towards better -process-images-info
This commit is contained in:
John Whitington
parent
c953d0f2a9
commit
70e9092e01
48
cpdfimage.ml
48
cpdfimage.ml
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@ -494,10 +494,10 @@ let image_of_input fobj i =
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let jpeg_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~q ~path_to_convert s dict reference =
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let w = match Pdf.lookup_direct pdf "/Width" dict with Some (Pdf.Integer i) -> i | _ -> error "bad width" in
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let h = match Pdf.lookup_direct pdf "/Height" dict with Some (Pdf.Integer i) -> i | _ -> error "bad height" in
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if w * h < pixel_threshold then () else
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if w * h < pixel_threshold then (if !debug_image_processing then Printf.printf "pixel threshold not met\n%!") else
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Pdf.getstream s;
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let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
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if size < length_threshold then () else
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if size < length_threshold then (if !debug_image_processing then Printf.printf "length threshold not met\n%!") else
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let out = Filename.temp_file "cpdf" "convertin" ^ ".jpg" in
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let out2 = Filename.temp_file "cpdf" "convertout" ^ ".jpg" in
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let fh = open_out_bin out in
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@ -542,9 +542,9 @@ let lossless_out pdf ~pixel_threshold ~length_threshold extension s dict referen
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| (1 | 3 | 4 | -1), Some (Pdf.Integer 8) ->
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let w = match Pdf.lookup_direct pdf "/Width" dict with Some (Pdf.Integer i) -> i | _ -> error "bad width" in
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let h = match Pdf.lookup_direct pdf "/Height" dict with Some (Pdf.Integer i) -> i | _ -> error "bad height" in
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if w * h < pixel_threshold then None else
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if w * h < pixel_threshold then (if !debug_image_processing then Printf.printf "pixel threshold not met\n%!"; None) else
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let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
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if size < length_threshold then None else
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if size < length_threshold then (if !debug_image_processing then Printf.printf "length threshold not met\n%!"; None) else
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begin
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Pdfcodec.decode_pdfstream_until_unknown pdf s;
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match Pdf.lookup_direct pdf "/Filter" (fst !reference) with Some _ -> None | None ->
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@ -586,13 +586,17 @@ let lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshol
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let newsize = in_channel_length result in
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if newsize < size then
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begin
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if !debug_image_processing then Printf.printf "Lossless to JPEG %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
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if !debug_image_processing then Printf.printf "lossless to JPEG %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
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reference :=
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(Pdf.add_dict_entry
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(Pdf.add_dict_entry dict "/Length" (Pdf.Integer newsize))
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"/Filter"
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(Pdf.Name "/DCTDecode")),
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Pdf.Got (Pdfio.bytes_of_input_channel result)
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end
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else
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begin
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if !debug_image_processing then Printf.printf "no size reduction\n%!"
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end;
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close_in result
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end;
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@ -617,13 +621,17 @@ let lossless_resample pdf ~pixel_threshold ~length_threshold ~percentage_thresho
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let newsize = in_channel_length result in
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if newsize < size then
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begin
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if !debug_image_processing then Printf.printf "Lossless to JPEG %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
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if !debug_image_processing then Printf.printf "lossless resample %i -> %i (%i%%)\n%!" size newsize (int_of_float (float newsize /. float size *. 100.));
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reference :=
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(Pdf.add_dict_entry
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(Pdf.add_dict_entry dict "/Length" (Pdf.Integer newsize))
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"/Filter"
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(Pdf.Name "/DCTDecode")),
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Pdf.Got (Pdfio.bytes_of_input_channel result)
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end
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else
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begin
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if !debug_image_processing then Printf.printf "no size reduction\n%!"
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end;
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close_in result
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end;
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@ -633,11 +641,11 @@ let lossless_resample pdf ~pixel_threshold ~length_threshold ~percentage_thresho
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let recompress_1bpp_jbig2_lossless ~pixel_threshold ~length_threshold ~path_to_jbig2enc pdf s dict reference =
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let w = match Pdf.lookup_direct pdf "/Width" dict with Some (Pdf.Integer i) -> i | _ -> error "bad width" in
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let h = match Pdf.lookup_direct pdf "/Height" dict with Some (Pdf.Integer i) -> i | _ -> error "bad height" in
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if w * h < pixel_threshold then () else (* pixel_threshold (but also, jbig2enc fails on tiny images) *)
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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) *)
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let size = match Pdf.lookup_direct pdf "/Length" dict with Some (Pdf.Integer i) -> i | _ -> 0 in
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if size < length_threshold then () else
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if size < length_threshold then if !debug_image_processing then Printf.printf "length threshold not met\n%!" else
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Pdfcodec.decode_pdfstream_until_unknown pdf s;
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match Pdf.lookup_direct pdf "/Filter" (fst !reference) with Some _ -> () | None ->
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match Pdf.lookup_direct pdf "/Filter" (fst !reference) with Some _ -> if !debug_image_processing then Printf.printf "could not decode - skipping\n%!" | None ->
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let out = Filename.temp_file "cpdf" "convertin" ^ ".pnm" in
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let out2 = Filename.temp_file "cpdf" "convertout" ^ ".jbig2" in
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let fh = open_out_bin out in
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@ -662,6 +670,10 @@ let recompress_1bpp_jbig2_lossless ~pixel_threshold ~length_threshold ~path_to_j
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"/Filter"
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(Pdf.Name "/JBIG2Decode")) "/DecodeParms"),
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Pdf.Got (Pdfio.bytes_of_input_channel result)
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end
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else
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begin
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if !debug_image_processing then Printf.printf "no size reduction\n%!"
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end;
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close_in result
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end;
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@ -688,25 +700,33 @@ let process
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Pdf.lookup_direct pdf "/ImageMask" dict
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with
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| Some (Pdf.Name "/Image"), Some (Pdf.Name "/DCTDecode" | Pdf.Array [Pdf.Name "/DCTDecode"]), _, _ ->
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if !debug_image_processing then Printf.printf "(%i/%i) Object %i (JPEG)...\n%!" !ndone nobjects objnum;
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begin match q with
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| Some q ->
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if q < 100 then jpeg_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~q ~path_to_convert s dict reference
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if q < 100 then
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begin
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if !debug_image_processing then Printf.printf "(%i/%i) Object %i (JPEG)... %!" !ndone nobjects objnum;
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jpeg_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~q ~path_to_convert s dict reference
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end
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| None -> ()
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end
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| Some (Pdf.Name "/Image"), _, Some (Pdf.Integer 1), _
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| Some (Pdf.Name "/Image"), _, _, Some (Pdf.Boolean true) ->
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if !debug_image_processing then Printf.printf "(%i/%i) object %i (1bpp)...\n%!" !ndone nobjects objnum;
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begin match onebppmethod with
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| Some "JBIG2" ->
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begin
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if !debug_image_processing then Printf.printf "(%i/%i) object %i (1bpp)... %!" !ndone nobjects objnum;
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recompress_1bpp_jbig2_lossless ~pixel_threshold ~length_threshold ~path_to_jbig2enc pdf s dict reference
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end
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| _ -> ()
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end
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| Some (Pdf.Name "/Image"), _, _, _ ->
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if !debug_image_processing then Printf.printf "(%i/%i) object %i (lossless)...\n%!" !ndone nobjects objnum;
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begin match qlossless with
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| Some qlossless ->
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if qlossless < 101 then lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~qlossless ~path_to_convert s dict reference
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if qlossless < 101 then
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begin
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if !debug_image_processing then Printf.printf "(%i/%i) object %i (lossless)... %!" !ndone nobjects objnum;
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lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~qlossless ~path_to_convert s dict reference
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end
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| None -> ()
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end
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| _ -> () (* not an image *)
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