I have a situation where I want to convert user supplied single page PDF's to black and white bitmaps in a suitable high resolution for further processing (eventually ending in a proprietary printing solution). All this must run in headless mode.
Due to policital and technical reasons this must be a pure Java library (i.e. no Ghostscript wrapper), and at this point in time we are interested in a royalty-free open source solution but where performance is not very important. If this project is successful we might need an upgrade path to a more performant proprietary library, but not now.
I have had a look around, and found that most PDF-library projects focus on either manipulating or viewing PDF's, but not as much on using it as a render engine - which is the only thing I need - and at least one engine has deliberately crippled the font engine in the Open Source version compared to the commercial version.
Hence, I need a recommendation for a PDF-library:
- Render input files to bitmaps in headless mode.
- All Java, no native code.
- Renders all PDF-files commonly found in the wild (except invalid or incorrectly formatted ones)
- is Open Source with a business friendly license.
- is robust
- is actively maintained
- may be slow or not able to handle more than a few pages (more pages being a limitation lifted in the commercial version)
Suggestions?