My question is about using the highlighter on certain pdf documents in preview, but I guess rooted more directly in the differences between pdf documents.
I accept the fact that the pdf has to be a text pdf (or something like that) to be able to use the highlighter in preview. I understand this to mean that if I were to scan the page of a book as a pdf, preview would just recognize this as an image pdf, but not text, and therefore not allow me to use the highlighter to select text within the scanned page.
What I have noticed in reading different papers for my classes is that for a scanned book, sometimes I can use the highlighter tool and sometimes I can't. For one of the documents that I can use it on, the scan was done really poorly - not very straight and creased pages at some points. This understandably messes up how straight preview draws in the highlighting, but I still have the ability to highlight. On other documents with very straight scans, I can't even select any text with the highlighter.
Does this mean that there is an inherent difference in how things are scanned and/or saved as pdfs?
Thanks in advance for any help.🙂
I accept the fact that the pdf has to be a text pdf (or something like that) to be able to use the highlighter in preview. I understand this to mean that if I were to scan the page of a book as a pdf, preview would just recognize this as an image pdf, but not text, and therefore not allow me to use the highlighter to select text within the scanned page.
What I have noticed in reading different papers for my classes is that for a scanned book, sometimes I can use the highlighter tool and sometimes I can't. For one of the documents that I can use it on, the scan was done really poorly - not very straight and creased pages at some points. This understandably messes up how straight preview draws in the highlighting, but I still have the ability to highlight. On other documents with very straight scans, I can't even select any text with the highlighter.
Does this mean that there is an inherent difference in how things are scanned and/or saved as pdfs?
Thanks in advance for any help.🙂