pdf - 使用ghostscript将单个页面拆分为两个页面

Question

我有一个 pdf，其中包含演示文稿幻灯片和每页多张幻灯片。如何使用 ghostscript 拆分文件以便每页有一张幻灯片？

Answer 1

很久以前，我在 comp.lang.postscript 上为某人写了一些代码来执行此操作，同样是用于 PowerPoint 幻灯片。此 PostScript 代码假定所有“子页面”(即幻灯片)在 PDF 页面上的大小和位置都相同，并且所有 PDF 页面的大小都相同。将以下内容保存为名为 pdf_slice.ps 的文件，并按照注释中描述的用法进行操作。

%!PS
% Copyright (C) 2011 Artifex Software, Inc.  All rights reserved.
% 
% This software is provided AS-IS with no warranty, either express or
% implied.
% 
% This software is distributed under license and may not be copied,
% modified or distributed except as expressly authorized under the terms
% of the license contained in the file LICENSE in this distribution.
% 
% For more information about licensing, please refer to
% http://www.ghostscript.com/licensing/. For information on
% commercial licensing, go to http://www.artifex.com/licensing/ or
% contact Artifex Software, Inc., 101 Lucas Valley Road #110,
% San Rafael, CA  94903, U.S.A., +1(415)492-9861.
%
% Slice up a PDF file
%
% usage: gs -sFile=____.pdf  -dSubPagesX= -dSubPagesY= [-dSubPageOrder=] [-dVerbose=]pdf_slice.ps
%
% SubPageOrder is a bit field;
% Default = 0
% Bit 0 - 0 = top to bottom
%         1 = bottom to top
% Bit 1 - 0 = left to right
%         1 = right to left
% Bit 3 - 0 = increase x then y
%       - 1 = increase y then x
% 
% 0 - page 1 at top left, increasing left to right, top to bottom
% 1 - page 1 at bottom left increasing left to right, bottom to top
% 2 - page 1 at top right, increasing right to left, top to bottom
% 3 - page 1 at bottom right increasing right to left, bottom to top
% 4 - page 1 at top left, increasing top to bottom, left to right
% 5 - page 1 at bottom left increasing bottom to top, left to right
% 6 - page 1 at top right, increasing top to bottom, right to left 
% 7 - page 1 at bottom right increasing bottom to top, right to left

%
% Check the parameters to see they are present and of the correct type
%
/Usage {
  (  usage: gs -dNODISPLAY -q -sFile=____.pdf \n) =
  (     -dSubPagesX= -dSubPagesY= [-dSubPageOrder=] pdf_slice.ps \n) =
  (Please see comments in pdf_slice.ps for more details) =
  flush
  quit
} bind def

/Verbose where not {
  /Verbose false def
}{
  pop /Verbose true def
} ifelse

/File where not {
  (\n   *** Missing source file. \(use -sFile=____.pdf\)\n) =
  Usage
} {
  pop
}ifelse

/SubPagesX where not {
  (\n   *** SubPagesX not integer! \(use -dSubPagesX=\)\n) =
  Usage
} {
  Verbose { (SubPagesX ) print } if 
  SubPagesX type 
  Verbose { dup == } if
  /integertype eq not {
    (\n   *** SubPagesX not integer! \(use -dSubPagesX=\)\n) =
    Usage
  }
  pop 
}ifelse

/SubPagesY where not {
  (\n   *** SubPagesY not integer! \(use -dSubPagesY=\)\n) =
  Usage
} {
  Verbose { (SubPagesY ) print } if
  SubPagesY type 
  Verbose { dup == } if
  /integertype eq not {
    (\n   *** SubPagesY not integer! \(use -dSubPagesY=\)\n) =
    Usage
  }
  pop 
}ifelse

/SubPageOrder where not {
  /SubPageOrder 0 def
} {
  Verbose { (SubPageOrder ) print } if
  SubPageOrder type 
  Verbose { dup == } if
  dup == 
  /integertype eq not {
    (\n   *** SubPageOrder not integer! \(use -dSubPageOrder=\)\n) =
    Usage
  }
  pop 
}ifelse

% 
% Turns off most messages
%
/QUIET true def     % in case they forgot

%() =

%
% Open the PDF file and tell the PDF interpreter to start dealing with it
%
File dup (r) file runpdfbegin pop
/PDFPageCount pdfpagecount def

%
% Set up our bookkeeping
%
% First get the size of the page from page 1 of the PDF file
% We assume that all PDF pages are the same size.
%
1 pdfgetpage currentpagedevice
1 index get_any_box 
exch pop dup 2 get exch 3 get
/PDFHeight exch def
/PDFWidth exch def

%
% Now get the page size of the current device. We are assuming that
% this is the size of the individual sub-pages in the original PDF. NB
% This assumes no margins between sub-pages, all sub-pages the same size.
%
currentpagedevice /PageSize get
dup 0 get /SubPageWidth exch def
1 get /SubPageHeight exch def

% 
% Calculate the margins. This is the margin between the page border and
% the enclosed group of sub-pages, we assume there are no borders
% between sub pages.
%
/TopMargin PDFHeight SubPageHeight SubPagesY mul sub 2 div def
/LeftMargin PDFWidth SubPageWidth SubPagesX mul sub 2 div def

Verbose {
  (PDFHeight = ) print PDFHeight ==
  (PDFWidth = ) print PDFWidth ==
  (SubPageHeight = ) print SubPageHeight ==
  (SubPageWidth = ) print SubPageWidth ==
  (TopMargin = ) print TopMargin ==
  (LeftMmargin = ) print LeftMargin ==
} if

%
% This rouitne calculates and sets the PageOffset in the page device
% dictionary for each subpage, so that the PDF page is 'moved' in such 
% a way that the required sub page is under the 'window' which is the current
% page being imaged.
%
/NextPage {
    SubPageOrder 2 mod 0 eq {
        /H SubPagesY SubPageY sub SubPageHeight mul TopMargin add def
    }{
        /H SubPageY 1 sub SubPageHeight mul TopMargin add def
    } ifelse
    SubPageOrder 2 div floor cvi 2 mod 0 eq {
        /W SubPageX 1 sub SubPageWidth mul LeftMargin add def
    }{
        /W SubPagesX SubPageX sub SubPageWidth mul LeftMargin add def
    } ifelse
    << /PageOffset [W neg H neg]>> setpagedevice

Verbose {
  (SubPageX ) print SubPageX ==
  (SubPageY ) print SubPageY ==
  (X Offset ) print W ==
  (Y Offset ) print H == flush
} if

    PDFPage
} bind def

%
% The main loop
% For every page in the original PDF file
%
1 1 PDFPageCount 
{
    /PDFPage exch def

    % Do the gross ordering here rather than in
    % NextPage. We eiither process rows and then 
    % columns, or columns then rows, depending on
    % Bit 3 of SubPageorder
    SubPageOrder 3 le {
        1 1 SubPagesY {
            /SubPageY exch def
            1 1 SubPagesX {
                /SubPageX exch def
                NextPage
                pdfgetpage
                pdfshowpage
            } for
        } for
    } {
        1 1 SubPagesX {
            /SubPageX exch def
            1 1 SubPagesY {
                /SubPageY exch def
                NextPage
                pdfgetpage
                pdfshowpage
            } for
        } for
    } ifelse
} for