From 68fe5bd5f793ee0e45bc9908499e567556b6d40d Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Tue, 26 Nov 2024 20:18:31 +0000
Subject: [PATCH] Scaffolding for -output-[jpeg|png]

---
 Changes        |  2 +-
 cpdfcommand.ml | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Changes b/Changes
index 6b69bf2..5d5839f 100644
--- a/Changes
+++ b/Changes
@@ -5,7 +5,7 @@ New features:
 o New -center-to-fit centres pages on a given paper size
 o New -jpeg-to-jpeg-scale and -jpeg-to-jpeg-dpi
 o Rasterize PDFs by calling out to GhostScript
-o Convert to PNG/JPEG by calling out to GhostScript
+o Extract pages as PNG/JPEG by calling out to GhostScript
 
 Extended features:
 
diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index 0aea7fc..687e809 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -231,6 +231,7 @@ type op =
   | SetLanguage of string
   | Redact
   | Rasterize
+  | OutputImage of string
 
 let string_of_op = function
   | PrintFontEncoding _ -> "PrintFontEncoding"
@@ -385,6 +386,7 @@ let string_of_op = function
   | SetLanguage _ -> "SetLanguage"
   | Redact -> "Redact"
   | Rasterize -> "Rasterize"
+  | OutputImage _ -> "OutputImage"
 
 (* Inputs: filename, pagespec. *)
 type input_kind = 
@@ -940,7 +942,7 @@ let banned banlist = function
   | OCGRename | OCGList | OCGOrderAll | PrintFontEncoding _ | TableOfContents | Typeset _ | Composition _
   | TextWidth _ | SetAnnotations _ | CopyAnnotations _ | ExtractStream _ | PrintObj _ | ReplaceObj _
   | Verify _ | MarkAs _ | RemoveMark _ | ExtractStructTree | ReplaceStructTree _ | SetLanguage _
-  | PrintStructTree | Rasterize
+  | PrintStructTree | Rasterize | OutputImage _
      -> false (* Always allowed *)
   (* Combine pages is not allowed because we would not know where to get the
   -recrypt from -- the first or second file? *)
@@ -3010,6 +3012,8 @@ let specs =
    ("-rasterize-res", Arg.Float (fun f -> args.rast_res <- f), " Rastierization resolution");
    ("-rasterize-annots", Arg.Unit (fun () -> args.rast_annots <- true), " Rasterize annotations");
    ("-rasterize-no-antialias", Arg.Unit (fun () -> args.rast_antialias <- false), " Don't antialias when rasterizing");
+   ("-output-jpeg", Arg.String (fun s -> args.op <- Some (OutputImage s)), " Output pages as JPEGs");
+   ("-output-png", Arg.String (fun s -> args.op <- Some (OutputImage s)), " Output pages as PNGs");
    (* These items are undocumented *)
    ("-debug", Arg.Unit setdebug, "");
    ("-debug-crypt", Arg.Unit (fun () -> args.debugcrypt <- true), "");
@@ -3729,6 +3733,9 @@ let rasterize antialias device res annots pdf range =
     Sys.remove tmppdf;
     pdf
 
+let write_images spec pdf range =
+  ()
+
 (* Main function *)
 let go () =
   check_bookmarks_mistake ();
@@ -4836,6 +4843,10 @@ let go () =
       let pdf = get_single_pdf args.op false in
       let range = parse_pagespec_allow_empty pdf (get_pagespec ()) in
         write_pdf false (rasterize args.rast_antialias args.rast_device args.rast_res args.rast_annots pdf range)
+  | Some (OutputImage spec) ->
+      let pdf = get_single_pdf args.op false in
+      let range = parse_pagespec_allow_empty pdf (get_pagespec ()) in
+        write_images spec pdf range
 
 (* Advise the user if a combination of command line flags makes little sense,
 or error out if it make no sense at all. *)