A gesture-based user interface method and corresponding apparatus that includes a light source configured to irradiate light to a user, an image sensor configured to receive light reflected from the user and output a depth image of the user, an image processor configured to recognize a user gesture based on the depth image output from the image sensor, and a controller configured to control the light source and the image sensor such that at least one of an optical wavelength of the light source, an optical power level of the light source, a frame rate of the light source and a resolution of the depth image is adjusted according to a gesture recognition mode.