The newer version of TesseractTesseract (3.03 RC at the time of writing this)(3.03 RC at the time of writing this, in 2014) can do this:
- free, opensource and cross-plarform
- starting from version 3.03 PDF output is available
- CLI software
- multiple languages support
- unfortunately, single image input, so to make a complete document, one must create a batch script to convert each page image to searchable PDF. After that PDF pages should be combined to a single PDF using tools like pdftk.
This is the command:
tesseract -l <lang> input.tif output pdf