C++ programming to read image

Hello c开发者_运维百科an someone please guide me with the code for reading an image pixel values using open cv library with c++?

The documentation for opencv is at http://opencv.willowgarage.com/documentation/STRAWMAN/cpp/index.html, with http://opencv.willowgarage.com/documentation/STRAWMAN/cpp/fast_element_access.html showing multiple ways to access image pixels.