cpdf-source/cpdfextracttext.ml

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2022-09-27 20:58:27 +02:00
open Pdfutil
let extract_page_text only_fontsize pdf _ page =
let text_extractor = ref None in
let right_font_size = ref false in
fold_left ( ^ ) ""
(map
(function
| Pdfops.Op_Tf (fontname, fontsize) ->
right_font_size :=
begin match only_fontsize with
Some x -> x = fontsize
| _ -> false
end;
let fontdict =
match Pdf.lookup_direct pdf "/Font" page.Pdfpage.resources with
| None -> raise (Pdf.PDFError "Missing /Font in text extraction")
| Some d ->
match Pdf.lookup_direct pdf fontname d with
| None -> raise (Pdf.PDFError "Missing font in text extraction")
| Some d -> d
in
text_extractor := Some (Pdftext.text_extractor_of_font pdf fontdict);
""
| Pdfops.Op_Tj text when !text_extractor <> None ->
if not !right_font_size then
""
else
Pdftext.utf8_of_codepoints
(Pdftext.codepoints_of_text (unopt !text_extractor) text)
| Pdfops.Op_TJ (Pdf.Array objs) when !text_extractor <> None ->
if not !right_font_size then
""
else
fold_left ( ^ ) ""
(option_map
(function
| Pdf.String text ->
Some
(Pdftext.utf8_of_codepoints
(Pdftext.codepoints_of_text (unopt !text_extractor) text))
| _ -> None)
objs)
| _ -> "")
(Pdfops.parse_operators pdf page.Pdfpage.resources page.Pdfpage.content))
(* For each page, extract all the ops with text in them, and concatenate it all together *)
let extract_text extract_text_font_size pdf range =
fold_left (fun x y -> x ^ (if x <> "" && y <> "" then "\n" else "") ^ y) ""
(Cpdfpage.map_pages (extract_page_text extract_text_font_size pdf) pdf range)