Studies have shown that in many organizations 20% of documents are not fully text searchable and won’t be found by SharePoint or Office 365 Compliance Search.
Most commonly these files are Image PDFs or Vector PDFs that originated as scans, faxes or output from design packages.
Aquaforest's Findability Solutions for SharePoint and Office 365 dramatically improve search success by ensuring that Site Collections are fully text searchable.
The trial version of Aquaforest Searchlight allows unlimited auditing which will allow you to determine how many of your PDF files are not fully text searchable.
The trial also allows conversion of a limited number of Image PDFs for testing purposes.
To run in production a fixed price license needs to be purchased from Aquaforest. You will also be charged by Microsoft Azure for the hours the VM is running.