Optimizing Prepress PDF for Size
SAGE PDF Enhancer (SPE) is both a command line (server) tool and a GUI tool for reducing the sizes of the PDF documents, especially those produced by Mac OS X/Quartz. In addition, you can also set the Document Info and Open Actions associated with the PDF as well as applying standard Acrobat security/encryption.
The Windows versions of this product (server and desktop) are available for purchase from JRA, an authorized reseller.
SPE can be used in two modes - lossless and lossy. The difference is the use of the image processing features of SPE to reduce the resolution of images and/or recompress them using lossy algorithms such as JPEG. The default for SPE is lossless - we want to make sure that we never damage your data without your permission. To enable the image processing module, you will need to specify one of the .spe configuration files (eg. screen.spe, eBook.spe, etc.) that contain the settings for image scaling and/or recompression. The study below uses screen.spe.
SPE can also be used on non-Quartz PDF's but will not achieve the same levels of compression when using lossless mode due to the usually better optimized documents produced by other tools.
However, SPE first examines the document(s), and can apply a number of possible size reduction techniques based on what it finds. These techniques are both general in nature, as well as specific to certain applications (such as InDesign) therefore allowing it to reduce files in the most optimal ways possible. You can also choose to enable the image processing options in order to reduce file size.
JRA conducted three tests on different PDF document sets that were intended for web delivery when they were created, and then we further compressed them with SPE. The size reductions were 43%, 31%, 58%, averaging 44%. This makes a difference in performance, as you will see when you open the links below.
We used the server version of SPE to apply uniform compression to sets of PDF files that were not originally uniform in their compression. As you can see in the third test, one file was not reduced at all (it was already optimized), while another was reduced from 4 MB to 1 MB.
SPE is a great tool for applying uniform compression to collections of PDF files, thereby optimizing for web delivery. This is a great companion product to SearchPDF, because it eliminates performance bottlenecks that would be caused by PDF documents that are needlessly large and therefore too slow to load.
At the same time that SPE compresses the files, it can also assign other attributes to the PDF files in batch mode, such as security settings and metadata fields, so that the optimized PDF are completely ready for web-based search and retrieval.
We plan on implementing SPE on the server, using web submittal pages to collect PDF files from remote sites. After being uploaded, they will then be automatically optimized with SPE.
SPE gives you a big performance boost when serving PDF on the web!
FIRST TEST
In the following test using 16 newspaper pages, the screen.spe configuration file was used.
The total file size reduction is 43%.
Loss of quality is negligable.
Click on a size to open that file
PDF Filename
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Distiller - Print Quality Output (bytes)
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Print optimization using SPE (bytes)
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Screen optimization using SPE (bytes)
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a17-01.pdf
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a17-02.pdf
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a17-03.pdf
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a17-04.pdf
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a17-05.pdf
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a17-06.pdf
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a17.07.pdf
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a17-08.pdf
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a17-09.pdf
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a17-10.pdf
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a17-11.pdf
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a17-12.pdf
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a17-13.pdf
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a17-14.pdf
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a17-15.pdf
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a17-16.pdf
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Total Size
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8,309,576
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5,510,135
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4,721,317
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Percentage Reduction
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100%
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66.3%
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56.8%
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SECOND TEST
In this second test, four complete multipage newspaper issues, created with Print-Quality output in Acrobat Distiller, were compressed using the screen.spe configuration file of Sage PDF Enhancer.
The total file size reduction is 31%.
Loss of quality is negligable.
Click on a size to open that file
PDF Filename
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Distiller - Print Quality Output (bytes)
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Screen optimization using SPE (bytes)
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a17.pdf
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dids.pdf
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prov.pdf
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star.pdf
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Total Size
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35,242,167
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24,378,590
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Percentage Reduction
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100%
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69%
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THIRD TEST
In this third test, we have taken a set of product brochures in PDF format from this website: http://www.hydacusa.com/broch.htm, from the Accumulators section. The 10 PDF documents were produced with Distiller 4.0 on the Mac. We compressed them using PDF Enhancer with the screen.spe profile to obtain the results listed below.
The total file size reduction is 58%.
Loss of quality is negligable.
Click on a size to open that file
PDF Filename
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Distiller - Print Quality Output (bytes)
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Screen optimization using SPE (bytes)
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accumdataheet.pdf
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AccumInstruct.pdf
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charging.pdf
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Dampeners.pdf
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Diaphram.pdf
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genaccum.pdf
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mounting.pdf
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permgaugeblock.pdf
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Piston.pdf
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SAF.pdf
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Total Size
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10,839,185
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4,531,918
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Percentage Reduction
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100%
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42%
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FOURTH TEST
In this fouth test, we have taken a set of product brochures in PDF format from this website: http://www.bentley.com, from the search feature. The 9 PDF documents were produced with a variety of software over time. We compressed them using PDF Enhancer with the screen.spe profile to obtain the results listed below.
Click on a size to open that file
PDF Filename
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Existing Output (bytes)
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Screen optimization using SPE (bytes)
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csen0196.pdf
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csen0595.pdf
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csen0996.pdf
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csen1196.pdf
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q194mdl.pdf
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q196mdl.pdf
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q197mdl.pdf
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q494mdl.pdf
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web_bg.pdf
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Total Size
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9,426,720
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5,957,050
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Percentage Reduction
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100%
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63%
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