We’re excited to announce compression improvements across our products, including the PDF Optimizer API of the Adobe PDF Library (C++, C#, and Java), the PDF Optimizer command-line application (Windows and Linux 64-bit). Fair warning: the improvements are significant, and the results are substantial (some may even say they are mind-blowing, but we’re not here to put words in your mouth).
With these updates, we are releasing the compression power that was once hidden and only readily accessible to the PDF experts out there who knew which knobs to tune by opting into the right settings. Now, you don’t have to be a PDF expert to experience the power of maximum compression, and you can get great compression results ‘out of the box’ without having to tweak any settings. In other words, you can get the best results without having to be bogged down with knowing PDF technical details. Win-win!
As part of this compression-driven focus, we now deliver three new compression-focused profiles known as compressionLow, compressionMedium, and compressionHigh in the command-line tool. The Medium profile is your best bet to get great compression results across just about any kind of PDF document. It’s the profile to use if you’re not sure exactly which settings you need other than great compression. It makes very smart choices about where you can trade-off some loss for substantial file size compression. The Low profile is best suited to users who need moderate compression but can’t afford much loss. The High profile is best suited to users who need the maximum possible compression and are ready to accept modest losses.
When we say ‘loss,’ we mean that there is some information in a PDF that can be inconsequential to visual fidelity and cross-compatibility that during compression, you are technically losing, but the document remains the same in terms of what you see and what you can do with it. There are other types of information in a PDF, particularly in images, that can be compressed in a lossy fashion (meaning there is some loss of information or richness of pixel information) but to the human eye the loss is barely noticeable. Knowing this, we can take steps to modify a PDF to substantially reduce its size.
During our research and development phase, we decided to test the competition (including competitors’ SDKs, applications, and online services) and are very proud to say we’re delivering the best PDF compression technology available on the market today. We took a collection of various PDFs featuring different challenges (different page counts, file sizes, compression levels, PDF features, PDF versions, etc.) and ran them through our previous public release. We then worked step-by-step on improvements, and the result is in aggregate a 20% improvement using the Medium profile. Individually, however, results can become even better. Some files that were previously uncompressible are now compressible by over 90%!
Existing users of the Adobe PDF Library will notice that in this new release, some optimization parameter default values have changed. This was intentionally done to lead to the best result, but often we found users would need to significantly tweak settings to reach their desired compression level. Now, we’ve taken the guesswork out of the picture for users by choosing smarter default settings. For specialized purposes you may need to disable individual settings, but we realized part of delivering a world-class PDF software experience means taking the pressure off our customers to become PDF experts. That’s just too much pressure.
The real beauty of this compression power is that it’s fully customizable! If you need to target more aggressive compression or removal options in one scenario you can do so, and in a different scenario you can target more modest settings. This is easy to do with clearly labeled API options at the programmatic level and equally easy to do in the command-line tool using similar JSON profile settings.