If we are not able to extract reference labels from your PDF figures, the problem is likely one of the following.

• Scanned PDFs — The PDFs must have the text inside them and not just images.  We do not perform optical character recognition (OCR) on PDF files. 
  • If you are able to select the text of a ref label in a PDF viewer, then we should be able to extract the text (though see the next bullet point). If you are not able to do select the text, then the PDF is an image without text, and you must use OCR before processing with Patent Bots.
• Incorrect Internal Formatting — Try opening the PDF in a PDF viewer, copying the text of a ref label, and then pasting it somewhere else (e.g., in an email).  If the paste does not work, then the PDF has incorrect internal formatting, and we are not able to extract the text.  Try updating your PDF generation tool and review export settings.
• Unexpected exports from drawing software — By default, most drawing tools should export PDFs with text that we are able to process. PowerPoint and Visio do this by default. If we are not able to find ref labels in a PDF exported from a drawing program, check the export options in the program to make sure that text is included in the export. An image-only export will not work.
• Very complicated PDFs — Very detailed PDFs may exceed our processing capabilities.  If proofreading takes about 1 minute and then you get an error, it is likely that your PDF is too complicated for our processing. We are working on improving this, but in the meantime, you will need to proofread without figures.