Preferred Detection Algorithm?


I have written my first application using OpenCV! The program performs the following three steps:

Step 1: Reads in the RAW image (black circle on a tan background)
Step 2: Converts RAW image to grayscale image.
Step 3: Performs Threshold (i.e. binary filter) to turn the image black/white

See below image for reference:

My question is what is the preferred detection algorithm for finding this circle? It will always be a circle but will be of varying sizes. My goal is to detect the circle and report back the center of mass (X,Y) coordinates. I would like a fast algorithm as I would like to perform all the above steps + the detection algorithm in less than 33ms (i.e. camera provides 30 frames per second).


Greg Maxwell