Choose a file for OCR: Click the Open button to open the original file. Open your PDF file that you want to extract: Click the Save button to save the file to your device folder. Open Wonder share PDF Converter Pro on your device to see the file details such as the PDF filename and the number of pages. Choose a conversion level for your PDF: Click the Change button to change the conversion level for your PDF files. For OCR to work, your PDF files must be in the correct character sets such as: BMP, IDF and JP2. The file icon should show up when you change your conversion level — to see your conversion progress click Convert in the top left side.