The text is fine for reading, but illustration work starts to run dark, pixellating and/or losing shades of grey. It's the problem of making a copy of a copy. Unfortunately, the resulting quality of these books is not as high. We essentially digitally re-master the book. Also, a few larger books may be resampled to fit into the system, and may not have this searchable text background.įor printed books, we have performed high-resolution scans of an original hardcopy of the book. However, any text in a given book set on a graphical background or in handwritten fonts would most likely not be picked up by the OCR software, and is therefore not searchable. The result of this OCR process is placed invisibly behind the picture of each scanned page, to allow for text searching.
Most older books are in scanned image format because original digital layout files never existed or were no longer available from the publisher.įor PDF download editions, each page has been run through Optical Character Recognition (OCR) software to attempt to decipher the printed text. These products were created by scanning an original printed edition.