+* imLoadMap                                                                 *
+\***************************************************************************/
+static void imlua_loadmap(void)
+{
+  lua_Object file, imagemap, palette;
+
+  imagemap_t *imagemap_p;
+  palette_t *palette_p;
+  char *file_s;
+
+  int err;
+
+  file = lua_getparam(1);
+  if (!lua_isstring(file))
+    lua_error("imLoadMap: invalid filename parameter!");
+  file_s = (char *) lua_getstring(file);
+
+  imagemap = lua_getparam(2);
+  if (lua_tag(imagemap) != imagemap_tag)
+    lua_error("imLoadMap: invalid imagemap parameter!");
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+
+  palette = lua_getparam(3);
+  if (lua_tag(palette) != palette_tag)
+    lua_error("imLoadMap: invalid palette parameter!");
+  palette_p = (palette_t *) lua_getuserdata(palette);
+
+  if (lua_getparam(4) != LUA_NOOBJECT)
+    lua_error("imLoadMap: too many parameters!");
+
+  err = imLoadMap(file_s, imagemap_p->index, palette_p->color);
+  lua_pushnumber( err);
+}
+
+/***************************************************************************\
+* imSaveRGB                                                                 *
+\***************************************************************************/
+static void imlua_savergb(void)
+{
+  lua_Object file, imagergb, format, compress;
+
+  imagergb_t *imagergb_p;
+  char *file_s;
+  int format_i;
+  int compress_i;
+
+  int err;
+
+  imagergb = lua_getparam(1);
+  if (lua_tag(imagergb) != imagergb_tag)
+    lua_error("imSaveRGB: invalid imagergb parameter!");
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+
+  format = lua_getparam(2);
+  if (!lua_isnumber(format))
+    lua_error("imSaveRGB: invalid format parameter!");
+  format_i = (int) lua_getnumber(format);
+  
+  compress = lua_getparam(3);
+  if (!lua_isnumber(compress))
+    lua_error("imSaveRGB: invalid compression parameter!");
+  compress_i = (int) lua_getnumber(compress);
+
+  file = lua_getparam(4);
+  if (!lua_isstring(file))
+    lua_error("imSaveRGB: invalid filename parameter!");
+  file_s = (char *) lua_getstring(file);
+
+  if (lua_getparam(5) != LUA_NOOBJECT)
+    lua_error("imSaveRGB: too many parameters!");
+
+  err = imSaveRGB(imagergb_p->width, imagergb_p->height, format_i | (compress_i << 8), 
+    imagergb_p->red, imagergb_p->green, imagergb_p->blue, file_s);
+  lua_pushnumber( err);
+}
+
+/***************************************************************************\
+* imSaveMap                                                                 *
+\***************************************************************************/
+static void imlua_savemap(void)
+{
+  lua_Object file, imagemap, palette, format, compress;
+
+  imagemap_t *imagemap_p;
+  palette_t *palette_p;
+  char *file_s;
+  int format_i;
+  int compress_i;
+
+  int err;
+
+  imagemap = lua_getparam(1);
+  if (lua_tag(imagemap) != imagemap_tag)
+    lua_error("imSaveMap: invalid imagemap  parameter!");
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+
+  palette = lua_getparam(2);
+  if (lua_tag(palette) != palette_tag)
+    lua_error("imLoadMap: invalid palette parameter!");
+  palette_p = (palette_t *) lua_getuserdata(palette);
+
+  format = lua_getparam(3);
+  if (!lua_isnumber(format))
+    lua_error("imSaveMap: invalid format parameter!");
+  format_i = (int) lua_getnumber(format);
+  
+  compress = lua_getparam(4);
+  if (!lua_isnumber(compress))
+    lua_error("imSaveMap: invalid compression parameter!");
+  compress_i = (int) lua_getnumber(compress);
+
+  file = lua_getparam(5);
+  if (!lua_isstring(file))
+    lua_error("imSaveMap: invalid filename parameter!");
+  file_s = (char *) lua_getstring(file);
+
+  if (lua_getparam(6) != LUA_NOOBJECT)
+    lua_error("imSaveMap: too many parameters!");
+
+  err = imSaveMap(imagemap_p->width, imagemap_p->height, format_i | (compress_i << 8), 
+    imagemap_p->index, palette_p->size, palette_p->color, file_s);
+  lua_pushnumber( err);
+}
+
+/***************************************************************************\
+* imRGB2Map                                                                 *
+\***************************************************************************/
+static void imlua_rgb2map(void)
+{
+  lua_Object imagergb, imagemap, palette;
+
+  imagemap_t *imagemap_p;
+  palette_t *palette_p;
+  imagergb_t *imagergb_p;
+
+  imagergb = lua_getparam(1);
+  if (lua_tag(imagergb) != imagergb_tag)
+    lua_error("imRGB2Map: invalid imagergb parameter!");
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+
+  imagemap = lua_getparam(2);
+  if (lua_tag(imagemap) != imagemap_tag)
+    lua_error("imRGB2Map: invalid imagemap parameter!");
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+
+  palette = lua_getparam(3);
+  if (lua_tag(palette) != palette_tag)
+    lua_error("imRGB2Map: invalid palette parameter!");
+  palette_p = (palette_t *) lua_getuserdata(palette);
+
+  if (lua_getparam(4) != LUA_NOOBJECT)
+    lua_error("imRGB2Map: too many parameters!");
+
+  if (imagergb_p->size != imagemap_p->size)
+    lua_error("imRGB2Map: images have incompatible dimensions!");
+  
+  imRGB2Map(imagergb_p->width, imagergb_p->height, imagergb_p->red, 
+    imagergb_p->green, imagergb_p->blue, imagemap_p->index, palette_p->size, 
+    palette_p->color);
+}
+
+/***************************************************************************\
+* imMap2RGB                                                                 *
+\***************************************************************************/
+static void imlua_map2rgb(void)
+{
+  lua_Object imagergb, imagemap, palette;
+
+  imagemap_t *imagemap_p;
+  palette_t *palette_p;
+  imagergb_t *imagergb_p;
+
+  imagemap = lua_getparam(1);
+  if (lua_tag(imagemap) != imagemap_tag)
+    lua_error("imMap2RGB: invalid imagemap parameter!");
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+
+  palette = lua_getparam(2);
+  if (lua_tag(palette) != palette_tag)
+    lua_error("imMap2RGB: invalid palette parameter!");
+  palette_p = (palette_t *) lua_getuserdata(palette);
+
+  imagergb = lua_getparam(3);
+  if (lua_tag(imagergb) != imagergb_tag)
+    lua_error("imMap2RGB: invalid imagergb parameter!");
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+
+  if (lua_getparam(4) != LUA_NOOBJECT)
+    lua_error("imMap2RGB: too many parameters!");
+
+  if (imagergb_p->size != imagemap_p->size)
+    lua_error("imMap2RGB: images have incompatible dimensions!");
+  
+  imMap2RGB(imagemap_p->width, imagemap_p->height, imagemap_p->index, palette_p->size, 
+    palette_p->color, imagergb_p->red, imagergb_p->green, imagergb_p->blue);
+}
+
+/***************************************************************************\
+* imMap2Gray                                                                *
+\***************************************************************************/
+static void imlua_map2gray(void)
+{
+  lua_Object imagemap, palette, graymap, grays;
+
+  imagemap_t *imagemap_p;
+  palette_t *palette_p;
+  imagemap_t *graymap_p;
+  palette_t *grays_p;
+
+  imagemap = lua_getparam(1);
+  if (lua_tag(imagemap) != imagemap_tag)
+    lua_error("imMap2Gray: invalid imagemap parameter!");
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+
+  palette = lua_getparam(2);
+  if (lua_tag(palette) != palette_tag)
+    lua_error("imMap2Gray: invalid palette parameter!");
+  palette_p = (palette_t *) lua_getuserdata(palette);
+
+  graymap = lua_getparam(3);
+  if (lua_tag(graymap) != imagemap_tag)
+    lua_error("imMap2Gray: invalid graymap parameter!");
+  graymap_p = (imagemap_t *) lua_getuserdata(graymap);
+
+  grays = lua_getparam(4);
+  if (lua_tag(grays) != palette_tag)
+    lua_error("imMap2Gray: invalid grays parameter!");
+  grays_p = (palette_t *) lua_getuserdata(grays);
+
+  if (lua_getparam(5) != LUA_NOOBJECT)
+    lua_error("imMap2Gray: too many parameters!");
+
+  if (imagemap_p->size != graymap_p->size)
+    lua_error("imMap2Gray: images have incompatible dimensions!");
+  
+  if (grays_p->size < 256)
+    lua_error("imMap2Gray: grays palette should be of size 256!");
+
+  imMap2Gray(imagemap_p->width, imagemap_p->height, imagemap_p->index, 
+    palette_p->size, palette_p->color, graymap_p->index, grays_p->color);
+}
+
+/***************************************************************************\
+* imRGB2Gray                                                                *
+\***************************************************************************/
+static void imlua_rgb2gray(void)
+{
+  lua_Object imagergb, graymap, grays;
+
+  imagergb_t *imagergb_p;
+  imagemap_t *graymap_p;
+  palette_t *grays_p;
+
+  imagergb = lua_getparam(1);
+  if (lua_tag(imagergb) != imagergb_tag)
+    lua_error("imRGB2Gray: invalid imagergb parameter!");
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+
+  graymap = lua_getparam(2);
+  if (lua_tag(graymap) != imagemap_tag)
+    lua_error("imRGB2Gray: invalid graymap parameter!");
+  graymap_p = (imagemap_t *) lua_getuserdata(graymap);
+
+  grays = lua_getparam(3);
+  if (lua_tag(grays) != palette_tag)
+    lua_error("imRGB2Gray: invalid grays parameter!");
+  grays_p = (palette_t *) lua_getuserdata(grays);
+
+  if (lua_getparam(4) != LUA_NOOBJECT)
+    lua_error("imRGB2Gray: too many parameters!");
+
+  if (imagergb_p->size != graymap_p->size)
+    lua_error("imRGB2Gray: images have incompatible dimensions!");
+  
+  if (grays_p->size < 256)
+    lua_error("imRGB2Gray: grays palette should be of size 256!");
+
+  imRGB2Gray(imagergb_p->width, imagergb_p->height, imagergb_p->red,
+    imagergb_p->green, imagergb_p->blue, graymap_p->index, grays_p->color);
+}
+
+/***************************************************************************\
+* imStretch.                                                                *
+\***************************************************************************/
+static void imlua_stretch(void)
+{
+  lua_Object src, dst;
+
+  imagemap_t *srcmap_p;
+  imagemap_t *dstmap_p;
+  imagergb_t *srcrgb_p;
+  imagergb_t *dstrgb_p;
+
+  src = lua_getparam(1);
+  dst = lua_getparam(2);
+  if (lua_getparam(3) != LUA_NOOBJECT)
+    lua_error("imStretch: too many parameters!");
+
+  if ((lua_tag(src) == imagergb_tag) && (lua_tag(dst) == imagergb_tag)) {
+    srcrgb_p = (imagergb_t *) lua_getuserdata(src);
+    dstrgb_p = (imagergb_t *) lua_getuserdata(dst);
+    imStretch(srcrgb_p->width, srcrgb_p->height, srcrgb_p->red,
+      dstrgb_p->width, dstrgb_p->height, dstrgb_p->red);
+    imStretch(srcrgb_p->width, srcrgb_p->height, srcrgb_p->green,
+      dstrgb_p->width, dstrgb_p->height, dstrgb_p->green);
+    imStretch(srcrgb_p->width, srcrgb_p->height, srcrgb_p->blue,
+      dstrgb_p->width, dstrgb_p->height, dstrgb_p->blue);
+  } 
+  else if ((lua_tag(src) == imagemap_tag) && (lua_tag(dst) == imagemap_tag)) {
+    srcmap_p = (imagemap_t *) lua_getuserdata(src);
+    dstmap_p = (imagemap_t *) lua_getuserdata(dst);
+    imStretch(srcmap_p->width, srcmap_p->height, srcmap_p->index,
+      dstmap_p->width, dstmap_p->height, dstmap_p->index);
+  }
+  else {
+    lua_error("imStretch: inconsistent parameters!");
+  }
+}
+
+/***************************************************************************\
+* imResize.                                                                *
+\***************************************************************************/
+static void imlua_resize(void)
+{
+  lua_Object src, dst;
+
+  imagergb_t *srcrgb_p;
+  imagergb_t *dstrgb_p;
+
+  src = lua_getparam(1);
+  dst = lua_getparam(2);
+  if (lua_getparam(3) != LUA_NOOBJECT)
+    lua_error("imResize: too many parameters!");
+
+  if ((lua_tag(src) == imagergb_tag) && (lua_tag(dst) == imagergb_tag)) {
+    srcrgb_p = (imagergb_t *) lua_getuserdata(src);
+    dstrgb_p = (imagergb_t *) lua_getuserdata(dst);
+    imStretch(srcrgb_p->width, srcrgb_p->height, srcrgb_p->red,
+      dstrgb_p->width, dstrgb_p->height, dstrgb_p->red);
+    imStretch(srcrgb_p->width, srcrgb_p->height, srcrgb_p->green,
+      dstrgb_p->width, dstrgb_p->height, dstrgb_p->green);
+    imStretch(srcrgb_p->width, srcrgb_p->height, srcrgb_p->blue,
+      dstrgb_p->width, dstrgb_p->height, dstrgb_p->blue);
+  } 
+  else {
+    lua_error("imResize: parameters must be of type imagergb_tag!");
+  }
+}
+
+/***************************************************************************\
+* imVersion.                                                                *
+\***************************************************************************/
+static void imlua_version(void)
+{
+  if (lua_getparam(1) != LUA_NOOBJECT)
+    lua_error("imVersion: too many parameters!");
+ 
+  lua_pushstring(imVersion());
+}
+
+/***************************************************************************\
+* Fallback implementation.                                                  *
+\***************************************************************************/
+
+/***************************************************************************\
+* imagemap "settable" fallback.                                             *
+\***************************************************************************/
+static void imagemapsettable_fb(void)
+{
+  lua_Object imagemap, index, value;
+
+  imagemap_t *imagemap_p;
+  long int index_i;
+  long int value_i;
+
+  imagemap = lua_getparam(1);
+  index = lua_getparam(2);
+  value = lua_getparam(3);
+
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+  if (!imagemap_p) {
+    lua_error("imagemap_tag \"settable\": invalid imagemap_tag object!");
+  }
+
+  if (!lua_isnumber(index)) {
+    lua_error("imagemap_tag \"settable\": index should be a number!");
+  }
+
+  if (!lua_isnumber(value)) {
+    lua_error("imagemap_tag \"settable\": value should be a number!");
+  }
+  
+  value_i = (long int) lua_getnumber(value);
+  if ((value_i < 0 || value_i > 255)) 
+    lua_error("imagemap_tag \"settable\": value should be in range [0, 255]!");
+
+  index_i = (long int) lua_getnumber(index);
+  if (index_i < 0 || index_i >= imagemap_p->size)
+    lua_error("imagemap_tag \"settable\": index is out of bounds!");
+
+  imagemap_p->index[index_i] = (unsigned char) value_i;
+}
+
+/***************************************************************************\
+* palette "settable" fallback.                                              *
+\***************************************************************************/
+static void palettesettable_fb(void)
+{
+  lua_Object palette, index, color;
+  
+  palette_t *palette_p;
+  long int index_i;
+  long int color_i;
+
+  palette = lua_getparam(1);
+  index = lua_getparam(2);
+  color = lua_getparam(3);
+
+  palette_p = (palette_t *) lua_getuserdata(palette);
+  if (!palette_p) {
+    lua_error("palette_tag \"settable\": invalid palette_tag object!");
+  }
+
+  if (!lua_isnumber(index)) {
+    lua_error("palette_tag \"settable\": index should be a number!");
+  }
+
+  if (lua_tag(color) != color_tag) 
+    lua_error("palette_tag \"settable\": value should be of type color_tag!");
+  
+  color_i = (long int) lua_getuserdata(color);
+  
+  index_i = (long int) lua_getnumber(index);
+  if (index_i < 0 || index_i >= palette_p->size)
+    lua_error("palette_tag \"settable\": index is out of bounds!");
+
+  palette_p->color[index_i] = color_i;
+}
+
+/***************************************************************************\
+* channel "settable" fallback. This fallback is called when a LUA line like *
+* "imagergb.r[y*w + x] = c" is executed. The imagergb "gettable" fallback   *
+* fills and returns a channel structure with info about the buffer. This    *
+* structure is consulted and the value is assigned where it should.         *
+\***************************************************************************/
+static void channelsettable_fb(void)
+{
+  lua_Object channel, index, value;
+  
+  channel_t *channel_p;
+  long int index_i;
+  long int value_i;
+
+  channel = lua_getparam(1);
+  index = lua_getparam(2);
+  value = lua_getparam(3);
+
+  channel_p = (channel_t *) lua_getuserdata(channel);
+  if (!channel_p) {
+    lua_error("channel_tag \"settable\": invalid channel_tag object!");
+  }
+
+  if (!lua_isnumber(index)) {
+    lua_error("channel_tag \"settable\": index should be a number!");
+  }
+  index_i = (long int) lua_getnumber(index);
+  if (index_i < 0 || index_i >= channel_p->size) {
+    lua_error("channel_tag \"settable\": index is out of bounds!");
+  }
+  
+  if (!lua_isnumber(value)) {
+    lua_error("channel_tag \"settable\": value should be a number!");
+  }
+  value_i = (long int) lua_getnumber(value);
+  if ((value_i < 0 || value_i > 255)) {
+    lua_error("channel_tag \"settable\": value should be in range [0, 255]!");
+  }
+
+  channel_p->value[index_i] = (unsigned char) value_i;
+}
+
+/***************************************************************************\
+* imagemap "gettable" fallback.                                             *
+\***************************************************************************/
+static void imagemapgettable_fb(void)
+{
+  lua_Object imagemap, index;
+
+  imagemap_t *imagemap_p;
+  long int index_i;
+
+  imagemap = lua_getparam(1);
+  index = lua_getparam(2);
+
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+  if (!imagemap_p)
+    lua_error("imagemap_tag \"gettable\": invalid imagemap_tag object!");
+
+  if (!lua_isnumber(index)) {
+    lua_error("imagemap_tag \"gettable\": index should be a number!");
+  }
+
+  index_i = (long int) lua_getnumber(index);
+  if (index_i < 0 || index_i >= imagemap_p->size)
+    lua_error("imagemap_tag \"gettable\": index is out of bounds!");
+
+  lua_pushnumber( imagemap_p->index[index_i]);
+}
+
+/***************************************************************************\
+* palette "gettable" fallback.                                              *
+\***************************************************************************/
+static void palettegettable_fb(void)
+{
+  lua_Object palette, index;
+  
+  palette_t *palette_p;
+  long int index_i;
+
+  palette = lua_getparam(1);
+  index = lua_getparam(2);
+
+  palette_p = (palette_t *) lua_getuserdata(palette);
+  if (!palette_p)
+    lua_error("palette_tag \"gettable\": invalid palette_tag object!");
+
+  if (!lua_isnumber(index)) {
+    lua_error("palette_tag \"gettable\": index should be a number!");
+  }
+
+  index_i = (long int) lua_getnumber(index);
+  if (index_i < 0 || index_i >= palette_p->size)
+    lua_error("palette_tag \"gettable\": index is out of bounds!");
+
+  lua_pushusertag((void *) palette_p->color[index_i], color_tag);
+}
+
+/***************************************************************************\
+* channel "gettable" fallback. This fallback is called when a LUA line like *
+* "c = imagergb.r[y*w + x]" is executed. The imagergb "gettable" fallback   *
+* fills and returns a channel structure with info about the buffer. This    *
+* structure is consulted and the appropriate value is returned.             *
+\***************************************************************************/
+static void channelgettable_fb(void)
+{
+  lua_Object channel, index;
+  
+  channel_t *channel_p;
+  long int index_i;
+
+  channel = lua_getparam(1);
+  index = lua_getparam(2);
+
+  channel_p = (channel_t *) lua_getuserdata(channel);
+  if (!channel_p) {
+    lua_error("channel_tag \"gettable\": invalid channel_tag object!");
+  }
+
+  if (!lua_isnumber(index)) {
+    lua_error("channel_tag \"gettable\": index should be a number!");
+  }
+  index_i = (long int) lua_getnumber(index);
+  if (index_i < 0 || index_i >= channel_p->size) {
+    lua_error("channel_tag \"gettable\": index is out of bounds!");
+  }
+  
+  lua_pushnumber( channel_p->value[index_i]);
+}
+
+/***************************************************************************\
+* imagergb "gettable" fallback. This fallback is called when a LUA line     *
+* like "c = imagergb.r[y*w + x]" or "imagergb.r[y*w + x] = c" is executed.  *
+* The channel_info global is filled and its address is returned with a      *
+* channel_tag usertag lua_Object. The following "gettable" or "settable"    *
+* then assigns or returns the appropriate value.                            *
+\***************************************************************************/
+static void imagergbgettable_fb(void)
+{
+  lua_Object imagergb, index;
+  
+  char *index_s;
+  imagergb_t *imagergb_p;
+
+  imagergb = lua_getparam(1);
+  index = lua_getparam(2);
+
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+  if (!imagergb_p)
+    lua_error("imagergb_tag \"gettable\": invalid imagergb_tag object!");
+
+  if (!lua_isstring(index)) {
+    lua_error("imagergb_tag \"gettable\": index should be a channel name!");
+  }
+  index_s = (char *) lua_getstring(index);
+
+  channel_info.size = imagergb_p->size;
+  
+  if (*index_s == 'r' || *index_s == 'R') {
+    channel_info.value = imagergb_p->red;
+  }
+  else if (*index_s == 'g' || *index_s == 'G') {
+    channel_info.value = imagergb_p->green;
+  }
+  else if (*index_s == 'b' || *index_s == 'B') {
+    channel_info.value = imagergb_p->blue;
+  }
+  else {
+    lua_error("imagergb_tag \"gettable\": index is an invalid channel name!");
+  }
+
+  lua_pushusertag((void *) &channel_info, channel_tag);
+}
+
+/***************************************************************************\
+* imagergba "gettable" fallback. This fallback is called when a LUA line    *
+* like "c = imagergba.r[y*w + x]" or "imagergba.r[y*w + x] = c" is executed.*
+* The channel_info global is filled and its address is returned with a      *
+* channel_tag usertag lua_Object. The following "gettable" or "settable"    *
+* then assigns or returns the appropriate value.                            *
+\***************************************************************************/
+static void imagergbagettable_fb(void)
+{
+  lua_Object imagergba, index;
+  
+  char *index_s;
+  imagergba_t *imagergba_p;
+
+  imagergba = lua_getparam(1);
+  index = lua_getparam(2);
+
+  imagergba_p = (imagergba_t *) lua_getuserdata(imagergba);
+  if (!imagergba_p)
+    lua_error("imagergba_tag \"gettable\": invalid imagergba_tag object!");
+
+  if (!lua_isstring(index)) {
+    lua_error("imagergba_tag \"gettable\": index should be a channel name!");
+  }
+  index_s = (char *) lua_getstring(index);
+
+  channel_info.size = imagergba_p->size;
+  
+  if (*index_s == 'r' || *index_s == 'R') {
+    channel_info.value = imagergba_p->red;
+  }
+  else if (*index_s == 'g' || *index_s == 'G') {
+    channel_info.value = imagergba_p->green;
+  }
+  else if (*index_s == 'b' || *index_s == 'B') {
+    channel_info.value = imagergba_p->blue;
+  }
+  else if (*index_s == 'a' || *index_s == 'A') {
+    channel_info.value = imagergba_p->alpha;
+  }
+  else {
+    lua_error("imagergba_tag \"gettable\": index is an invalid channel name!");
+  }
+
+  lua_pushusertag((void *) &channel_info, channel_tag);
+}
+
+/***************************************************************************\
+* palette "gc" fallback.                                                    *
+\***************************************************************************/
+static void palettegc_fb(void)
+{
+  lua_Object palette;
+
+  palette_t *palette_p;
+
+  palette = lua_getparam(1);
+  palette_p = (palette_t *) lua_getuserdata(palette);
+  if (!palette_p)
+    lua_error("palette_tag \"gc\": invalid palette_tag object!");
+
+  /* if the palette has not been killed, kill it */
+  if (palette_p->color) free(palette_p->color);
+
+  /* free the palette_t structure */
+  free(palette_p);
+}
+
+/***************************************************************************\
+* imagergb "gc" fallback.                                                   *
+\***************************************************************************/
+static void imagergbgc_fb(void)
+{
+  lua_Object imagergb;
+
+  imagergb_t *imagergb_p;
+
+  imagergb = lua_getparam(1);
+  imagergb_p = (imagergb_t *) lua_getuserdata(imagergb);
+  if (!imagergb_p)
+    lua_error("imagergb_tag \"gc\": invalid imagergb_tag object!");
+
+  /* if the imagergb has not been killed, kill it */
+  if (imagergb_p->red) free(imagergb_p->red);
+  if (imagergb_p->green) free(imagergb_p->green);
+  if (imagergb_p->blue) free(imagergb_p->blue);
+
+  /* free the imagergb_t structure */
+  free(imagergb_p);
+}
+
+/***************************************************************************\
+* imagergba "gc" fallback.                                                   *
+\***************************************************************************/
+static void imagergbagc_fb(void)
+{
+  lua_Object imagergba;
+
+  imagergba_t *imagergba_p;
+
+  imagergba = lua_getparam(1);
+  imagergba_p = (imagergba_t *) lua_getuserdata(imagergba);
+  if (!imagergba_p)
+    lua_error("imagergba_tag \"gc\": invalid imagergba_tag object!");
+
+  /* if the imagergba has not been killed, kill it */
+  if (imagergba_p->red) free(imagergba_p->red);
+  if (imagergba_p->green) free(imagergba_p->green);
+  if (imagergba_p->blue) free(imagergba_p->blue);
+  if (imagergba_p->alpha) free(imagergba_p->alpha);
+
+  /* free the imagergba_t structure */
+  free(imagergba_p);
+}
+
+/***************************************************************************\
+* imagemap "gc" fallback.                                                   *
+\***************************************************************************/
+static void imagemapgc_fb(void)
+{
+  lua_Object imagemap;
+
+  imagemap_t *imagemap_p;
+
+  imagemap = lua_getparam(1);
+  imagemap_p = (imagemap_t *) lua_getuserdata(imagemap);
+  if (!imagemap_p)
+    lua_error("imagemap_tag \"gc\": invalid imagemap_tag object!");
+
+  /* if the imagemap has not been killed, kill it */
+  if (imagemap_p->index) free(imagemap_p->index);
+
+  /* free the imagemap_t structure */
+  free(imagemap_p);
+}
+
+/***************************************************************************\
+* Initialization code.                                                      *
+\***************************************************************************/
+
+/***************************************************************************\
+* Initializes IMLua.                                                        *
+\***************************************************************************/
+void imlua_open(void)
+{
+  lua_Object cdlua_tag;
+  
+  /* check if CD has been initialized */
+  cdlua_tag = lua_getglobal("CDLUA_INSTALLED");
+
+  /* get CD defined tags, let CD deal with the user tag objects  */
+  if ((cdlua_tag != LUA_NOOBJECT) && (!lua_isnil(cdlua_tag))) {
+    cdlua_tag = lua_getglobal("CDLUA_COLOR_TAG");
+    color_tag = (int) lua_getnumber(cdlua_tag);
+    cdlua_tag = lua_getglobal("CDLUA_IMAGERGB_TAG");
+    imagergb_tag = (int) lua_getnumber(cdlua_tag);
+    cdlua_tag = lua_getglobal("CDLUA_IMAGERGBA_TAG");
+    imagergba_tag = (int) lua_getnumber(cdlua_tag);
+    cdlua_tag = lua_getglobal("CDLUA_PALETTE_TAG");
+    palette_tag = (int) lua_getnumber(cdlua_tag);
+    cdlua_tag = lua_getglobal("CDLUA_IMAGEMAP_TAG");
+    imagemap_tag = (int) lua_getnumber(cdlua_tag);
+    cdlua_tag = lua_getglobal("CDLUA_CHANNEL_TAG");
+    channel_tag = (int) lua_getnumber(cdlua_tag);
+  }
+  /* define IM own tags and fallbacks  */
+  else {
+    color_tag     = lua_newtag();
+    imagergb_tag  = lua_newtag();
+    imagergba_tag = lua_newtag();
+    imagemap_tag  = lua_newtag();
+    palette_tag   = lua_newtag();
+    channel_tag   = lua_newtag();
+
+    /* associate the fallbacks */
+    lua_pushcfunction(palettesettable_fb); lua_settagmethod(palette_tag, "settable");
+    lua_pushcfunction(channelsettable_fb); lua_settagmethod(channel_tag, "settable");
+    lua_pushcfunction(imagemapsettable_fb); lua_settagmethod(imagemap_tag, "settable");
+  
+    lua_pushcfunction(imagergbgettable_fb); lua_settagmethod(imagergb_tag, "gettable");
+    lua_pushcfunction(imagergbagettable_fb); lua_settagmethod(imagergba_tag, "gettable");
+    lua_pushcfunction(palettegettable_fb); lua_settagmethod(palette_tag, "gettable");
+    lua_pushcfunction(imagemapgettable_fb); lua_settagmethod(imagemap_tag, "gettable");
+    lua_pushcfunction(channelgettable_fb); lua_settagmethod(channel_tag, "gettable");
+
+    lua_pushcfunction(imagergbgc_fb); lua_settagmethod(imagergb_tag, "gc");
+    lua_pushcfunction(imagergbagc_fb); lua_settagmethod(imagergba_tag, "gc");
+    lua_pushcfunction(palettegc_fb); lua_settagmethod(palette_tag, "gc");
+    lua_pushcfunction(imagemapgc_fb); lua_settagmethod(imagemap_tag, "gc");
+  }
+
+  /* register used tags in global context for other libraries use */
+  lua_pushnumber(1.0f); lua_setglobal("IMLUA_INSTALLED");
+  lua_pushnumber( color_tag); lua_setglobal("IMLUA_COLOR_TAG");
+  lua_pushnumber( imagergb_tag); lua_setglobal("IMLUA_IMAGERGB_TAG");
+  lua_pushnumber( imagergba_tag); lua_setglobal("IMLUA_IMAGERGBA_TAG");
+  lua_pushnumber( imagemap_tag); lua_setglobal("IMLUA_IMAGEMAP_TAG");
+  lua_pushnumber( palette_tag); lua_setglobal("IMLUA_PALETTE_TAG");
+  lua_pushnumber( channel_tag); lua_setglobal("IMLUA_CHANNEL_TAG");
+
+  /* registered IM functions */
+  lua_register("imDecodeColor",         imlua_decodecolor);
+  lua_register("imEncodeColor",         imlua_encodecolor);
+  lua_register("imLoadRGB",             imlua_loadrgb);
+  lua_register("imLoadMap",             imlua_loadmap);
+  lua_register("imSaveRGB",             imlua_savergb);
+  lua_register("imSaveMap",             imlua_savemap);
+  lua_register("imFileFormat",          imlua_fileformat);
+  lua_register("imImageInfo",           imlua_imageinfo);
+  lua_register("imRGB2Map",             imlua_rgb2map);
+  lua_register("imMap2RGB",             imlua_map2rgb);
+  lua_register("imRGB2Gray",            imlua_rgb2gray);
+  lua_register("imMap2Gray",            imlua_map2gray);
+  lua_register("imVersion",             imlua_version);
+  lua_register("imResize",              imlua_resize);
+  lua_register("imStretch",             imlua_stretch);
+  
+  /* creation and destruction functions */
+  lua_register("imCreateImageRGB",      imlua_createimagergb);
+  lua_register("imCreateImageMap",      imlua_createimagemap);
+  lua_register("imCreatePalette",       imlua_createpalette);
+  lua_register("imKillImageRGB",        imlua_killimagergb);
+  lua_register("imKillImageMap",        imlua_killimagemap);
+  lua_register("imKillPalette",         imlua_killpalette);
+
+  /* im constants */
+  lua_pushnumber( IM_BMP); lua_setglobal("IM_BMP");
+  lua_pushnumber( IM_PCX); lua_setglobal("IM_PCX");
+  lua_pushnumber( IM_GIF); lua_setglobal("IM_GIF");
+  lua_pushnumber( IM_TIF); lua_setglobal("IM_TIF");
+  lua_pushnumber( IM_RAS); lua_setglobal("IM_RAS");
+  lua_pushnumber( IM_SGI); lua_setglobal("IM_SGI");
+  lua_pushnumber( IM_JPG); lua_setglobal("IM_JPG");
+  lua_pushnumber( IM_LED); lua_setglobal("IM_LED");
+  lua_pushnumber( IM_TGA); lua_setglobal("IM_TGA");
+
+  lua_pushnumber( 0); lua_setglobal("IM_NONE");
+  lua_pushnumber( 1); lua_setglobal("IM_DEFAULT");
+  lua_pushnumber( 2); lua_setglobal("IM_COMPRESSED");
+
+  lua_pushnumber( IM_RGB); lua_setglobal("IM_RGB");
+  lua_pushnumber( IM_MAP); lua_setglobal("IM_MAP");
+
+  lua_pushnumber( IM_ERR_NONE); lua_setglobal("IM_ERR_NONE");
+  lua_pushnumber( IM_ERR_OPEN); lua_setglobal("IM_ERR_OPEN");
+  lua_pushnumber( IM_ERR_READ); lua_setglobal("IM_ERR_READ");
+  lua_pushnumber( IM_ERR_WRITE); lua_setglobal("IM_ERR_WRITE");
+  lua_pushnumber( IM_ERR_FORMAT); lua_setglobal("IM_ERR_FORMAT");
+  lua_pushnumber( IM_ERR_TYPE); lua_setglobal("IM_ERR_TYPE");
+  lua_pushnumber( IM_ERR_COMP); lua_setglobal("IM_ERR_COMP");
+}