Annotation Troubleshooting
Now and then, you will find that a PDF file does not allow you to annotate it with Citavi. Why is this?
Secured PDF files cannot be copied or annotated
If a PDF file is secured, it's not possible to copy text from it or annotate it. Citavi displays a yellow lock symbol in the bottom left of the preview pane if a PDF file is secured.
Solution for secured PDF files: If you want to save quotations from a secured PDF file, you will either have to retype the text or photograph it and use a text recognition program. You can also find ways to remove the protection online, but before you take such a step, you may want to ask yourself why the publisher decided to add the protection in the first place and if you really want to go against the publishing company's wishes.
Scanned texts cannot be copied or annotated
You also can't copy or annotate text if the PDF file contains scanned text. This can happen if you order an article through interlibrary loan. The first page from the library contains text that can be copied, but all other pages are just photographs of the article.
Solution for scanned text: Open the PDF file with a program that can convert scanned images to searchable text (Optical Character Recognition). You can find this feature in the full version of Adobe Acrobat. Alternatively, search for an online service that lets you upload a PDF scan and then download the file with searchable text by using the search terms "online OCR". The text recognition quality can vary widely, and you might need to try a few different providers.
Please note:
Text recognition software usually doesn't deliver 100% accurate results. When you copy texts that have been run through OCR, you may notice that some characters appear incorrect.
Poorly scanned texts cannot be copied or annotated
Occasionally, you'll encounter a scanned text that has undergone OCR but that still can't be annotated. This can happen if the text is not horizontal.
Solution for slanted text: Apply OCR again. A good text recognition program will recognize such problems and will correct the image's orientation.