What is the best type of marker to detect with OpenCV and how can I find the 2D location near real-time on the iPhone? -

I used an IPhone to use OpenCV to detect 2D locations in the predefined marker's iPhone camera. Writing app (only one). What is the best type of marker? Circle? Square? Colour? What is the fastest way to recognize that marker? In addition, the detection algorithm needs to run near real time.

I have tried to locate the OpenCV circle, but I got 1 FPS (640x480 image):

  Mat gray; Of vector & lt; Vec3f & gt; Circles; Find CGPE Search Largest Chakra (Eye Image * Image) {Mutt IMG (Image); CvtColor (IMG, Gray, CV_BGR2GRAY); // Smoothen it, otherwise many false circles can be detected Gaussian Burl (Gray, Gray, CV :: Size (9, 9), 2, 2); HoughCircles (Gray, Circle, CV_HOUGH_GRADIENT, 2, Gray Row / 4, 200, 100); Double radius = -1; Size_t ind; (Size_t I = 0; i Circulo. Size (); i ++) {if (circles [i] [2]> radius) {radius = circles [i] [2]; Ind = I; }} If (IND == -1) {Return CGPointMake (0, 0); } And {Return CGPointMake (circles [Ind.] [0], Circles [Ind] [1]);   
 
   
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 Perhaps you can try some specific color markers, then color filtering Keep in mind, with another, specific oriented texture, the object is also a good option.