Perform OCR text extraction. This requires you have the
pdf_ocr_text( pdf, pages = NULL, opw = "", upw = "", language = "eng", dpi = 600 ) pdf_ocr_data( pdf, pages = NULL, opw = "", upw = "", language = "eng", dpi = 600 )
file path or raw vector with pdf data
which pages of the pdf file to extract
string with owner password to open pdf
string with user password to open pdf
passed to tesseract to specify the languge of the engine.
resolution to render image that is passed to tesseract::ocr.