diff --git a/src/global.h b/src/global.h
index 0bf4d00f..0e23822f 100644
--- a/src/global.h
+++ b/src/global.h
@@ -699,7 +699,7 @@ GFX2_GLOBAL Func_gradient Gradient_function;
 /// either ::Pixel (if the gradient must be drawn on menus only)
 /// or ::Display_pixel (if the gradient must be drawn on the image)
 GFX2_GLOBAL Func_pixel Gradient_pixel;
-/// Index in ::T_Page::Gradient_array of the currently selected gradient.
+/// Index in ::T_Page::Gradients of the currently selected gradient.
 GFX2_GLOBAL byte Current_gradient;
 /// Boolean, true when the color cycling is active.
 GFX2_GLOBAL byte Cycling_mode;
diff --git a/src/loadsave.c b/src/loadsave.c
index d2738916..063b8ecf 100644
--- a/src/loadsave.c
+++ b/src/loadsave.c
@@ -1108,6 +1108,7 @@ void Load_SDL_Image(T_IO_Context *context)
 
 ///
 /// Load an arbitrary SDL_Surface.
+/// @param full_name Full (absolute) path of the file to load.
 /// @param gradients Pass the address of a target T_Gradient_array if you want the gradients, NULL otherwise
 SDL_Surface * Load_surface(char *full_name, T_Gradient_array *gradients)
 {
diff --git a/src/op_c.c b/src/op_c.c
index fd785223..b3cab93f 100644
--- a/src/op_c.c
+++ b/src/op_c.c
@@ -1027,7 +1027,19 @@ void GS_Generate(T_Gradient_set * ds,T_Cluster_set * cs)
 
 
 /// Compute best palette for given picture.
-/// @param size in pixels
+///
+/// The picture is first depth-reduced to the given
+/// r,g,b resolution, then the median cut algorithm is used to find 256 colors which are suitable
+/// for the given picture.
+///
+/// @returns a conversion tree to be used for converting the picture to indexed with the generated palette (with or without dithering).
+///
+/// @param image The true-color image for which the palette needs to be optimized
+/// @param size in pixels (number of pixels, the height/width doesn't matter)
+/// @param palette pointer to the space where the palette will be stored (256 entries at most)
+/// @param r Resolution for red
+/// @param g Resolution for green
+/// @param b Resolution for blue
 CT_Tree* Optimize_palette(T_Bitmap24B image, int size,
   T_Components * palette, int r, int g, int b)
 {	
diff --git a/src/pages.h b/src/pages.h
index f02ea4a9..47dcdff1 100644
--- a/src/pages.h
+++ b/src/pages.h
@@ -44,7 +44,7 @@ extern byte * FX_feedback_screen;
 extern T_Bitmap Main_visible_image;
 /// The pixels of visible layers, flattened copy, used for no-feedback effects.
 extern T_Bitmap Main_visible_image_backup;
-/// The index of visible pixels from ::Visible image. Points to the right layer.
+/// The index of visible pixels from ::Main_visible_image. Points to the right layer.
 extern T_Bitmap Main_visible_image_depth_buffer;
 /// The pixels of visible layers for the spare page, flattened copy.
 extern T_Bitmap Spare_visible_image;