OpenCV Expert Needed to write functions optimized for speed

The overall project involves recording and rebroadcasting a video stream, with specialized analytics in between. As part of a larger project, we are looking for a person who is an expert in computer vision type systems to help in the area of motion detection and motion tracking. We are currently using OpenCV in this area, however if you have suggestions for something else that may work better, we will consider it. The environment is Linux. The selected contractor will design and write code in form of a function used by a separate application that control a Pan Tilt Zoom like camera, directing it to where to look for movement on playing surface. We envision the function input being a pointer to an array of images and a selected detection method, with the output being the a) the center of all motion detected, b) right, left, top and bottom of motion detected area and c) direction of motion (this may change depending upon discussion with contractor) Inside the function, using OpenCV or other library there will be a minimum of 2 methods, one will be dependent on object motion detection, the other based on object tracking (more complex). The method used will be selected when the function is initially called an will not change until the full application is restarted. The key part of the function is that it be quick to provide output to other application in order to adjust the viiew to keep moving objects in the frame. Please note that we are only looking for contractor that has EXPERIENCE in Computer Vision type system! Unless you have worked on such systems in the past, please do not bid on the project.