To have a fast and accurate scan,  the QUALITY OF MARKERS plays a vital role. Each image are broken down into detection points depending on the contrast and complexity of the design. The presence of multiple points of detection helps our app detect the object quickly and accurately.  It will be good to make your makers as complex and with as much contrast as possible. In our testing, we realized by adding WORDS and QR CODES to our markers significantly increases the amount of detection points thus reducing the amount of time required for the app to recognize the object accurately. The following are examples of the marker ratings from 1 star (poor rating) to 5 Stars (excellent rating).  

Click to Read More on Optimizing Target Detection and Tracking Stability