This book may helpful, I read it before when I want to realize the viola-jones face detection algorithm on a FPGA. it is "Design for Embedded Image Processing on FPGAs".
And there are also a number of papers that also focus on FPGA implementation of image processing algorithms.
Most of the books that are available in the literature provide either architecture, theoretical background but do not reveal the information towards practical implementation of image or video processing algorithms on FPGAs. The only book that offers substantial information to implement image/video processing algorithms in FPGAs is the "Digital VLSI System Design" authored by Dr. S. Ramachandran, IIT Madras.