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cpdf-source
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Lossless to JPEG CMYK now working

This commit is contained in:
John Whitington 2023-12-19 19:12:56 +00:00
parent 8d64e1efd7
commit 5631cfd724
1 changed files with 22 additions and 7 deletions
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29
cpdfimage.ml
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@ -39,6 +39,15 @@ let pnm_to_channel_8 ch w h s =
done
done
let cmyk_to_channel_32 ch w h s =
let pos = ref 0 in
for y = 1 to h do
for x = 1 to w * 4 do
output_byte ch (255 - bget s !pos);
incr pos
done
done
let jbig2_serial = ref 0
let jbig2_globals = null_hash ()
@ -483,6 +492,8 @@ let image_of_input fobj i =
(* FIXME What about predictors? Audit to see if files get smaller. *)
(* FIXME if lossy only 5% smaller, ignore? Set this parameter... *)
(* FIXME error handling for Sys.remove, others *)
(* FIXME DeviceCYMK - use the convert CYMK samples format *)
(* FIXME Test JPEG to JPEG on CYMK - is colourspace retained, or do we need to add -colorspace CMYK? *)
let process pdf ~q ~qlossless ~path_to_convert =
let process_obj _ s =
match s with
@ -522,32 +533,36 @@ let process pdf ~q ~qlossless ~path_to_convert =
match Pdf.lookup_direct pdf "/ColorSpace" dict with
| Some (Pdf.Name "/DeviceRGB") -> 3
| Some (Pdf.Name "/DeviceGray") -> 1
| Some (Pdf.Name "/DeviceCMYK") -> 4
| 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
| _ -> 0
in
begin match suitable_num, bpc with
| (1 | 3), Some (Pdf.Integer 8) ->
| (1 | 3 | 4), Some (Pdf.Integer 8) ->
let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
Pdfcodec.decode_pdfstream_until_unknown pdf s;
begin match Pdf.lookup_direct pdf "/Filter" (fst !reference) with Some _ -> () | None ->
let out = Filename.temp_file "cpdf" "convertin" ^ ".pnm" in
let out2 = Filename.temp_file "cpdf" "convertout" ^ ".jpg" in
let fh = open_out_bin out 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
let out = Filename.temp_file "cpdf" "convertin" ^ (if suitable_num < 4 then ".pnm" else ".cmyk") in
let out2 = Filename.temp_file "cpdf" "convertout" ^ ".jpg" in
let fh = open_out_bin out in
let data = match s with Pdf.Stream {contents = _, Pdf.Got d} -> d | _ -> assert false in
(if suitable_num = 3 then pnm_to_channel_24 else pnm_to_channel_8) fh w h data;
(if suitable_num = 3 then pnm_to_channel_24 else
if suitable_num = 4 then cmyk_to_channel_32 else pnm_to_channel_8) fh w h data;
close_out fh;
let retcode =
let command =
(Filename.quote_command path_to_convert
([out; "-quality"; string_of_int qlossless ^ "%"] @
(if suitable_num = 1 then ["-colorspace"; "Gray"] else []) @
((if suitable_num = 4 then ["-depth"; "8"; "-size"; string_of_int w ^ "x" ^ string_of_int h] else []) @
[out; "-quality"; string_of_int qlossless ^ "%"] @
(if suitable_num = 1 then ["-colorspace"; "Gray"] else if suitable_num = 4 then ["-colorspace"; "CMYK"] else []) @
[out2]))
in
(*Printf.printf "%S\n" command;*)