With the release of UniPDF v3, the library included support for optimizing PDFs, composite fonts (Unicode characters), digital signatures and, a powerful text and image extraction feature. The adoption of Unicode characters now allows the library to handle the processing and creation of more complex PDF documents that contain Unicode text and symbols. Some minor updates of v3 were styled paragraphs, invoice generation, table of contents and many more that you can read about in the v3 press release.
The ability to optimize (compress) PDF output was an important update and also a difficult one. It involves a multi-step procedure, which is explained briefly in the following points:
- Combine duplicate objects and streams
- Combining indirect objects to compressed object streams
- Reducing resolutions of images
- Higher compression of images and objects