Copy+pasting text from PDF results in garbage

Question

I am writing a Master\'s thesis - NLP system. I have one component - extractor.

It is extracting a plain text from PDF files. There are a few PDF files that can not be

Answer 1

If are able to successfully select and copy the text in Adobe Reader -- indicated that the PDF does contain text objects -- but you can't paste the copied text into Notepad without it looking like a bunch of garbage characters, then the problem is probably related to the CMap that the selected text uses.

The PDF specification provides many options for the display of textual content and the related extraction of the text content. A CMap specifies the mapping from character codes to character selectors. The PDF spec outlines some predefined CMaps, but other CMaps can also be embedded.

My guess is that either the CMap for this text is corrupt or that the PDFBox library doesn't support this particular CMap. I suggest trying a different SDK just to see if you get any different results.