Refactoring of image processing

cpdfcommand.ml

@@ -585,7 +585,7 @@ let args =
    retain_numbering = false;
    remove_duplicate_fonts = false;
    remove_duplicate_streams = false;
-   encoding = Cpdfmetadata.UTF;
+   encoding = Cpdfmetadata.UTF8;
    scale = 1.;
    copyfontpage = 1;
    copyfontname = None;
@@ -713,7 +713,7 @@ let reset_arguments () =
   args.retain_numbering <- false;
   args.remove_duplicate_fonts <- false;
   args.remove_duplicate_streams <- false;
-  args.encoding <- Cpdfmetadata.UTF;
+  args.encoding <- Cpdfmetadata.UTF8;
   args.scale <- 1.;
   args.copyfontpage <- 1;
   args.copyfontname <- None;

cpdfimage.ml

@@ -551,25 +551,43 @@ let suitable_num pdf dict =
   | Some (Pdf.Array (Pdf.Name "/Separation"::_)) -> ~-1
   | _ -> 0
 
-let lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~qlossless ~path_to_convert s dict reference =
+
+
+let lossless_out pdf ~pixel_threshold ~length_threshold extension s dict reference =
   let bpc = Pdf.lookup_direct pdf "/BitsPerComponent" dict in
   let components = suitable_num pdf dict in
   match components, bpc with
   | (1 | 3 | 4 | -1), Some (Pdf.Integer 8) ->
       let w = match Pdf.lookup_direct pdf "/Width" dict with Some (Pdf.Integer i) -> i | _ -> error "bad width" in
       let h = match Pdf.lookup_direct pdf "/Height" dict with Some (Pdf.Integer i) -> i | _ -> error "bad height" in
-      if w * h < pixel_threshold then () else
+      if w * h < pixel_threshold then None else
       let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
-      if size < length_threshold then () else
+      if size < length_threshold then None else
+      begin
         Pdfcodec.decode_pdfstream_until_unknown pdf s;
-      begin match Pdf.lookup_direct pdf "/Filter" (fst !reference) with Some _ -> () | None ->
+        match Pdf.lookup_direct pdf "/Filter" (fst !reference) with Some _ -> None | None ->
         let out = Filename.temp_file "cpdf" "convertin" ^ (if suitable_num pdf dict < 4 then ".pnm" else ".cmyk") in
-        let out2 = Filename.temp_file "cpdf" "convertout" ^ ".jpg" in
+        let out2 = Filename.temp_file "cpdf" "convertout" ^ extension in
         let fh = open_out_bin out in
         let data = match s with Pdf.Stream {contents = _, Pdf.Got d} -> d | _ -> assert false in
         (if components = 3 then pnm_to_channel_24 else
          if components = 4 then cmyk_to_channel_32 else pnm_to_channel_8) fh w h data;
         close_out fh;
+        Some (out, out2, size, components, w, h)
+      end
+  | colspace, bpc ->
+    (*let colspace = Pdf.lookup_direct pdf "/ColorSpace" dict in
+    let colspace, bpc, filter = 
+      (match colspace with None -> "none" | Some x -> Pdfwrite.string_of_pdf x),
+      (match bpc with None -> "none" | Some x -> Pdfwrite.string_of_pdf x),
+      (match Pdf.lookup_direct pdf "/Filter" dict with None -> "none" | Some x -> Pdfwrite.string_of_pdf x)
+    in
+      print_string (Pdfwrite.string_of_pdf dict);
+      print_string (Printf.sprintf "%s (%s) [%s]\n" colspace bpc filter);*)
+      None (* an image we cannot or do not handle *)
+
+let lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~qlossless ~path_to_convert s dict reference =
+  match lossless_out pdf ~pixel_threshold ~length_threshold ".jpg" s dict reference with None -> () | Some (out, out2, size, components, w, h) ->
   let retcode =
     let command = 
       (Filename.quote_command path_to_convert
@@ -598,17 +616,37 @@ let lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshol
     end;
   Sys.remove out;
   Sys.remove out2
-      end
-  | colspace, bpc ->
-    (*let colspace = Pdf.lookup_direct pdf "/ColorSpace" dict in
-    let colspace, bpc, filter = 
-      (match colspace with None -> "none" | Some x -> Pdfwrite.string_of_pdf x),
-      (match bpc with None -> "none" | Some x -> Pdfwrite.string_of_pdf x),
-      (match Pdf.lookup_direct pdf "/Filter" dict with None -> "none" | Some x -> Pdfwrite.string_of_pdf x)
+
+let lossless_resample pdf ~pixel_threshold ~length_threshold ~percentage_threshold~interpolate ~path_to_convert s dict reference =
+  match lossless_out pdf ~pixel_threshold ~length_threshold ".png" s dict reference with None -> () | Some (out, out2, size, components, w, h) ->
+  let retcode =
+    let command = 
+      (Filename.quote_command path_to_convert
+        ((if components = 4 then ["-depth"; "8"; "-size"; string_of_int w ^ "x" ^ string_of_int h] else []) @
+        [out] @
+        (if components = 1 then ["-colorspace"; "Gray"] else if components = 4 then ["-colorspace"; "CMYK"] else []) @
+        [out2]))
     in
-      print_string (Pdfwrite.string_of_pdf dict);
-      print_string (Printf.sprintf "%s (%s) [%s]\n" colspace bpc filter);*)
-      () (* an image we cannot or do not handle *)
+      (*Printf.printf "%S\n" command;*) Sys.command command
+  in
+  if retcode = 0 then
+    begin
+      let result = open_in_bin out2 in
+      let newsize = in_channel_length result in
+      if newsize < size then
+        begin
+          if !debug_image_processing then Printf.printf "Lossless to JPEG %i -> %i\n%!" size newsize;
+          reference :=
+            (Pdf.add_dict_entry
+              (Pdf.add_dict_entry dict "/Length" (Pdf.Integer newsize))
+               "/Filter"
+               (Pdf.Name "/DCTDecode")),
+            Pdf.Got (Pdfio.bytes_of_input_channel result)
+        end;
+        close_in result
+    end;
+  Sys.remove out;
+  Sys.remove out2
 
 let recompress_1bpp_jbig2_lossless ~pixel_threshold ~length_threshold ~path_to_jbig2enc pdf s dict reference =
   let w = match Pdf.lookup_direct pdf "/Width" dict with Some (Pdf.Integer i) -> i | _ -> error "bad width" in