Hello!
Looks like Alfresco (Community 201707) have some trouble with searchable word selection into OCRed pdf files?
See picture.
See some shift of selection, not really under the real words and letters. Its unusable if need select and copy/paste some word from OCR pdf.
Its a bug (please confirm somebody) or can be tuned for normal look?
On picture also Chrome and Adobe Reader window with same file and normal selection directly under letters. So its looks like not OCR engine problem but Alfresco rendering.
Its the bug of the tool which you are using and not of alfresco.For example , if you are using pdfsandwich for performing ocr than its bug of pdfsandwich. Not sure which tool you are using.
Basically when you perform the OCR, what every tool does is creating a text from the pdf/image and put it on behind the what we visually looking at.So it often happens that the coordinates become bit of wrong.
OCR depends on the quality of image as well.It is totally depends on the capability of the OCR Tool.