modified color filter option to enable true gray for cis GL841 scanners

backend/genesys.c

@@ -102,6 +102,14 @@ static SANE_String_Const color_filter_list[] = {
   0
 };
 
+static SANE_String_Const cis_color_filter_list[] = {
+  SANE_I18N ("None"),
+  SANE_I18N ("Red"),
+  SANE_I18N ("Green"),
+  SANE_I18N ("Blue"),
+  0
+};
+
 static SANE_String_Const source_list[] = {
   SANE_I18N ("Flatbed"),
   SANE_I18N ("Transparency Adapter"),
@@ -5149,6 +5157,9 @@ calc_parameters (Genesys_Scanner * s)
   else
     s->dev->settings.color_filter = 1;
 
+  if (strcmp (color_filter, "None") == 0)
+    s->dev->settings.true_gray = 1;
+
   return status;
 }
 
@@ -5442,9 +5453,18 @@ init_options (Genesys_Scanner * s)
     ("When using gray or lineart this option selects the used color.");
   s->opt[OPT_COLOR_FILTER].type = SANE_TYPE_STRING;
   s->opt[OPT_COLOR_FILTER].constraint_type = SANE_CONSTRAINT_STRING_LIST;
-  s->opt[OPT_COLOR_FILTER].size = max_string_size (color_filter_list);
-  s->opt[OPT_COLOR_FILTER].constraint.string_list = color_filter_list;
-  s->val[OPT_COLOR_FILTER].s = strdup ("Green");
+  if(!model->is_cis)
+    {
+      s->opt[OPT_COLOR_FILTER].size = max_string_size (color_filter_list);
+      s->opt[OPT_COLOR_FILTER].constraint.string_list = color_filter_list;
+      s->val[OPT_COLOR_FILTER].s = strdup (s->opt[OPT_COLOR_FILTER].constraint.string_list[1]);
+    }
+  else
+    {
+      s->opt[OPT_COLOR_FILTER].size = max_string_size (cis_color_filter_list);
+      s->opt[OPT_COLOR_FILTER].constraint.string_list = cis_color_filter_list;
+      s->val[OPT_COLOR_FILTER].s = strdup (s->opt[OPT_COLOR_FILTER].constraint.string_list[0]);
+    }
 
   /* for GL646 cis scanners we're using true gray so ther is no filter */ 
   if (model->asic_type == GENESYS_GL646 && model->is_cis)

backend/genesys_gl841.c

@@ -2578,8 +2578,6 @@ gl841_init_optical_regs_scan(Genesys_Device * dev,
     }
     
     r->value &= ~(REG04_FILTER | REG04_AFEMOD);
-    /* we could make the color filter used an advanced option of the 
-       backend */
     if (channels == 1) {
 	switch (color_filter) {
 	    case 0:
@@ -4609,6 +4607,7 @@ static SANE_Status
 gl841_init_regs_for_scan (Genesys_Device * dev)
 {
   int channels;
+  int flags;
   int depth;
   float move;
   int move_dpi;
@@ -4678,6 +4677,17 @@ gl841_init_regs_for_scan (Genesys_Device * dev)
 
   start = (start * dev->sensor.optical_res) / MM_PER_INCH;
 
+  flags=0;
+
+  /* we aneable true gray for cis scanners only, and just when doing 
+   * scan since color calibration is OK for this mode
+   */
+  flags = 0;
+  if(dev->model->is_cis && dev->settings.true_gray)
+    {
+      flags |= OPTICAL_FLAG_ENABLE_LEDADD;
+    }
+
   status = gl841_init_scan_regs (dev,
 				 dev->reg,
 				 dev->settings.xres,
@@ -4689,7 +4699,7 @@ gl841_init_regs_for_scan (Genesys_Device * dev)
 				 depth,
 				 channels,
 				 dev->settings.color_filter,
-				 OPTICAL_FLAG_ENABLE_LEDADD);
+				 flags);
   
   if (status != SANE_STATUS_GOOD)
       return status;

backend/genesys_low.h

@@ -481,21 +481,23 @@ typedef struct
 {
   int scan_method;		/* todo: change >=2: Transparency, 0x88: negative film */
   int scan_mode;		/* todo: change 0,1 = lineart, halftone; 2 = gray, 3 = 3pass color, 4=single pass color */
-  int xres;			/* dpi */
-  int yres;			/* dpi */
+  int xres;			/**> horizontal dpi */
+  int yres;			/**> vertical dpi */
 
   double tl_x;			/* x start on scan table in mm */
   double tl_y;			/* y start on scan table in mm */
 
-  unsigned int lines;		/* number of lines at scan resolution */
-  unsigned int pixels;		/* number of pixels at scan resolution */
+  unsigned int lines;		/**> number of lines at scan resolution */
+  unsigned int pixels;		/**> number of pixels at scan resolution */
 
   unsigned int depth;/* bit depth of the scan */
 
   /* todo : remove these fields ? */
   int exposure_time;
 
-  unsigned int color_filter;	/* todo: check, may be make it an advanced option */
+  unsigned int color_filter;
+
+  int true_gray;		/**> true if scan is true gray, false if monochrome scan */
 
   /* BW threshold */
   int threshold;