The built-in PDF converters are now the default method for converting PDF files to TIF, replacing the use of "print-to-TIF" printer drivers, which remain as a deprecated option. The built-in renderers handle both portrait and landscape pages and convert to TIF without using the Document Converter print driver. This is usually faster than either Acrobat or Ghostscript and has more options for rendering documents with images and halftones to produce smaller and/or better-quality output TIF files.
Using the Built-in PDF Converters for other Document Types
The CopiaFacts Document Converters for HTML Office and supported Image Documents default to first converting the Document to PDF (which is usually straightforward, fast, and accurate) and then using the built-in PDF converter to create a faxable TIF. We provide a range of optimization options for the PDF->TIF phase.
The built-in PDF converters consist of two elements: each PDF page is first rendered to a color bitmap and then reduced to monochrome for faxing using a standard dithering method. Most of the $image_options keywords affect the second part of the processing, which is also used for HTML documents and for image files. Both parts of the built-in PDF converter are also used for converting Microsoft Office documents, by converting first to PDF and then to TIF. This method is used when automating both Microsoft Office and LibreOffice.
Conversion ‘at send time’'
For small documents, you can select 'at send time' conversion for some document types. This causes documents to be converted on-the-fly, in the COPIAFACTS process, immediately before transmission. This can reduce the document turnaround time because the FS files do not have to be queued for processing in FFEXTERN, perhaps waiting behind very large documents for one-at-a-time processing. This method can be used only for:
•Image documents (JPG, PNG, BMP)
•HTML documents (with or without expansion of embedded variables)
•PDF documents
•Office documents only when converted to PDF using LibreOffice
This conversion method is recommended only for documents of letter, legal, A4 or B4 width (or height, for landscape pages). Other widths will either be truncated (if larger) or scaled depending on the SCALE and SCALE image options. Rendering large documents 'at send time' would seriously reduce throughput because it is preventing a fax channel from sending faxes,
Only one COPIAFACTS fax channel at a time on a node can be used for conversions 'at send time'.. Only one conversion at a time is also done in FFEXTERN, but multiple instances of FFEXTERN on different nodes can be run if conversions do not keep up with faxing.
PDF Document Rendering to TIF
The default built-in PDF renderer is PDFium, Google's renderer developed for the Chrome Browser. This is implemented in a separate supplied DLL and it is not necessary to install Chrome.
An alternate PDF renderer used in earlier CopiaFacts versions is also available, selected by the image option keyword ORIG. If you use on-the-fly PDF rendering (for small numbers of pages only, see above) in COPIAFACTS, it will block 'at send time' conversions in all other channels when one is actively converting.
 | We do not recommend using on-the-fly rendering for documents of more than about half a dozen pages. The Converter Options page must be used to set the page-count threshold above which on-the-fly conversion will not be used. If you know that your users may attempt to convert documents of a hundred pages or more, do not ignore this recommendation. |
The orig option is automatically selected if PDFIUM reports a failure, which typically occurs only if the PDF contains certain rarely-encountered features, or if there is a version mis-match on the PDFIUM DLL. To suppress this fallback to the original renderer, and instead fail the conversion, add an environment variable in FAXFACTS.CFG: $environment * SuppressOrigPDF yes.
Using Libre Office to pre-convert PDF files
If you find some conversion failures are not reported, or that incorrectly rendered documents are sent without detection, CopiaFacts includes a third rendering option: to load the document in LibreOffice and then 'export' it to PDF, as happens with Libre conversion of Office documents. This operation precedes standard PDF rendering and can create a 'cleaned' PDF to pass to the selected (PDFIUM or original) renderer as described above. It is specifed by means of an FS variable PDFLIBRE with a non-empty value. It can only be used for small documents converted 'at send time'; the variable is ignored in the document converter. If this option is required for specific email-to-fax senders, the $var_def command can be specified in a Gateway sender template.
PDF Rendering In summary:
| PDFIUM | The default renderer we use is created by Google and widely used, for example in Microsoft Edge. Only very rare PDF features are unsupported, and are reported when this happens. PDFIUM is updated regularly and the latest current build is in each CopiaFacts release. It is documented as not being thread-safe, but COPIAFACTS v9 (and all FFEXTERN versions) only call it in one thread at a time. It typically creates slightly smaller TIF files than the original rendered used by CopiaFacts. |
| ‘original’ | The original 'QuickPDF' renderer used by CopiaFacts since 2012 was sold to Foxit in 2016 who terminated support, updates and sales shortly afterwards. It has converts most English and European documents very reliably, but has known deficiencies in specific areas, in particular Japanese Chinese, Korean and RTL languages. Rendering failures and unsupported features are not reported as errors. It is not documented as thread-unsafe, but CopiaFacts v9 now only calls it in one processing thread at a time. CopiaFacts uses this original renderer when PDFIUM reports a failure or unsupported feature; this is generally successful, but this fallback can be suppressed. It typically requires more process memory than PDFIUM. |
| Libre Office | From build 9.1.0.367 CopiaFacts includes a PDFLIBRE option (see above) to use LibreOffice to open and export a PDF. When specified, and with LibreOffice installed, this option can preconvert a 'problem' PDF so that either PDIFIUM or the original renderer will no longer fail to render it correctly. We have encountered the need for this only very rarely. |
The available image options for the final stage of conversion to TIF are documented in the Image Rendering Options topic. These options are available to any document conversions via the built-in PDF rendering.
