So far the content appears to be excellent, readable, well structured and not prone to gloss over important implementation detail. You are also likely to learn more than just rendering techniques from this book.
But, the quality of the paper used and the resulting print quality is poor for a book of this price. Pages are slightly warped in places and of such thin poor quality paper that they can crease just by being turned. In fact you don't need to turn pages to see the other side you can see what's printed on the other side through the paper. It reminds me of an illicit cheap replica book or a low-cost "student" paper back edition. This is a particular problem with the nature of the content, in that the value of figure's comparing the image quality of different algorithms is obscured by the overall low quality of all the images. I can understand why this book might have been a challenge to print, high page count, colour images mixed in with the main text but refuse to believe this is the best that can be done.