gimp_image_convert_rgb ()

gboolean
gimp_image_convert_rgb (gint32 image_ID);

gimp_image_convert_grayscale ()

gboolean
gimp_image_convert_grayscale (gint32 image_ID);

gimp_image_convert_indexed ()

gboolean
gimp_image_convert_indexed (gint32 image_ID,
                            GimpConvertDitherType dither_type,
                            GimpConvertPaletteType palette_type,
                            gint num_cols,
                            gboolean alpha_dither,
                            gboolean remove_unused,
                            const gchar *palette);

gimp_image_convert_set_dither_matrix ()

gboolean
gimp_image_convert_set_dither_matrix (gint width,
                                      gint height,
                                      gint matrix_length,
                                      const guint8 *matrix);

Since: GIMP 2.4