Scaffolding for -lossless-resample

cpdfcommand.ml

@@ -528,7 +528,9 @@ type args =
    mutable onebppmethod : string;
    mutable pixel_threshold : int;
    mutable length_threshold : int;
-   mutable percentage_threshold : int}
+   mutable percentage_threshold : int;
+   mutable resample_factor : int;
+   mutable resample_interpolate : bool}
 
 let args =
   {op = None;
@@ -657,8 +659,15 @@ let args =
    onebppmethod = "";
    pixel_threshold = 25;
    length_threshold = 100;
-   percentage_threshold = 99}
+   percentage_threshold = 99;
+   resample_factor = 100;
+   resample_interpolate = false}
 
+(* Do not reset original_filename or cpdflin or was_encrypted or
+was_decrypted_with_owner or recrypt or producer or creator or path_to_* or
+gs_malformed or gs_quiet or no-warn-rotate, since we want these to work
+across ANDs. Or squeeze options: a little odd, but we want it to happen on
+eventual output. Or -debug-force (from v2.6). *)
 let reset_arguments () =
   args.op <- None;
   args.preserve_objstm <- true;
@@ -768,11 +777,8 @@ let reset_arguments () =
   args.pixel_threshold <- 25;
   args.length_threshold <- 100;
   args.percentage_threshold <- 99;
-  (* Do not reset original_filename or cpdflin or was_encrypted or
-   was_decrypted_with_owner or recrypt or producer or creator or path_to_* or
-   gs_malformed or gs_quiet or no-warn-rotate, since we want these to work
-   across ANDs. Or squeeze options: a little odd, but we want it to happen on
-   eventual output. Or -debug-force (from v2.6). *)
+  args.resample_factor <- 100;
+  args.resample_interpolate <- false;
   clear Cpdfdrawcontrol.fontpack_initialised
 
 (* Prefer a) the one given with -cpdflin b) a local cpdflin, c) otherwise assume
@@ -1956,6 +1962,12 @@ let setlengththreshold i =
 let setpercentagethreshold i =
   args.percentage_threshold <- i
 
+let setlosslessresample i =
+  args.resample_factor <- i
+
+let setresampleinterpolate b =
+  args.resample_interpolate <- b
+
 let setprocessimagesinfo () =
   set Cpdfimage.debug_image_processing
 
@@ -2760,6 +2772,12 @@ and specs =
    ("-percentage-threshold",
      Arg.Int setpercentagethreshold,
      " Only substitute lossy image when smaller than this");
+   ("-lossless-resample",
+     Arg.Int setlosslessresample,
+     " Resample lossless images to given part of original");
+   ("-resample-interpolate",
+     Arg.Bool setresampleinterpolate,
+     " Interpolate when resampling");
    ("-squeeze",
      Arg.Unit setsqueeze,
      " Squeeze");
@@ -4499,7 +4517,8 @@ let go () =
       let pdf = get_single_pdf args.op false in
         Cpdfimage.process
           ~q:args.jpegquality ~qlossless:args.jpegqualitylossless ~onebppmethod:args.onebppmethod
-          ~length_threshold:args.length_threshold ~pixel_threshold:args.pixel_threshold ~percentage_threshold:args.percentage_threshold
+          ~length_threshold:args.length_threshold ~percentage_threshold:args.percentage_threshold ~pixel_threshold:args.pixel_threshold 
+          ~factor:args.resample_factor ~interpolate:args.resample_interpolate
           ~path_to_jbig2enc:args.path_to_jbig2enc ~path_to_convert:args.path_to_convert pdf;
         write_pdf false pdf
 

cpdfimage.ml

@@ -617,7 +617,7 @@ let lossless_to_jpeg pdf ~pixel_threshold ~length_threshold ~percentage_threshol
   remove out;
   remove out2
 
-let lossless_resample pdf ~pixel_threshold ~length_threshold ~percentage_threshold~interpolate ~path_to_convert s dict reference =
+let lossless_resample pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~factor ~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 = 
@@ -702,7 +702,7 @@ let recompress_1bpp_jbig2_lossless ~pixel_threshold ~length_threshold ~path_to_j
 (* Lossless to JPEG: 8bpp Grey, 8bpp RGB, 8bpp CMYK including separation and ICCBased colourspaces *)
 (* 1 bit: anything to JBIG2 lossless (no globals) *)
 let process
-  ?q ?qlossless ?onebppmethod ~length_threshold ~percentage_threshold ~pixel_threshold
+  ?q ?qlossless ?onebppmethod ~length_threshold ~percentage_threshold ~pixel_threshold ~factor ~interpolate
   ~path_to_jbig2enc ~path_to_convert pdf
 =
   let nobjects = Pdf.objcard pdf in
@@ -745,6 +745,14 @@ let process
                     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 < 100 then
+                      begin
+                        if !debug_image_processing then Printf.printf "(%i/%i) object %i (lossless)... %!" !ndone nobjects objnum;
+                        lossless_resample pdf ~pixel_threshold ~length_threshold ~percentage_threshold ~factor ~interpolate ~path_to_convert s dict reference
+                      end
+                  end
             | None -> ()
             end
         | _ -> () (* not an image *)

cpdfimage.mli

@@ -17,6 +17,7 @@ val images : Pdf.t -> int list -> Cpdfyojson.Safe.t
 val process :
   ?q:int -> ?qlossless:int -> ?onebppmethod:string ->
   length_threshold:int -> percentage_threshold:int -> pixel_threshold:int ->
+  factor:int -> interpolate:bool ->
   path_to_jbig2enc:string -> path_to_convert:string -> Pdf.t -> unit
 
 (**/**)