A system detects an application attempting to invoke an administrative utility on a target application for installation of software. In an embodiment depth map frames are captured by a mobile depth camera at over 20 frames per second and used to dynamically update in real-time a set of registration parameters which specify how the mobile depth camera has moved. The resulting cost savings make it possible for the provider of services to share with the consumer of services a substantial percentage of the payment that the provider receives from a third party payer. Relative methods are also disclosed. This is accomplished by measuring the current through the LED, and also by knowing the duty cycle of the pulse width modulator drive signal to the LED.