Question

How to avoid image quality loss while exporting a document as a searchable PDF?

Answer

In order to preserve the original image quality in OCR Editor follow the instruction below:

1.  Go to File > Options > Format Settings > PDF and check off Use MRC compression:
   
2. In Image quality change the setting to Best quality or Custom Quality:
   
   While adjusting the custom quality, change Quality parameter to Quality loss not allowed:
   

Note, that OCR Editor rasterizes vector images on the import stage. If you need to preserve the vector graphic follow the instruction from this article: Adding only text layer to PDF document in PDF Editor