Yes OCR can be used to reduce the file size of a PDF as pdf is image based and OCR converts that image into text which reduces the size of the file. This may make great change to the file size and it can reduce the overall burden of data.
Other uses of OCR are: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 52. 53. 54. 55.