How can I detect PDFs that have text-searchable content vs. image-only PDFs?

Question

We need to differentiate between OCRed and non-OCRed PDFs, so that we can OCR the PDFs that are not yet searchable.

Thanks for your help.

Tom

Answer

The HasFontResources function can be used to determine if a PDF has any font resources. If the document does not have any font resources then it can be assumed to be an image only PDF (without any text objects).