cpdf-source/cpdfimage.ml
2024-03-22 15:33:08 +00:00

966 lines
45 KiB
OCaml

open Pdfutil
open Pdfio
open Cpdferror
let debug_image_processing = ref false
let complain_jbig2enc path =
if path = "" then error "Specify jbig2enc location with -jbig2enc"
let complain_convert path =
if path = "" then error "Specify magick location with -im"
let remove x =
try (*Printf.printf "%s\n" x;*) Sys.remove x with _ -> ()
let pnm_white ch = output_char ch ' '
let pnm_newline ch = output_char ch '\n'
let pnm_output_string = Stdlib.output_string
let pnm_header ch w h =
pnm_white ch;
pnm_output_string ch (string_of_int w);
pnm_white ch;
pnm_output_string ch (string_of_int h);
pnm_white ch
let pnm_to_channel_24 ch w h s =
pnm_output_string ch "P6";
pnm_header ch w h;
pnm_output_string ch "255";
pnm_newline ch;
bytes_to_output_channel ch s
let pnm_to_channel_8 ch w h s =
pnm_output_string ch "P5";
pnm_header ch w h;
pnm_output_string ch "255";
pnm_newline ch;
bytes_to_output_channel ch s
let pnm_to_channel_1_inverted ch w h s =
pnm_output_string ch "P4";
pnm_header ch w h;
pnm_newline ch;
let inverted = Pdfio.copybytes s in
Pdfio.bytes_selfmap lnot inverted;
bytes_to_output_channel ch inverted
let cmyk_to_channel_32 ch w h s =
let inverted = Pdfio.copybytes s in
Pdfio.bytes_selfmap (fun x -> 255 - x) inverted;
bytes_to_output_channel ch inverted
let jbig2_serial = ref 0
let jbig2_globals = null_hash ()
let write_stream name stream =
let fh = open_out_bin name in
Pdfio.bytes_to_output_channel fh stream;
close_out fh
let write_image ~raw ?path_to_p2p ?path_to_im pdf resources name image =
match Pdfimage.get_image_24bpp pdf resources image with
| Pdfimage.JPEG (stream, _) -> write_stream (name ^ ".jpg") stream
| Pdfimage.JPEG2000 (stream, _) -> write_stream (name ^ ".jpx") stream
| Pdfimage.JBIG2 (stream, _, global) ->
begin match global with
| None ->
(*Printf.printf "JBIG2: No global, writing plain\n";*)
write_stream (name ^ ".jbig2") stream
| Some g ->
(*Printf.printf "JBIG2: there is a global\n";*)
let go () =
let serial, _ = Hashtbl.find jbig2_globals g in
write_stream (name ^ ".jbig2__" ^ string_of_int serial) stream
in
try go () with Not_found ->
jbig2_serial += 1;
let globaldata =
let obj = Pdf.lookup_obj pdf g in
Pdfcodec.decode_pdfstream_until_unknown pdf obj;
match obj with | Pdf.Stream {contents = (_, Got b)} -> Some b | _ -> None
in
match globaldata with
| Some d ->
Hashtbl.add jbig2_globals g (!jbig2_serial, d);
let filename = Filename.concat (Filename.dirname name) (string_of_int !jbig2_serial ^ ".jbig2global") in
write_stream filename d;
go ()
| None ->
Pdfe.log "Could not extract JBIG2Globals. Skipping this image."
end
| Pdfimage.Raw (w, h, Pdfimage.BPP24, stream) ->
let pnm = name ^ ".pnm" in
let png = name ^ ".png" in
let fh = open_out_bin pnm in
pnm_to_channel_24 fh w h stream;
close_out fh;
begin match path_to_p2p with
| None ->
begin match path_to_im with
None ->
if not raw then Pdfe.log "Neither pnm2png nor imagemagick found. Specify with -p2p or -im\n"
| Some path_to_im ->
begin match
Sys.command (Filename.quote_command path_to_im [pnm; png])
with
0 -> remove pnm
| _ ->
Pdfe.log "Call to imagemagick failed: did you specify -p2p or -im correctly?\n";
remove pnm
end
end
| Some path_to_p2p ->
begin match
Sys.command (Filename.quote_command path_to_p2p ~stdout:png ["-gamma"; "0.45"; "-quiet"; pnm])
with
| 0 -> remove pnm
| _ ->
Pdfe.log "Call to pnmtopng failed: did you specify -p2p correctly?\n";
remove pnm
end
end
| _ ->
Pdfe.log (Printf.sprintf "Unsupported image type when extracting image %s " name)
let written = ref []
let extract_images_inner ~raw ?path_to_p2p ?path_to_im encoding serial pdf resources stem pnum images =
let names = map
(fun _ ->
Cpdfbookmarks.name_of_spec
encoding [] pdf 0 (stem ^ "-p" ^ string_of_int pnum)
(let r = !serial in serial := !serial + 1; r) "" 0 0) (indx images)
in
iter2 (write_image ~raw ?path_to_p2p ?path_to_im pdf resources) names images
let extract_images_form_xobject ~raw ?path_to_p2p ?path_to_im encoding dedup dedup_per_page pdf serial stem pnum form =
let resources =
match Pdf.lookup_direct pdf "/Resources" form with
Some (Pdf.Dictionary d) -> Pdf.Dictionary d
| _ -> Pdf.Dictionary []
in
let images =
let xobjects =
match Pdf.lookup_direct pdf "/XObject" resources with
| Some (Pdf.Dictionary elts) -> map snd elts
| _ -> []
in
(* Remove any already in !written. Add any remaining to !written, if !args.dedup or !args.dedup_page *)
let images = keep (fun o -> Pdf.lookup_direct pdf "/Subtype" o = Some (Pdf.Name "/Image")) xobjects in
let already_written, images = List.partition (function Pdf.Indirect n -> mem n !written | _ -> false) images in
if dedup || dedup_per_page then
written := (option_map (function Pdf.Indirect n -> Some n | _ -> None) images) @ !written;
images
in
extract_images_inner ~raw ?path_to_p2p ?path_to_im encoding serial pdf resources stem pnum images
let extract_images ?(raw=false) ?path_to_p2p ?path_to_im encoding dedup dedup_per_page pdf range stem =
Hashtbl.clear jbig2_globals;
jbig2_serial := 0;
if dedup || dedup_per_page then written := [];
let pdf_pages = Pdfpage.pages_of_pagetree pdf in
let pages =
option_map
(function (i, pdf_pages) -> if mem i range then Some pdf_pages else None)
(combine (indx pdf_pages) pdf_pages)
in
let serial = ref 0 in
iter2
(fun page pnum ->
if dedup_per_page then written := [];
let xobjects =
match Pdf.lookup_direct pdf "/XObject" page.Pdfpage.resources with
| Some (Pdf.Dictionary elts) -> map snd elts
| _ -> []
in
let images = keep (fun o -> Pdf.lookup_direct pdf "/Subtype" o = Some (Pdf.Name "/Image")) xobjects in
let already_written, images = List.partition (function Pdf.Indirect n -> mem n !written | _ -> false) images in
if dedup || dedup_per_page then
written := (option_map (function Pdf.Indirect n -> Some n | _ -> None) images) @ !written;
let forms = keep (fun o -> Pdf.lookup_direct pdf "/Subtype" o = Some (Pdf.Name "/Form")) xobjects in
extract_images_inner ~raw ?path_to_p2p ?path_to_im encoding serial pdf page.Pdfpage.resources stem pnum images;
iter (extract_images_form_xobject ~raw ?path_to_p2p ?path_to_im encoding dedup dedup_per_page pdf serial stem pnum) forms)
pages
(indx pages)
(* Image resolution *)
type xobj =
| Image of int * int (* width, height *)
| Form of Pdftransform.transform_matrix * Pdf.pdfobject * Pdf.pdfobject (* Will add actual data later. *)
let image_results = ref []
let rec image_resolution_page pdf page pagenum dpi images =
try
let pageops = Pdfops.parse_operators pdf page.Pdfpage.resources page.Pdfpage.content
and transform = ref [ref Pdftransform.i_matrix] in
iter
(function
| Pdfops.Op_cm matrix ->
begin match !transform with
| [] -> raise (Failure "no transform")
| _ -> (hd !transform) := Pdftransform.matrix_compose !(hd !transform) matrix
end
| Pdfops.Op_Do xobject ->
let trans (x, y) =
match !transform with
| [] -> raise (Failure "no transform")
| _ -> Pdftransform.transform_matrix !(hd !transform) (x, y)
in
let o = trans (0., 0.)
and x = trans (1., 0.)
and y = trans (0., 1.)
in
(*i Printf.printf "o = %f, %f, x = %f, %f, y = %f, %f\n" (fst o) (snd o) (fst x) (snd x) (fst y) (snd y); i*)
let rec lookup_image k = function
| [] -> assert false
| (_, a, _, _) as h::_ when a = k -> h
| _::t -> lookup_image k t
in
begin match lookup_image xobject images with
| (pagenum, name, Form (xobj_matrix, content, resources), objnum) ->
let content =
(* Add in matrix etc. *)
let total_matrix = Pdftransform.matrix_compose xobj_matrix !(hd !transform) in
let ops =
Pdfops.Op_cm total_matrix::
Pdfops.parse_operators pdf resources [content]
in
Pdfops.stream_of_ops ops
in
let page =
{Pdfpage.content = [content];
Pdfpage.mediabox = Pdfpage.rectangle_of_paper Pdfpaper.a4;
Pdfpage.resources = resources;
Pdfpage.rotate = Pdfpage.Rotate0;
Pdfpage.rest = Pdf.Dictionary []}
in
let newpdf = Pdfpage.change_pages false pdf [page] in
image_resolution newpdf [pagenum] dpi
| (pagenum, name, Image (w, h), objnum) ->
let lx = Pdfunits.inches (distance_between o x) Pdfunits.PdfPoint in
let ly = Pdfunits.inches (distance_between o y) Pdfunits.PdfPoint in
let wdpi = float w /. lx
and hdpi = float h /. ly in
image_results := (pagenum, xobject, w, h, wdpi, hdpi, objnum)::!image_results
(*Printf.printf "%i, %s, %i, %i, %f, %f\n" pagenum xobject w h wdpi hdpi*)
(*i else
Printf.printf "S %i, %s, %i, %i, %f, %f\n" pagenum xobject (int_of_float w) (int_of_float h) wdpi hdpi i*)
end
| Pdfops.Op_q ->
begin match !transform with
| [] -> raise (Failure "Unbalanced q/Q ops")
| h::t ->
let h' = ref Pdftransform.i_matrix in
h' := !h;
transform := h'::h::t
end
| Pdfops.Op_Q ->
begin match !transform with
| [] -> raise (Failure "Unbalanced q/Q ops")
| _ -> transform := tl !transform
end
| _ -> ())
pageops
with
e -> Printf.printf "Error %s\n" (Printexc.to_string e); flprint "\n"
and image_resolution pdf range dpi =
let images = ref [] in
Cpdfpage.iter_pages
(fun pagenum page ->
(* 1. Get all image names and their native resolutions from resources as string * int * int *)
match Pdf.lookup_direct pdf "/XObject" page.Pdfpage.resources with
| Some (Pdf.Dictionary xobjects) ->
iter
(function (name, xobject) ->
let objnum = match xobject with Pdf.Indirect i -> i | _ -> 0 in
match Pdf.lookup_direct pdf "/Subtype" xobject with
| Some (Pdf.Name "/Image") ->
let width =
match Pdf.lookup_direct pdf "/Width" xobject with
| Some x -> Pdf.getnum pdf x
| None -> 1.
and height =
match Pdf.lookup_direct pdf "/Height" xobject with
| Some x -> Pdf.getnum pdf x
| None -> 1.
in
images := (pagenum, name, Image (int_of_float width, int_of_float height), objnum)::!images
| Some (Pdf.Name "/Form") ->
let resources =
match Pdf.lookup_direct pdf "/Resources" xobject with
| None -> page.Pdfpage.resources (* Inherit from page or form above. *)
| Some r -> r
and contents =
xobject
and matrix =
match Pdf.lookup_direct pdf "/Matrix" xobject with
| Some (Pdf.Array [a; b; c; d; e; f]) ->
{Pdftransform.a = Pdf.getnum pdf a; Pdftransform.b = Pdf.getnum pdf b; Pdftransform.c = Pdf.getnum pdf c;
Pdftransform.d = Pdf.getnum pdf d; Pdftransform.e = Pdf.getnum pdf e; Pdftransform.f = Pdf.getnum pdf f}
| _ -> Pdftransform.i_matrix
in
images := (pagenum, name, Form (matrix, contents, resources), objnum)::!images
| _ -> ()
)
xobjects
| _ -> ())
pdf
range;
(* Now, split into differing pages, and call [image_resolution_page] on each one *)
let pagesplits =
map
(function (a, _, _, _)::_ as ls -> (a, ls) | _ -> assert false)
(collate (fun (a, _, _, _) (b, _, _, _) -> compare a b) (rev !images))
and pages =
Pdfpage.pages_of_pagetree pdf
in
iter
(function (pagenum, images) ->
let page = select pagenum pages in
image_resolution_page pdf page pagenum dpi images)
pagesplits
let image_resolution pdf range dpi =
image_results := [];
image_resolution pdf range dpi;
rev !image_results
let image_resolution_json pdf range dpi =
let images = image_resolution pdf range dpi in
Pdfio.bytes_of_string
(Cpdfyojson.Safe.pretty_to_string
(`List (map (fun (pagenum, xobject, w, h, wdpi, hdpi, objnum) ->
`Assoc [("Object", `Int objnum); ("Page", `Int pagenum); ("XObject", `String xobject);
("W", `Int w); ("H", `Int h); ("Xdpi", `Float wdpi); ("Ydpi", `Float hdpi)]) images)))
(* All the images in file referenced at least once from the given range of pages. *)
let images pdf range =
let images = null_hash () in
let formnums = null_hash () in
let rec process_xobject resources pagenum page (name, xobject) =
match Pdf.lookup_direct pdf "/Subtype" xobject with
| Some (Pdf.Name "/Image") ->
begin match xobject with
| Pdf.Indirect i ->
begin match Hashtbl.find images i with
| (pagenums, n, w, h, s, bpc, cs, f) ->
Hashtbl.replace images i (pagenum::pagenums, n, w, h, s, bpc, cs, f)
| exception Not_found ->
let width =
match Pdf.lookup_direct pdf "/Width" xobject with
| Some x -> Pdf.getnum pdf x
| None -> 1.
and height =
match Pdf.lookup_direct pdf "/Height" xobject with
| Some x -> Pdf.getnum pdf x
| None -> 1.
and size =
match Pdf.lookup_direct pdf "/Length" xobject with
| Some (Pdf.Integer x) -> x
| _ -> 0
and bpc =
match Pdf.lookup_direct pdf "/BitsPerComponent" xobject with
| Some (Pdf.Integer x) -> Some x
| _ -> None
and colourspace =
match Pdf.lookup_direct pdf "/ColorSpace" xobject with
| Some x -> Some (Pdfspace.string_of_colourspace (Pdfspace.read_colourspace pdf resources x))
| None -> None
and filter =
match Pdf.lookup_direct pdf "/Filter" xobject with
| Some (Pdf.Array [x]) | Some x -> Some (Pdfwrite.string_of_pdf x)
| None -> None
in
Hashtbl.replace images i ([pagenum], name, int_of_float width, int_of_float height, size, bpc, colourspace, filter)
end
| _ -> ()
end
| Some (Pdf.Name "/Form") ->
begin match xobject with
| Pdf.Indirect i ->
begin match Hashtbl.find formnums i with
| () -> ()
| exception Not_found ->
Hashtbl.add formnums i ();
begin match Pdf.lookup_direct pdf "/Resources" xobject with
| Some r ->
begin match Pdf.lookup_direct pdf "/XObject" r with
| Some (Pdf.Dictionary xobjects) -> iter (process_xobject r pagenum page) xobjects
| _ -> ()
end
| None -> ()
end
end
| _ -> ()
end
| _ -> ()
in
Cpdfpage.iter_pages
(fun pagenum page ->
match Pdf.lookup_direct pdf "/XObject" page.Pdfpage.resources with
| Some (Pdf.Dictionary xobjects) ->
iter (process_xobject page.Pdfpage.resources pagenum page) xobjects
| _ -> ())
pdf
range;
let images = list_of_hashtbl images in
let images = map (fun (i, (pnums, n, w, h, s, bpc, c, filter)) -> (i, (setify (sort compare pnums), n, w, h, s, bpc, c, filter))) images in
let images = sort (fun (_, (pnums, _, _, _, _, _, _, _)) (_, (pnums', _, _, _, _, _, _, _)) -> compare (hd pnums) (hd pnums')) images in
`List
(map
(fun (i, (pnums, n, w, h, size, bpc, cs, filter)) ->
`Assoc [("Object", `Int i);
("Pages", `List (map (fun x -> `Int x) pnums));
("Name", `String n);
("Width", `Int w);
("Height", `Int h);
("Bytes", `Int size);
("BitsPerComponent", match bpc with None -> `Null | Some bpc -> `Int bpc);
("Colourspace", match cs with None -> `Null | Some s -> `String s);
("Filter", match filter with None -> `Null | Some s -> `String s)])
images)
let obj_of_jpeg_data data =
let w, h = Cpdfjpeg.jpeg_dimensions data in
let d =
["/Length", Pdf.Integer (Pdfio.bytes_size data);
"/Filter", Pdf.Name "/DCTDecode";
"/BitsPerComponent", Pdf.Integer 8;
"/ColorSpace", Pdf.Name "/DeviceRGB";
"/Subtype", Pdf.Name "/Image";
"/Width", Pdf.Integer w;
"/Height", Pdf.Integer h]
in
Pdf.Stream {contents = (Pdf.Dictionary d, Pdf.Got data)}, []
let obj_of_png_data data =
let png = Cpdfpng.read_png (Pdfio.input_of_bytes data) in
let d =
["/Length", Pdf.Integer (Pdfio.bytes_size png.idat);
"/Filter", Pdf.Name "/FlateDecode";
"/Subtype", Pdf.Name "/Image";
"/BitsPerComponent", Pdf.Integer png.bitdepth;
"/ColorSpace", Pdf.Name (match png.colortype with 0 -> "/DeviceGray" | 2 -> "/DeviceRGB" | _ -> error "obj_of_png_data 1");
"/DecodeParms", Pdf.Dictionary
["/BitsPerComponent", Pdf.Integer png.bitdepth;
"/Colors", Pdf.Integer (match png.colortype with 0 -> 1 | 2 -> 3 | _ -> error "obj_of_png_data 2");
"/Columns", Pdf.Integer png.width;
"/Predictor", Pdf.Integer 15];
"/Width", Pdf.Integer png.width;
"/Height", Pdf.Integer png.height]
in
Pdf.Stream {contents = (Pdf.Dictionary d, Pdf.Got png.idat)}, []
let obj_of_jpeg2000_data data =
let w, h = Cpdfjpeg2000.jpeg2000_dimensions data in
let d =
["/Length", Pdf.Integer (Pdfio.bytes_size data);
"/Filter", Pdf.Name "/JPXDecode";
"/Subtype", Pdf.Name "/Image";
"/Width", Pdf.Integer w;
"/Height", Pdf.Integer h]
in
Pdf.Stream {contents = (Pdf.Dictionary d, Pdf.Got data)}, []
let jbig2_dimensions data =
(bget data 11 * 256 * 256 * 256 + bget data 12 * 256 * 256 + bget data 13 * 256 + bget data 14,
bget data 15 * 256 * 256 * 256 + bget data 16 * 256 * 256 + bget data 17 * 256 + bget data 18)
let obj_of_jbig2_data ?global data =
let d, extra =
let decodeparms, extra =
match global with
| Some data ->
[("/DecodeParms", Pdf.Dictionary [("/JBIG2Globals", Pdf.Indirect 10000)])],
[(10000, Pdf.Stream {contents = (Pdf.Dictionary [("/Length", Pdf.Integer (bytes_size data))], Pdf.Got data)})]
| None ->
[], []
in
let w, h = jbig2_dimensions data in
[("/Length", Pdf.Integer (Pdfio.bytes_size data));
("/Filter", Pdf.Name "/JBIG2Decode");
("/Subtype", Pdf.Name "/Image");
("/BitsPerComponent", Pdf.Integer 1);
("/ColorSpace", Pdf.Name "/DeviceGray");
("/Width", Pdf.Integer w);
("/Height", Pdf.Integer h)]
@ decodeparms, extra
in
Pdf.Stream {contents = (Pdf.Dictionary d, Pdf.Got data)}, extra
let image_of_input fobj i =
let pdf = Pdf.empty () in
let data = Pdfio.bytes_of_input i 0 i.Pdfio.in_channel_length in
let obj, extras = fobj () data in
iter (Pdf.addobj_given_num pdf) extras;
let w = match Pdf.lookup_direct pdf "/Width" obj with Some x -> Pdf.getnum pdf x | _ -> assert false in
let h = match Pdf.lookup_direct pdf "/Height" obj with Some x -> Pdf.getnum pdf x | _ -> assert false in
let page =
{Pdfpage.content =
[Pdfops.stream_of_ops
[Pdfops.Op_cm (Pdftransform.matrix_of_transform [Pdftransform.Translate (0., 0.);
Pdftransform.Scale ((0., 0.), w, h)]);
Pdfops.Op_Do "/I0"]];
Pdfpage.mediabox = Pdf.Array [Pdf.Real 0.; Pdf.Real 0.; Pdf.Real w; Pdf.Real h];
Pdfpage.resources =
Pdf.Dictionary
["/XObject", Pdf.Dictionary ["/I0", Pdf.Indirect (Pdf.addobj pdf obj)]];
Pdfpage.rotate = Pdfpage.Rotate0;
Pdfpage.rest = Pdf.Dictionary []}
in
let pdf, pageroot = Pdfpage.add_pagetree [page] pdf in
Pdfpage.add_root pageroot [] pdf
let jpeg_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~q ~path_to_convert s dict reference =
if q < 0. || q > 100. then error "Out of range quality";
complain_convert path_to_convert;
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 (if !debug_image_processing then Printf.printf "pixel threshold not met\n%!") else
Pdf.getstream s;
let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
if size < length_threshold then (if !debug_image_processing then Printf.printf "length threshold not met\n%!") else
let out = Filename.temp_file "cpdf" "convertin.jpg" in
let out2 = Filename.temp_file "cpdf" "convertout.jpg" in
let fh = open_out_bin out in
begin match s with Pdf.Stream {contents = _, Pdf.Got d} -> Pdfio.bytes_to_output_channel fh d | _ -> () end;
close_out fh;
let retcode =
let command =
(Filename.quote_command path_to_convert [out; "-quality"; string_of_float q ^ "%"; out2])
in
(*Printf.printf "%S\n" command;*) Sys.command command
in
if retcode = 0 then
begin
try
let result = open_in_bin out2 in
let newsize = in_channel_length result in
let perc_ok = float newsize /. float size < percentage_threshold /. 100. in
if newsize < size && perc_ok then
begin
if !debug_image_processing then Printf.printf "JPEG to JPEG %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
reference := Pdf.add_dict_entry dict "/Length" (Pdf.Integer newsize), Pdf.Got (Pdfio.bytes_of_input_channel result)
end
else
begin
if !debug_image_processing then Printf.printf "no size reduction\n%!"
end;
close_in result
with _ ->
remove out;
remove out2
end
else
begin Printf.printf "external process failed\n%!" end;
remove out;
remove out2
let suitable_num pdf dict =
match Pdf.lookup_direct pdf "/ColorSpace" dict with
| Some (Pdf.Name ("/DeviceRGB" | "/CalRGB")) -> 3
| Some (Pdf.Name ("/DeviceGray" | "/CalGray")) -> 1
| Some (Pdf.Name "/DeviceCMYK") -> 4
| Some (Pdf.Array [Pdf.Name "/Lab"; _]) -> 3
| Some (Pdf.Array [Pdf.Name "/ICCBased"; stream]) ->
begin match Pdf.lookup_direct pdf "/N" stream with
| Some (Pdf.Integer 3) -> 3
| Some (Pdf.Integer 1) -> 1
| Some (Pdf.Integer 4) -> 4
| _ -> 0
end
| Some (Pdf.Array (Pdf.Name ("/Separation")::_)) -> ~-1
| Some (Pdf.Array (Pdf.Name ("/Indexed")::_)) -> ~-2
| _ -> 0
let lossless_out pdf ~pixel_threshold ~length_threshold extension s dict reference =
let old = !reference in
let restore () = reference := old in
let bpc = Pdf.lookup_direct pdf "/BitsPerComponent" dict in
let components = suitable_num pdf dict in
match components, bpc with
| (1 | 3 | 4 | -1 | -2), 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 (if !debug_image_processing then Printf.printf "pixel threshold not met\n%!"; None) else
let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
if size < length_threshold then (if !debug_image_processing then Printf.printf "length threshold not met\n%!"; None) else
begin
Pdfcodec.decode_pdfstream_until_unknown pdf s;
match Pdf.lookup_direct pdf "/Filter" (fst !reference) with Some _ -> restore (); 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" ^ 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);*)
if !debug_image_processing then Printf.printf "colourspace not suitable\n%!";
restore ();
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 =
complain_convert path_to_convert;
match lossless_out pdf ~pixel_threshold ~length_threshold ".jpg" s dict reference with
| None -> ()
| Some (_, _, _, -2, _, _) ->
if !debug_image_processing then Printf.printf "skipping indexed colorspace\n%!"
| 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; "-quality"; string_of_float qlossless ^ "%"] @
(if components = 1 then ["-colorspace"; "Gray"] else if components = 4 then ["-colorspace"; "CMYK"] else []) @
[out2]))
in
(*Printf.printf "%S\n" command;*) Sys.command command
in
if retcode = 0 then
begin
try
let result = open_in_bin out2 in
let newsize = in_channel_length result in
let perc_ok = float newsize /. float size < percentage_threshold /. 100. in
if newsize < size && perc_ok then
begin
if !debug_image_processing then Printf.printf "lossless to JPEG %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
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
else
begin
if !debug_image_processing then Printf.printf "no size reduction\n%!"
end;
close_in result
with
_ ->
remove out;
remove out2
end;
remove out;
remove out2
let test_components pdf dict =
match suitable_num pdf dict with -1 | -2 -> 1 | x -> x
let test_bpc pdf dict =
match Pdf.lookup_direct pdf "/BitsPerComponent" dict with
| Some (Pdf.Integer i) -> i
| _ -> 0
let lossless_resample pdf ~pixel_threshold ~length_threshold ~factor ~interpolate ~path_to_convert s dict reference =
complain_convert path_to_convert;
let in_components = test_components pdf dict in
let in_bpc = test_bpc pdf dict in
(*Printf.printf "***lossless_resample IN dictionary: %S\n" (Pdfwrite.string_of_pdf dict); *)
(*Printf.printf "\n***IN components = %i, bpc = %i\n" in_components in_bpc;*)
match lossless_out pdf ~pixel_threshold ~length_threshold ".png" s dict reference with
| None -> ()
| Some (_, _, _, 4, _, _) -> Printf.printf "lossless resampling for CMYK not supported yet\n%!"
| Some (out, out2, size, components, w, h) ->
let retcode =
let command =
Filename.quote_command path_to_convert
([out] @ (if components = 4 then ["-depth"; "8"; "-size"; string_of_int w ^ "x" ^ string_of_int h] else []) @
(if components = 1 then ["-define"; "png:color-type=0"; "-colorspace"; "Gray"] else if components = 3 then ["-define"; "-png:color-type=2"; "-colorspace"; "RGB"] else if components = 4 then ["-colorspace"; "CMYK"] else []) @
[if interpolate && components > -2 then "-resize" else "-sample"; string_of_float factor ^ "%"; out2])
in
(*Printf.printf "%S\n" command;*)
Sys.command command
in
try
if retcode = 0 then
begin
let result = open_in_bin out2 in
let newsize = in_channel_length result in
if newsize < size then
begin
reference :=
(match fst (obj_of_png_data (Pdfio.bytes_of_input_channel result)) with
| Pdf.Stream {contents = Pdf.Dictionary d, data} as s ->
let out_components = test_components pdf s in
let out_bpc = test_bpc pdf s in
(*Printf.printf "***OUT components = %i, bpc = %i\n" out_components out_bpc;*)
let rgb_to_grey_special =
let was_rgb =
match Pdf.lookup_direct pdf "/ColorSpace" dict with
| Some (Pdf.Name ("/DeviceRGB" | "/CalRGB")) -> true
| _ -> false
in
in_bpc = out_bpc && in_components = 3 && out_components = 1 && was_rgb
in
(*Printf.printf "***rgb_to_grey_special = %b\n" rgb_to_grey_special;*)
if (out_components <> in_components || in_bpc <> out_bpc) && not rgb_to_grey_special then
begin
if !debug_image_processing then Printf.printf "wrong bpc / components returned. Skipping.\n%!";
!reference
end
else
begin
if !debug_image_processing then Printf.printf "lossless resample %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
let d' = fold_right (fun (k, v) d -> if k <> "/ColorSpace" || rgb_to_grey_special then add k v d else d) d (match dict with Pdf.Dictionary x -> x | _ -> []) in
(*Printf.printf "***lossless_resample OUT dictionary: %S\n" (Pdfwrite.string_of_pdf (Pdf.Dictionary d')); *)
(Pdf.Dictionary d', data)
end
| _ -> assert false)
end
else
begin
if !debug_image_processing then Printf.printf "no size reduction\n%!"
end;
close_in result
end;
remove out;
remove out2
with _ ->
remove out;
remove out2
let lossless_resample_target_dpi objnum pdf ~pixel_threshold ~length_threshold ~factor ~target_dpi_info ~interpolate ~path_to_convert s dict reference =
let real_factor = factor /. Hashtbl.find target_dpi_info objnum *. 100. in
if real_factor < 100. then
lossless_resample pdf ~pixel_threshold ~length_threshold ~factor:real_factor ~interpolate ~path_to_convert s dict reference
else
if !debug_image_processing then Printf.printf "failed to meet dpi target\n%!"
let recompress_1bpp_jbig2_lossless ~pixel_threshold ~length_threshold ~path_to_jbig2enc pdf s dict reference =
complain_jbig2enc path_to_jbig2enc;
let old = !reference in
let restore () = reference := old in
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 (if !debug_image_processing then Printf.printf "pixel threshold not met\n%!") else (* (but also, jbig2enc fails on tiny images) *)
let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
if size < length_threshold then (if !debug_image_processing then Printf.printf "length threshold not met\n%!") else
begin
Pdfcodec.decode_pdfstream_until_unknown pdf s;
match Pdf.lookup_direct pdf "/Filter" (fst !reference) with
| Some x ->
if !debug_image_processing then Printf.printf "could not decode - skipping %s length %i\n%!" (Pdfwrite.string_of_pdf x) size;
restore ()
| None ->
let out = Filename.temp_file "cpdf" "convertin.pnm" in
let out2 = Filename.temp_file "cpdf" "convertout.jbig2" in
let fh = open_out_bin out in
let data = match s with Pdf.Stream {contents = _, Pdf.Got d} -> d | _ -> assert false in
pnm_to_channel_1_inverted fh w h data;
close_out fh;
let retcode =
let command = Filename.quote_command ~stdout:out2 path_to_jbig2enc ["-d"; "-p"; out] in
(*Printf.printf "%S\n" command;*) Sys.command command
in
if retcode <> 0 then
restore ()
else
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 "1bpp to JBIG2 %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
reference :=
(Pdf.remove_dict_entry
(Pdf.add_dict_entry
(Pdf.add_dict_entry dict "/Length" (Pdf.Integer newsize))
"/Filter"
(Pdf.Name "/JBIG2Decode")) "/DecodeParms"),
Pdf.Got (Pdfio.bytes_of_input_channel result)
end
else
begin
if !debug_image_processing then Printf.printf "no size reduction\n%!"
end;
close_in result
end;
remove out;
remove out2
end
(* Recompress 1bpp images (except existing JBIG2 compressed ones) to lossy jbig2 *)
let preprocess_jbig2_lossy ~path_to_jbig2enc ~jbig2_lossy_threshold ~length_threshold ~pixel_threshold ~dpi_threshold inrange highdpi pdf =
complain_jbig2enc path_to_jbig2enc;
let objnum_name_pairs = ref [] in
let process_obj objnum s =
match s with
| Pdf.Stream ({contents = dict, _} as reference) ->
let old = !reference in
let restore () = reference := old in
if Hashtbl.mem inrange objnum && (dpi_threshold = 0. || Hashtbl.mem highdpi objnum) then begin match
Pdf.lookup_direct pdf "/Subtype" dict,
Pdf.lookup_direct pdf "/BitsPerComponent" dict,
Pdf.lookup_direct pdf "/ImageMask" dict
with
| Some (Pdf.Name "/Image"), Some (Pdf.Integer 1), _
| Some (Pdf.Name "/Image"), _, Some (Pdf.Boolean true) ->
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 (if !debug_image_processing then Printf.printf "pixel threshold not met\n%!") else (* (but also, jbig2enc fails on tiny images) *)
let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
if size < length_threshold then (if !debug_image_processing then Printf.printf "length threshold not met\n%!") else
begin
Pdfcodec.decode_pdfstream_until_unknown pdf s;
match Pdf.lookup_direct pdf "/Filter" (fst !reference) with
| Some x ->
if !debug_image_processing then Printf.printf "could not decode - skipping %s length %i\n%!" (Pdfwrite.string_of_pdf x) size;
restore ()
| None ->
let out = Filename.temp_file "cpdf" "convertin.pnm" in
let fh = open_out_bin out in
let data = match s with Pdf.Stream {contents = _, Pdf.Got d} -> d | _ -> assert false in
pnm_to_channel_1_inverted fh w h data;
close_out fh;
if !debug_image_processing then Printf.printf "JBIG2Lossy: obj %i is suitable\n%!" objnum;
objnum_name_pairs := (objnum, out)::!objnum_name_pairs
end
| _ -> () (* not a 1bpp image *)
end
| _ -> () (* not a stream *)
in
Pdf.objiter process_obj pdf;
if length !objnum_name_pairs > 10000 then Pdfe.log "Too many jbig2 streams" else
if length !objnum_name_pairs = 0 then () else
let jbig2out = Filename.temp_file "cpdf" "jbig2" in
let retcode =
let command =
Filename.quote_command
path_to_jbig2enc
?stderr:(if !debug_image_processing then None else Some Filename.null)
(["-p"; "-s"; "-d"; "-t"; string_of_float jbig2_lossy_threshold; "-b"; jbig2out] @ map snd !objnum_name_pairs)
in
(*Printf.printf "%S\n" command;*) Sys.command command
in
iter remove (map snd !objnum_name_pairs);
if retcode = 0 then
begin
let globals = bytes_of_string (contents_of_file (jbig2out ^ ".sym")) in
let globalobj =
Pdf.addobj pdf (Pdf.Stream {contents = Pdf.Dictionary [("/Length", Pdf.Integer (bytes_size globals))], Pdf.Got globals})
in
iter2
(fun (objnum, _) i ->
let data = bytes_of_string (contents_of_file (jbig2out ^ Printf.sprintf ".%04i" i)) in
let basic_obj =
Pdf.Stream
{contents =
Pdf.Dictionary [("/Length", Pdf.Integer (bytes_size data));
("/Filter", Pdf.Name "/JBIG2Decode");
("/DecodeParms", Pdf.Dictionary [("/JBIG2Globals", Pdf.Indirect globalobj)])],
Pdf.Got data}
in
let dict = match Pdf.lookup_obj pdf objnum with Pdf.Stream {contents = d, _} -> d | _ -> Pdf.Dictionary [] in
Pdf.addobj_given_num pdf
(objnum,
(match basic_obj with
| Pdf.Stream {contents = Pdf.Dictionary d, data} ->
let d' = fold_right (fun (k, v) d -> add k v d) d (match dict with Pdf.Dictionary x -> x | _ -> []) in
Pdf.Stream {contents = Pdf.Dictionary d', data}
| _ -> assert false)))
!objnum_name_pairs
(indx0 !objnum_name_pairs)
end
else
begin
Pdfe.log "Call to jbig2enc failed"
end;
iter (fun i -> remove (jbig2out ^ Printf.sprintf ".%04i" i)) (indx0 !objnum_name_pairs);
remove (jbig2out ^ ".sym")
let process
~q ~qlossless ~onebppmethod ~jbig2_lossy_threshold ~length_threshold ~percentage_threshold ~pixel_threshold ~dpi_threshold
~factor ~interpolate ~path_to_jbig2enc ~path_to_convert range pdf
=
let inrange =
match images pdf range with
| `List l -> hashset_of_list (map (function `Assoc (("Object", `Int i)::_) -> i | _ -> assert false) l)
| _ -> assert false
in
let highdpi, target_dpi_info =
let objnums, dpi =
if dpi_threshold = 0. && factor > 0. then ([], []) else
let results = image_resolution pdf range max_float in
(*iter (fun (_, _, _, _, wdpi, hdpi, objnum) -> Printf.printf "From image_resolution %f %f %i\n" wdpi hdpi objnum) results;*)
let cmp (_, _, _, _, _, _, a) (_, _, _, _, _, _, b) = compare a b in
let sets = collate cmp (sort cmp results) in
let heads = map hd (map (sort (fun (_, _, _, _, a, b, _) (_, _, _, _, c, d, _) -> compare (fmin a b) (fmin c d))) sets) in
(*iter (fun (_, _, _, _, wdpi, hdpi, objnum) -> Printf.printf "Lowest resolution exemplar %f %f %i\n" wdpi hdpi objnum) heads;*)
let needed = keep (fun (_, _, _, _, wdpi, hdpi, objnum) -> fmin wdpi hdpi > dpi_threshold) heads in
(*iter (fun (_, _, _, _, wdpi, hdpi, objnum) -> Printf.printf "keep %f %f %i\n" wdpi hdpi objnum) needed;*)
map (fun (_, _, _, _, _, _, objnum) -> objnum) needed,
map (fun (_, _, _, _, wdpi, hdpi, objnum) -> (objnum, fmin wdpi hdpi)) heads
(*iter (fun (x, d) -> Printf.printf "obj %i at %f dpi\n" x d) r; r*)
in
hashset_of_list objnums, hashtable_of_dictionary dpi
in
begin match onebppmethod with "JBIG2Lossy" -> preprocess_jbig2_lossy ~path_to_jbig2enc ~jbig2_lossy_threshold ~dpi_threshold ~length_threshold ~pixel_threshold inrange highdpi pdf | _ -> () end;
let nobjects = Pdf.objcard pdf in
let ndone = ref 0 in
let process_obj objnum s =
match s with
| Pdf.Stream ({contents = dict, _} as reference) ->
ndone += 1;
if Hashtbl.mem inrange objnum && (dpi_threshold = 0. || Hashtbl.mem highdpi objnum) then begin match
Pdf.lookup_direct pdf "/Subtype" dict,
Pdf.lookup_direct pdf "/Filter" dict,
Pdf.lookup_direct pdf "/BitsPerComponent" dict,
Pdf.lookup_direct pdf "/ImageMask" dict
with
| Some (Pdf.Name "/Image"), Some (Pdf.Name "/DCTDecode" | Pdf.Array [Pdf.Name "/DCTDecode"]), _, _ ->
if q < 100. then
begin
if !debug_image_processing then Printf.printf "(%i/%i) Object %i (JPEG)... %!" !ndone nobjects objnum;
jpeg_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~q ~path_to_convert s dict reference
end
| Some (Pdf.Name "/Image"), _, Some (Pdf.Integer 1), _
| Some (Pdf.Name "/Image"), _, _, Some (Pdf.Boolean true) ->
begin match onebppmethod with
| "JBIG2" ->
begin
if !debug_image_processing then Printf.printf "(%i/%i) object %i (1bpp)... %!" !ndone nobjects objnum;
recompress_1bpp_jbig2_lossless ~pixel_threshold ~length_threshold ~path_to_jbig2enc pdf s dict reference
end
| _ -> ()
end
| Some (Pdf.Name "/Image"), _, _, _ ->
if qlossless < 101. then
begin
if !debug_image_processing then Printf.printf "(%i/%i) object %i (lossless)... %!" !ndone nobjects objnum;
lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~qlossless ~path_to_convert s dict reference
end
else
begin
if factor < 101. then
begin
if !debug_image_processing then Printf.printf "(%i/%i) object %i (lossless)... %!" !ndone nobjects objnum;
if factor < 0. then
lossless_resample_target_dpi objnum pdf ~pixel_threshold ~length_threshold ~factor:~-.factor ~target_dpi_info ~interpolate ~path_to_convert s dict reference
else
lossless_resample pdf ~pixel_threshold ~length_threshold ~factor ~interpolate ~path_to_convert s dict reference
end
end
| _ -> () (* not an image *)
end
| _ -> ndone += 1 (* not a stream *)
in
Pdf.objiter process_obj pdf