1. A method, comprising: receiving, by one or more processors, one or more images depicting at least a portion of a hand; determining pixels within the one or more images corresponding to the portion of the hand in a predetermined portion of a field of view of an image capture device, the portion of the hand having a finger; based on the pixels corresponding to the portion of the hand, identifying a finger position of the finger; determining a direction of the finger based on the finger position; based on the direction of the finger, dynamically modifying a histogram threshold for identifying pixels as corresponding to the portion of the hand; and replacing the portion of the hand and the finger with a graphical interface element aligned with the direction of the finger.