View source for Talk:PDF: The Portable Document Format

== G4-compressed-TIFF-to-PDF-conversion FAQ ==

<h3>G4-compressed-TIFF-to-PDF-conversion FAQ</h3>
<p>        Last change: 02 Aug 2006 (most content is from 2003 though),
        contact Holger Blasum, <img src="http://c42pdf.ffii.org/email.png" alt="c42pdf ATT ffii DOTT org"> for comments, critique or updates</p>
<h3>Why PDF ?</h3>
<p>        <a href="http://partners.adobe.com/asn/developer/acrosdk/docs.html#filefmtspecs">PDF</a>

 readers are somewhat more common than TIFF readers.</p>
<h3>What is an G4 compressed TIFF ?, example ?</h3>
<p>        A TIFF file that has been compressed according to the ITU G4 Fax compression standard, so typically it is a black-and-white scan (may consist of several pages). Here is an example
        <a href="http://c42pdf.ffii.org/src/sample.tif">(TIFF)</a> , <a href="http://c42pdf.ffii.org/src/sample.pdf">(PDF)</a> .</p>
<h3>How can I check the compression of any TIFF / PDF files ?</h3>

<ul>
<li><p>TIFF: <code>tiffdump sample.tif</code> (libtiff-tools)
        or <code>tifftopnm -headerdump file.tiff &gt; /dev/null</code> (netpbm)</p></li>
<li><p>PDF: open PDF in text editor, search for <code>/CCITTFaxDecode</code>, or
        <code>/FlateDecode</code> or if it is in another format for <code>/Filter</code> 
        in the Objects of Subtype <code>/Image</code></p></li>

</ul>
<h3>Which compression options are there for monocolor PDF and TIFF ?</h3>
<p>        (see also: Jason Summers, <a href="http://groups.google.com/groups?q=TIFF+deflate+compression&hl=en&rnum=10&selm=76mqnp%249j3%241%40news-2.news.gte.net">comp.infosystems.www.authoring.images, 1999/01/02</a></p>

<ul>
<li><p>no compression ("bitmap"), should not be used</p></li>
<li><p>packbit compression, not very powerful, in the PDF spec this is 
        called "RunLengthDecode"</p></li>
<li><p>CCITT G3 compression, ITU fax standard, not optimal</p></li>
<li><p>LZW general compression algorithm, patented, 
        should not be used</p></li>

<li><p>CCITT G4 compression, ITU fax standard</p></li>
<li><p>(PDF since version 1.2): Flate (zip/"gzip") general compression 
        algorithm</p></li>

</ul>
<p>        In practice, for (a random) 300 dpi scan this boiled down to:
        1.121 kb for no compression, 182 kb for packbit compression, 
        113 kb for G3 compression, 78 kb for G4 compression and 
        71 kb for Flate compression. But don't take this benchmark
        too serious, this varies widely ! </p>
<h3>File size of produced PDFs vs incoming G4 compressed TIFFs</h3>
<p>        Produced PDFs should usually not be more than 2% larger than incoming
        TIFFs. Depending on the structure of the TIFFs output may be even
        smaller and by changing compression (see below) you may typically 
        gain another one-digit percentage. Deviations of more than 10% in 
        either direction are atypical (though John has shown me some formally
        correct G4 compressed TIFF files that had huge chunks (15%) 
        of repetitive data inside - this can be checked in a text editor 
        or with tiffsplit).</p>
<h3>What conversion programs are there ? </h3>
<p>        Well there is <a href="http://c42pdf.ffii.org">c42pdf</a> from this site.</p>

<p>        Most more general converters come in a package that as 
        command line tools install several small programs: </p>

<ul>
<li><p>the <a href="http://www.libtiff.org/">libtiff-tools</a>, the important 
        command line tools (for TIFF conversion) are <code>tiffcp</code>, tiff2ps', 
        <code>tiffdump</code> and <code>tiffsplit</code> (AFAIK the best tool for TIFF handling) </p></li>

<li><p><a href="http://www.ghostscript.com/">Ghostscript</a>, the important command 
        line tools are <code>ps2pdf</code>, <code>gs</code> or <code>gswin32</code> (Win version), 
        (AFAIK the best tool for Postscript/PDF parsing)</p></li>
<li><p><a href="http://www.imagemagick.org/">ImageMagick</a>, the important 
        command line tool is <code>convert</code> (a swiss army knife for conversions 
        of all types)</p></li>

<li><p><a href="http://www.inf.bme.hu/~pts/sam2p/">sam2p</a>, similar raster
converter to ImageMagick with less library dependencies, output sometimes smaller than convert.
</ul>
<p>        You also may want to have a look at: </p>

<ul>
<li><p>Other free software for PDF imaging: <a href="http://sourceforge.net/projects/netpbm/">netpbm</a>, important
        command tools are <code>tifftopnm</code>, <code>pnmtops</code> and 'pnmtotiff';
        <a href="http://www.foolabs.com/xpdf/">Xpdf</a> (cool pdfimages command)</p></li>

<li><p><a href="http://tumble.brouhaha.com/">tumble</a>, (GPL) Tumble converts one or more TIFF (B&W only) and JPEG files into a PDF file. It was developed primarily for use with scanned images. B&W images will be encoded with Group 4 fax (T.6) lossless compression. JPEG images are embedded as-is. Tumble supports multi-page TIFF files, and can generate PDF outline entries (bookmarks) based on the file name and/or the page number. </p></li>
<li><p>free-as-beer: <a href="http://www.fastio.com/">tiff2pdf</a> (the downloadable
        demo version adds an advertising line to the converted PDF); another
        shareware "tiff2pdf" can be found in the <a href="http://www.davince.com/">Davince PDF suite</a> (full version; Windows only; registration after 30 days)</p></li>
<li><p>the (non-free) Acrobat Exchange conversion facilities</p></li>

<li><p>APIs: <a href="http://www.pdflib.com/">PDFlib</a> (Aladdin license)
        now has a fast passthrough mode as well, you can use the 
        <code>image.c</code> example to start with; other APIs are <a href="http://www.stillhq.com/">Panda</a> (also C, GPL; that would be my choice if I wrote 
        c42pdf now) and <a href="http://www.reportlab.org/">ReportLab</a> (Python).</p></li>
<li><p><a href="http://www.blasum.net/holger/wri/comp/data/image/g4tweak/">g4tweak</a>
(GPL) some g4-compressed scanned image manipulations
(experimental, eg inverse functionality to c42pdf)

</ul>
<h3>... but I am on Windows ! </h3>

<ul>
<li><p>Imagemagick and tiff2pdf have links to the 
        Windows binaries directly on the above-mentioned respective homepages</p></li>
<li><p>the libtiff-tools can be currently found as 
        executables at stillhq.com, e.g. 
        http://www.stillhq.com/libtiff/win32/3.5.4/tiffcp.exe and
        http://www.stillhq.com/libtiff/win32/3.5.4/tiff2ps.exe</p></li>
<li><p><a href="http://sourceforge.net/project/showfiles.php?group_id=1897&release_id=38186">Ghostscript</a>, recommended: gs651w32.exe</p></li>
<li><p><a href="http://gnuwin32.sourceforge.net/packages/netpbm.htm">Netpbm</a>, 
        (1) download netpbm-9.19-bin.zip. 
        (2) You also need <a href="http://www.cygwin.com/">Cygwin</a> follow <code>Install
        Cygwin now</code> to run in (it's fun), during the installation
        routine please enable (check) TIFF support.
        (3) And might want to get the <a href="http://www.stillhq.com/libtiff/win32/3.5.4/libtiff.dll">libtiff only</a>, pls put
        it into an executable path.</p></li>

<li><p>of course doing the compile yourself is always an option, but pls 
        drop me a mail to c42pdf@ffii.org if any of these links becomes
        outdated</p></li>

</ul>
<h3>So many programs ! Which one shall I choose ? How shall I use it ? (Christoph) </h3>
<p>        There are several tradeoffs between ease of installation of 
        programs and ease of the actual program use you can strike. </p>
<h4>        I: One-step conversion:</h4>
<p>                Either use <a href="http://c42pdf.ffii.org">c42pdf</a>, command:
<pre>

                     c42pdf sample.tif
</pre>
</p>
<p>                This will create a file <code>sample.pdf</code>. In cases it gives you an error message,
                a more versatile tool is the <code>convert</code> command from 'ImageMagick':
<pre>
                        convert sample.tif sample.pdf
</pre>
</p>
<p>                You will be pleased to find out that convert also works 
                in this intuitive way for many other formats. </p>

<p>                Big limitation with ImageMagick (tested: version 5.3.9): the resulting PDFs 
                use the <code>packbits/RunLengthDecode</code> 
                compression which for some b/w images is about factor 10 less
                efficient than CCITT4. During conversion, the image data
                is represented as bitmap, so it is rather memory intensive
                and slow ('time convert sample.tif sample.pdf': 2.105s in 
                contrast to: 'time c42pdf sample.tif': 0.063s). </p>
<p>                Even if you are frustrated when ImageMagick just takes too
                long on your machine (and proceed to the next step) keep
                in mind that it is a very cool tool for raster image
                conversion in general (e.g. GIF to PNG), only that its
                black-white PDF image generation is not so good.</p>
<h4>        II.1: Ghostscript-based two-step conversion (eg c42pdf doesn't work, output size is an issue):</h4>
<p>                use <code>tiff2ps</code> from the libtiff-tools in connection with
                <code>ps2pdf</code> from Ghostscript (ps2pdf is just a shell script
                with reasonable params to gs):

<pre>
                        tiff2ps -a sample.tif &gt; sample.ps
                        ps2pdf sample.ps
</pre>
</p>
<p>                My benchmark (BTW, on a 137 MHz [237 bogomips] cpu, with the
                sample.tif included in the source distrib of c42pdf) for this
                is 0.387s for first plus 0.630s for the second step.</p>
<p>                I have so far not found a way of piping this (though I 
                may be overlooking something obvious) so you would probably
                want to write a script like::</p>
<p>                unix/Cygwin bash:
<pre>
                        #!/bin/bash
                        basename=${1%.tif*}
                        tiff2ps -a $1 &gt; ${basename}.ps &amp;&amp; \
                                ps2pdf ${basename}.ps &amp;&amp; \
                                rm ${basename}.ps

</pre>
</p>
<p>                to be run as: <code>script sample.tif</code>
                It is of course also possible to enclose
                said script into a condition such as:
<pre>
                        if ! test "c42pdf $1"; then script $1; fi
</pre>
</p>
<p>                so that c42pdf is used where it works fast and fine
                and sth else where it doesn't - this setup would
                emulate the behavior www.fastio.com's <code>tiff2pdf</code>.</p>

<p>                DOS shell, not tested:
<pre>
                        tiff2ps -a %1.tif &gt; %1.ps
                        ps2pdf %1.ps 
                        move %1.tif.pdf %1.pdf
                        del %1.tif.ps
</pre>
</p>
<p>                to be run as: <code>script sample</code> (<em>without</em> tif ending)</p>

<p>                Output paper format and resolution:</p>
<p>                On my localized linux system, the default of ps2pdf
                is to write A4 format, but this may be different on another
                machine. You can easily add an argument to ps2pdf for the 
                papersize, e.g.:
<pre>
                        ps2pdf -sPAPERSIZE=a4 sample.ps
</pre>
</p>
<p>                Other options for PAPERSIZE could be legal,b5, etc .. </p>
<h4>        II.2: Alternative: c42pdf-based two-step conversion:</h4>
<p>                use <code>tiffcp</code> from libtiff-tools in connection with <code>c42pdf</code>,
                first use tiffcp (small and fast) to bring your TIFFs into
                adequate format:

<pre>
                        tiffcp -c g4 -r 100000 sample.tif sampleg4.tif
</pre>
</p>
<p>                Then run <code>c42pdf</code> on the new file:
<pre>
                        c42pdf -o sample.pdf sampleg4.tif 
</pre>
</p>
<p>                unix/Cygwin bash:

<pre>
                  #!/bin/bash
                  basename=${1%.tif*}
                  tiffcp -c g4 -r 100000 $1 /tmp/temptif.tif
                  c42pdf -o ${basename}.pdf /tmp/temptif.tif
</pre>
</p>
<p>                DOS shell: 'SCRIPT.BAT':
<pre>
                  tiffcp -c g4 -r 100000 %1.tif %1g4.tif
                  c42pdf -o %1.pdf %1g4.tif
                  del %1g4.tif
</pre>
</p>
<p>                to be run as: <code>SCRIPT SAMPLE</code> (<em>without</em> tif ending!)
                The "del" command will obviously delete a file named 
                <code>sampleg4.tif</code> so you should make sure that there 
                is no file <code>sampleg4.tif</code> in the current directory if 
                you have a file <code>sample.tif</code>.</p>

<h4>        III. Three-step conversion (advanced users):</h4>
<p>                Another obvious way to go is to use <code>tiffcp</code> for the 
                conversion of any TIFF document to a format c42pdf 
                can definitely process, then do the fast throughput
                via c42pdf and then run ghostscript for FlateDecode 
                and optimized page trees on it - so in effect c42pdf is 
                used as intermediate link between the most powerful tool
                for reading TIFFs and the most powerful tool for 
                producing PDFs. In comparison with the aforementioned 
                second two-step conversion the trick is by directly jumping into
                PDF directly the poor Postscript compression can be avoided.</p>
<p>                unix/Cygwin bash:
<pre>
                  #!/bin/bash
                  basename=${1%.tif*}
                  tiffcp -c g4 -r 100000 $1 /tmp/temptif.tif
                  c42pdf -o /tmp/temptif.pdf /tmp/temptif.tif
                  gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite \
                        -sOutputFile=${basename}.pdf /tmp/temptif.pdf 
</pre>
</p>
<p>                My benchmark for this is 0.751s on a 466 bogomips CPU for 
                (III) as opposed to 1.121s for (II.2) on that CPU on the 
                tiny sample.tif. On larger files the ratio even improves 
                to about 50% savings in computing power and disk 
                activity of III vs II.2.</p>

<h4>        Remark on choosing compression modes in Ghostscript (advanced users)</h4>
<p>                Ghostscript version 5.50 produces a <code>/CCITTFaxDecode PDF</code>,
                whereas Ghostscript version 6.50 produces <code>/FlateDecode
                PDF</code>. </p>
<p>                The compression efficiency of <code>/FlateDecode</code> seems slightly 
                (usually about 0-15%) better than <code>/CCITTFaxDecode</code> on random 
                documents, so this is nothing to worry about.</p>

<p>                If for whatever reason you want <code>CCITTFaxDecode</code> you can 
                either deliberately use
                version 5.50 of Ghostscript, since explicit control by 
                the <code>-dAutoFilterMonoImages=false</code> or 
                <code>-dMonoImageFilter=/CCITTFaxDecode</code> seems not to be operational 
                in version 6.50, or apply a trick posted to <a href="http://groups.google.com/groups?hl=en&threadm=B65308C7.6CBA%25fulvio%40omniacom.net&rnum=1&prev=/groups%3Fq%3DMonoImageFilter%26hl%3Den%26rnum%3D1%26selm%3DB65308C7.6CBA%2525fulvio%2540omniacom.net">comp.lang.postscript</a></p>
<p>                <code>Ghostscript</code> also should be able to do it directly, but I 
                haven't figured out how yet ;-) - pls tell me if you know 
                how to do it because it is </p>

<h5>         Stuff that I had tried too (but not really recommended): </h5>
<p>                TIFF generation with tifftopnm:
<pre>
                  tifftopnm sample.tif &gt; sample.pbm; 
                  pnmtops sample.tif &gt; sample.ps
</pre>
</p>

<ol>
<li><p>664s for the first, 0.742s for the second step. </p></li>

</ol>
<p>                Limitation: this sometimes results in black-white inversion.</p>
<p>                convert <em>any</em> TIFF to something else (eg non-multistripped 
                TIFF), </p>
<p>                <code>netpbm</code> tools:
<pre>
                        tifftopnm sample.tif &gt; sample.pbm
                        pnmtotiff -g4 -rowsperstrip 100000 sample.pbm &gt; sample.tif      

</pre>
</p>

<ol>
<li><p>606s for the first, 0.791s for the second step.</p></li>

</ol>
<p>                This creates a TIFF image with all (well the first 100000 
                which is sufficient for paper sizes less than 10 meters ;-) ) 
                rows in one strip.</p>
<p>                Limitation: this results in black-white inversion. I have also
                not figured out how to do this on multipage TIFFs. </p>
<h3>Various routes from single-page to multipage (Hartmut)</h3>
<p>        All of the above-mentioned conversion from TIFF to PDF work fine where
        input files are already multipage TIFFs. When you want to merge
        single page input files into multipage TIFFs conceptually you have 
        three options when to do it: <em>before</em> conversion, <em>during</em> conversion
        and <em>after</em> conversion.</p>

<p>        <em>Before</em> conversion should be a piece of cake with libtiff and 
        can definitely be done with the <code>-adjoin</code> option of <code>convert</code> but
        if we are converting anyway, why do one useless conversion more?</p>
<p>        <em>During</em> conversion: either use the <code>c42pdf</code> <code>-l</code> option for converting
        lists of files (see its documentation) if that is good enough for you
        or slightly adapt our 'tiff2ps'-><code>ps2pdf</code> two-step conversion process.</p>

<p>        A reasonable way for doing this (due to the bulkiness of postscript
        it is probably better to delay merging into the second step) 
        could be:
<pre>
                        #!/bin/bash
                        if [$# -le 2]
                        then 
                                echo "Usage: miff2pdf outfile infiles..."
                                exit 1
                        if
                        if [ -e tmpdir ]
                        then
                                echo "remove tmpdir manually"
                                exit 1
                        fi
                        outfile=$1
                        shift
                        mkdir tmpdir
                        for i in $@
                        do
                                tiff2ps -a $i &gt; tmpdir/$i
                        done
                        cd tmpdir
                                gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite \
                                        -sOutputFile=../$outfile $@
                        cd ..
                        rm -rf tmpdir
</pre>
</p>
<p>        My benchmark is 2.7s for running this for sample.tif and a copy of it,
        sample2.tif. Please do not forget to add the <code>-sPAPERSIZE</code> to gs if you 
        want to control that. </p>
<p>        <em>After</em> conversion: not the best way to do it (one conversion more
        to do than <em>during</em>) but should be explained in case somebody 
        just delivers you PDFs, so this is about concatenating PDFs ... </p>

<p>        The (recommended) fast way is to use Ghostscript:
<pre>
                gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite \
                        -sOutputFile=output.pdf sample.pdf sample.pdf
</pre>
</p>
<p>        Benchmark: 1.224s for that command. Use <code>-sPAPERSIZE</code> where needed.</p>
<p>        If you want to add bookmarks or document information, this is easy,
        see section below: bookmarks and other pdfmarks.</p>
<p>        A more playful way is to use eg <a href="http://www.etymon.com/pj/">pjscript</a> , a working script for concatenation would be:

<pre>
                #concat.pjs: A simple concat pjscript. http://www.etymon.com/pj/
                #invoked: pjscript concat.pjs infile1 infile2 outfile
                println "Concatenating..."
                #Command line args are stored in the vars 'arg0', 'arg1', etc.
                =file arg0
                readpdf
                =file arg1
                appendpdf
                =file arg2
                writepdf
                println "Done."
</pre>
</p>
<p>        time pjscript output.pdf sample.pdf sample.pdf 4.329s</p>
<p>        For multiple arguments let's write a little java program based on the 
        same PJ library (LGPL):
<pre>
                import com.etymon.pj.*;
                import com.etymon.pj.object.*;
                import java.io.*;
                public class PjConcat {
                        public static void main (String [] args) {
                                if (args.length &lt; 2) System.out.println
                                  ("Usage: PjConcat outfile infiles ...");
                                else try {
                                  Pdf pdf = new Pdf (args[1]);
                                  int filesno = args.length - 1;
                                  for (int i=2; i&lt;=filesno; i++) 
                                    pdf.appendPdfDocument(new Pdf(args[i]));
                                  pdf.writeToFile(args[0]);
                                } catch (Exception e) {
                                  e.printStackTrace();
                                }
                        }
                }       
</pre>

</p>
<p>        time java PjConcat output.pdf sample.pdf sample.pdf 6.175s
        If you are interested in detailed PDF parsing look at PJ's 
        Pdf.appendPdfDocument as well as the pjscript source 
        for a good point to start learning or if you are more C-oriented
        PandaLex (http://www.stillhq.com/).</p>
<p>        Or use something ready-made like <code>pdcat</code>, (expiring) demo versions at 
        pdcat <a href="http://pdf.glance.ch/eval/CLT/Win/pdcat.zip">(win)</a>, <a href="http://pdf.glance.ch/eval/CLT/Linux/pdcat.gz">(linux)</a>, <a href="http://pdf.glance.ch/eval/CLT/Sun26/pdcat.Z">solaris</a></p>
<p>        Other approach to <a href="http://ktmatu.com/info/merge-pdf-files/">joining PDFs</a>.</p>

<h3>Image size of PDFs</h3>
<p>        This will mainly concern engineering drawings.</p>
<p>        Image size in PDF 1.1 and 1.2 is <a href="http://www.pdfzone.com/resources/tips/tip0031.html">limited</a> to 3240x3240 units, in PDF 1.3 it is limited to 14,400x14,400 units. <a href="http://partners.adobe.com/asn/developer/acrosdk/docs.html#filefmtspecs">PDF</a> 1.4 (in appendix
        C) gives the same number of 14,400x14,400 as a limitation 
        of Acrobat Reader. Accordingly, Acrobat Reader as of version 5.05 was
        unable to display a sample scan of 13,568x42,438 pixels, whereas
        that scan could be displayed by ghostview. </p>
<p>        If you plan to convert a whole repository of legacy TIFFs it would be 
        wise to use <code>tiffdump</code> on some of these if there are headers containing
        document metadata. Though this seldom occurs in practice you'd better
        at least check. You can also use <code>tiffcp</code> to check for unknown headers.</p>

<h3>Free OCR ?</h3>
<p>        As an alternative to use <code>Acrobat Capture</code> in some cases you might
        be interested in looking at <a href="http://jOCR.sourceforge.net">GOCR</a> or <a href="http://altmark.nat.uni-magdeburg.de/~jschulen/ocr/index.html">here</a> .</p>
<h3>Bookmarks and other pdfmarks (Hartmut) ?</h3>
<p>        By going through a Postscript stage you can utilize the pdfmark
        kludge for postscript (well documented by Thomas Merz, <a href="http://www.pdflib.com/pdfmark/">pdfmark 
        Primer</a>").</p>

<p>        The cleanest way to this is to create another small file e.g.
        called "pdfmarks".</p>
<p>        Into it we write something like:
<pre>
                [ /Page 1 /View [/XYZ 0 842 1.0] /Title (1stpage) /OUT pdfmark
                [ /Page 2 /View [/XYZ 0 842 1.0] /Title (2ndpage) /OUT pdfmark
                [ /PageMode /UseOutlines /DOCVIEW pdfmark
</pre>
</p>
<p>        <code>/OUT</code> is outline, a bookmark in pdfmarkspeek.
        The last line makes sure bookmarks are displayed on startup.
        And you might want to add Document info as well:
<pre>
                [ /Title (A guide to TIFF-PDF conversion)
                  /Author (Holger Blasum)
                  /Creator (lousy software)
                  /Keywords (who knows)
                  /ModDate (D:20011004101012)
                  /DOCINFO pdfmark

</pre>
</p>
<p>        Now you just invoke ghostscript with the infile plus the new "pdfmarks"
        file:
<pre>
                gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite \
                -sOutputFile=withmarks.pdf withoutmarks.pdf pdfmarks
</pre>
</p>
<p>        This adds pdfmark annotations to an existing PDF document.
        You can also use multiple documents, it actually doesn't matter
        when ghostscript receives the additional information in pdfmark.
        And of course "withoutmarks" can also be in Postscript format.
        Use -sPAPERSIZE where needed.</p>
<p>        For much more detail see the above-mentioned pdfmark Primer (written
        at a time when gs had not yet supported pdfmark (an Acrobat Distiller
        "standard") and pdfmarks had to be embedded in PS but that is 
        irrelevant here). </p>
<h3>Single files to single files: Any way to convert multiple input files (all files in a directory) into individual output files with the same name (new extension) (Greg) ?</h3>

<p>        Converting all files in a directory can be achieved at 
        the operating system's shell level:
<pre>
                Unix solution::

                        for A in *.tif; do c42pdf $A; done

                DOS/Win solution: ("MS-DOS command line prompt")::

                        for %f in (*.tif) do c42pdf %f
</pre>
</p>
<p>        Another, more powerful approach (e.g. for converting all *.tif in
        an entire drive recursively (including subdirs) that is also robust 
        for "long" filenames)) would be e.g. to use (download) the (Cygwin) 
        GNU tools (http://www.cygwin.com/) and run from the freshly installed 
        Cygwin bash shell located in the directory you want all subdirs of 
        to be converted:
<pre>
                find . -name '*.tif' -exec c42pdf '{}' ';'
</pre>
</p>
<h3>I'd rather convert <em>from</em> PDF <em>to</em> TIFF. </h3>

<p>        This is an easy one, use Ghostscript:
<pre>
                gs -q -dNOPAUSE -dBATCH -sDEVICE=tiffg4 -r300 -sPAPERSIZE=a4
                -sOutputFile=mypdf.tif mypdf.pdf
</pre>
</p>
<p>        <code>-r</code> is the resolution, not using it would default to 204x196 
        (standard FAX resolution) for tiffs.</p>
<p>        If you'd prefer multistrip <code>-dMaxStripSize=8192</code> would be an option.</p>

<p>        Or simply use ImageMagick: <code>convert mypdf.pdf mypdf.tif</code>.
        Or use pdfimages (Xpdf) to convert to JPEG, PBM pr PPM.</p>
<h3>I still have questions on PDF</h3>

<ul>
<li><p><a href="http://www.stillhq.com/cgi-bin/getpage?area=ctpfaq&page=index.htm">PDF FAQ</a></p></li>
<li><p><a href="http://www.pdfzone.com/">PDFzone</a> has a catalogue of PDF software 
                vendors and distributors</p></li>
<li><p><a href="http://www.stillhq.com/">Stillhq</a> and <a href="http://www.pdflib.com/">Thomas Merz</a> offer commercial consulting</p></li>

</ul>
<h3>Acknowledgments: </h3>
<p>       To Christoph Schulze, John A Kunze, James Y Hope, Hartmut Pilch, Greg Falvo, Jimmy Ngo, Dan Cogliano, Bill Gilchrist, Eric Smith for comments and questions.</p>

== GhostScript Examples ==

Ghostscript PDF to PNG/TIF


gswin32c.exe -dNOPAUSE -dBATCH -r300 -sDEVICE=pnggray -sOutputFile="test.png" "TestFile.PDF"
gswin32c.exe -dNOPAUSE -dBATCH -r300 -sDEVICE=pnggray -sOutputFile="c:\test.png" "c:\internet\Eudora\attach\12-30-2014 6-57 PM.pdf"

copy "c:\internet\Eudora\attach\12-30-2014 6-57 PM.pdf" .\

gswin32c.exe -dNOPAUSE -dBATCH -r300 -sDEVICE=pnggray -sOutputFile="test.png" "test.pdf"


the map file cidfmap was not found

gswin32c.exe -s OutputFile="test.png" "test.pdf"

gswin32c.exe -q -dNOPAUSE -sDEVICE=pngalpha -r300 -dEPSCrop -sOutputFile=test2.png test.pdf

gswin32c.exe -q -sOutputFile="test3.png" "test3.pdf"

gswin32c.exe -dNOPAUSE -dBATCH -r300 -sDEVICE=pnggray -sOutputFile="test.png" "TestFile.PDF"

gswin32c.exe -dNOPAUSE -dBATCH -sDEVICE=pnggray -sOutputFile="test.png" "test3.pdf"

* http://hublog.hubmed.org/archives/001875.html
* http://newsgroups.derkeiler.com/Archive/Comp/comp.lang.postscript/2006-06/msg00089.html