We can only hope that every book we receive will have been manufactured perfectly straight. It would make our jobs easier and it would make our customers happier as well. Unfortunately, sometimes the books that we receive are not always assembled symmetrically. Sometimes they are printed strange, with pages and words slanted, manufactured at a weird angle, etc. Some are slightly off, some are extremely off. Sometimes the words are printed right next to the seam causing the words to curve inward.
It can be hard to notice this slant if you have never looked for it. Over the years all of us read so many books and most of us never pay attention to it. With eReaders, it's much easier to notice the slant inside of a crooked book. Here is a screenshot of what a skewed page looks like when the book is manufactured incorrectly:
This is a screen capture of the PDF.
The red lines are straight lines and the green lines highlight the path of the slanted text.
We try our best to work with a book when it is slanted, but sometimes it is beyond fixing without using special operations. This is why we offer our High Quality Touch Up Option (HQT). The first benefit of the HQT Option is the Angle correction. You can see the sample here:
The red lines are straight lines for reference and the green lines highlight the path of the slanted text.
There are other benefits to the HQT Option. Due to the angle correction of the HQT Option, the OCR output is much more accurate. Also, the HQT Option allows OCR for over 40 languages and it compresses the file making the file much smaller. For anyone looking for the highest possible OCR, we always recommend selecting the HQT Option, because it can make a big difference on OCR accuracy even when a book's pages are minorly slanted.