Tag and title images

cpdfcommand.ml

@@ -543,7 +543,8 @@ type args =
    mutable jbig2_lossy_threshold : float;
    mutable extract_stream_decompress : bool;
    mutable verify_single : string option;
-   mutable draw_struct_tree : bool}
+   mutable draw_struct_tree : bool;
+   mutable image_title : string option}
 
 let args =
   {op = None;
@@ -679,7 +680,8 @@ let args =
    jbig2_lossy_threshold = 0.85;
    extract_stream_decompress = false;
    verify_single = None;
-   draw_struct_tree = false}
+   draw_struct_tree = false;
+   image_title = None}
 
 (* Do not reset original_filename or cpdflin or was_encrypted or
 was_decrypted_with_owner or recrypt or producer or creator or path_to_* or
@@ -803,7 +805,8 @@ let reset_arguments () =
   args.extract_stream_decompress <- false;
   clear Cpdfdrawcontrol.fontpack_initialised;
   args.verify_single <- None;
-  args.draw_struct_tree <- false
+  args.draw_struct_tree <- false;
+  args.image_title <- None
 
 (* Prefer a) the one given with -cpdflin b) a local cpdflin, c) otherwise assume
 installed at a system place *)
@@ -2825,7 +2828,8 @@ let specs =
    ("-use", Arg.String Cpdfdrawcontrol.usexobj, " Use a saved sequence of graphics operators");
    ("-draw-jpeg", Arg.String Cpdfdrawcontrol.addjpeg, " Load a JPEG from file and name it");
    ("-draw-png", Arg.String Cpdfdrawcontrol.addpng, " Load a PNG from file and name it");
-   ("-image", Arg.String Cpdfdrawcontrol.addimage, " Draw an image which has already been loaded");
+   ("-image", Arg.String (fun s -> Cpdfdrawcontrol.addimage ?title:args.image_title s), " Draw an image which has already been loaded");
+   ("-image-title", Arg.String (fun s -> args.image_title <- Some s), " Give title for future images");
    ("-fill-opacity", Arg.Float Cpdfdrawcontrol.addopacity, " Set opacity");
    ("-stroke-opacity", Arg.Float Cpdfdrawcontrol.addsopacity, " Set stroke opacity");
    ("-bt", Arg.Unit Cpdfdrawcontrol.addbt, " Begin text");

cpdfdraw.ml

@@ -34,7 +34,7 @@ type drawops =
   | FormXObject of float * float * float * float * string * drawops list
   | Use of string
   | ImageXObject of string * Pdf.pdfobject
-  | Image of string
+  | Image of string * string option
   | NewPage
   | Opacity of float
   | SOpacity of float
@@ -202,7 +202,7 @@ let mcpage = ref ~-1
 type structdata =
   | StDataBeginTree of string
   | StDataEndTree
-  | StDataMCID of string * int
+  | StDataMCID of string * int * string option
   | StDataPage of int
 
 let structdata = ref []
@@ -251,10 +251,12 @@ let rec ops_of_drawop dryrun pdf endpage filename bates batespad num page = func
       let pdfname = try fst (Hashtbl.find (res ()).form_xobjects n) with _ -> error ("Form XObject not found: " ^ n) in
         (res ()).page_names <- pdfname::(res ()).page_names;
         [Pdfops.Op_Do pdfname]
-  | Image s ->
+  | Image (s, t) ->
+      let m = mcid () in
+        if not dryrun then structdata := StDataMCID ("/Figure", m, t)::!structdata;
       let pdfname = try fst (Hashtbl.find (res ()).images s) with _ -> error ("Image not found: " ^ s) in
         (res ()).page_names <- pdfname::(res ()).page_names;
-        [Pdfops.Op_Do pdfname]
+        [Pdfops.Op_BDC ("/Figure", Pdf.Dictionary ["/MCID", Pdf.Integer m]); Pdfops.Op_Do pdfname; Pdfops.Op_EMC]
   | ImageXObject (s, obj) ->
       Hashtbl.replace (res ()).images s (fresh_name "/I", Pdf.addobj pdf obj); 
       []
@@ -310,7 +312,7 @@ let rec ops_of_drawop dryrun pdf endpage filename bates batespad num page = func
         []
   | TextSection ops ->
       let m = mcid () in
-        if not dryrun then structdata := StDataMCID ("/P", m)::!structdata;
+        if not dryrun then structdata := StDataMCID ("/P", m, None)::!structdata;
         [Pdfops.Op_BDC ("/P", Pdf.Dictionary ["/MCID", Pdf.Integer m]);
          Pdfops.Op_BT]
         @ ops_of_drawops dryrun pdf endpage filename bates batespad num page ops @
@@ -445,7 +447,7 @@ let dryrun ~filename ~bates ~batespad range pdf chunks =
 
 type st =
    StMCID of int
- | StItem of {kind : string; pageobjnum : int; children : st list}
+ | StItem of {kind : string; pageobjnum : int; alt : string option; children : st list}
 
 (* Build a tree from the MCIDs and structure tree instructions gathered *)
 let make_structure_tree pdf items =
@@ -458,8 +460,8 @@ let make_structure_tree pdf items =
   in
   (* Process the items, making the st list tree data structure *)
   let process = function
-    | StDataMCID (n, mcid) ->
-        items_out =| StItem {kind = n; pageobjnum = unopt (lookup !pagenum pageobjnums); children = [StMCID mcid]}
+    | StDataMCID (n, mcid, alt) ->
+        items_out =| StItem {kind = n; alt; pageobjnum = unopt (lookup !pagenum pageobjnums); children = [StMCID mcid]}
     | StDataPage n ->
         pagenum := n
     | _ -> ()
@@ -481,14 +483,19 @@ let write_structure_tree pdf st =
   let struct_tree_root = Pdf.addobj pdf Pdf.Null in
   let items =
     map
-      (function StItem {kind; pageobjnum; children} ->
+      (function StItem {kind; pageobjnum; alt; children} ->
          let this_objnum = Pdf.addobj pdf Pdf.Null in
-         let this_obj = 
-             Pdf.Dictionary [("/S", Pdf.Name kind);
+         let alt =
+           match alt with
+           | Some s -> [("/Alt", Pdf.String s)]
+           | None -> []
+         in
+         let this_obj =
+             Pdf.Dictionary (alt @ [("/S", Pdf.Name kind);
                              ("/Pg", Pdf.Indirect pageobjnum);
                              ("/P", Pdf.Indirect struct_tree_root);
                              ("/K", Pdf.Array (map (function StMCID x -> add_parentmap pageobjnum this_objnum; Pdf.Integer x
-                                                    | _ -> assert false) children))]
+                                                    | _ -> assert false) children))])
          in
            Pdf.addobj_given_num pdf (this_objnum, this_obj);
            Pdf.Indirect this_objnum

cpdfdraw.mli

@@ -33,7 +33,7 @@ type drawops =
   | FormXObject of float * float * float * float * string * drawops list
   | Use of string
   | ImageXObject of string * Pdf.pdfobject
-  | Image of string
+  | Image of string * string option
   | NewPage
   | Opacity of float
   | SOpacity of float

cpdfdrawcontrol.ml

@@ -270,8 +270,8 @@ let addpng ?data n =
         let data = Pdfio.bytes_of_string (contents_of_file filename) in
           addop (Cpdfdraw.ImageXObject (name, fst (Cpdfimage.obj_of_png_data data)))
 
-let addimage s =
-  addop (Cpdfdraw.Image s)
+let addimage ?title s =
+  addop (Cpdfdraw.Image (s, title))
 
 let addnewpage s =
   addop Cpdfdraw.NewPage

cpdfdrawcontrol.mli

@@ -50,7 +50,7 @@ val endxobj : unit -> unit
 val usexobj : string -> unit
 val addjpeg : ?data:Pdfio.rawbytes -> string -> unit
 val addpng : ?data:Pdfio.rawbytes -> string -> unit
-val addimage : string -> unit
+val addimage : ?title:string -> string -> unit
 val addopacity : float -> unit
 val addsopacity : float -> unit
 val addbt : unit -> unit