Gesture recognition is a tool that can be used to control any common device by effortless hand gestures. The goal behind gesture recognition is to minimize the gap between the digital world and the physical world. This wireless interaction creates this algorithm much friendlier to the user. This paper tells the technological characteristics of gesture-controlled user interface (GCUI), and also recognizes its trend and application. It is observed that GCUI now offers practical opportunities for application-specific areas, especially for people who are not comfortable with input devices which are commonly used. This project implements an advanced image processing application to recognize the gestures and process them in real time for better and reliable results. To recognize the gesture the ratio of the percentage of area not covered by hand in the convex hull is found. The optimized code is easily integrated with a Raspberry-Pi processor or microcontroller for a fully functional robot.