Patent ID: 8581974
Filing Date: 2013-11-12
Classification: G06F,G06K

Abstract:
1. A method of performing presence detection, the method comprising: selecting a first image frame as a reference frame, wherein the reference frame is divided into a first grid of zones, and wherein the first grid of zones is associated with a set of reference luminance values; selecting a second image frame as a current frame, wherein the current frame is divided into a second grid of zones, and wherein the second grid of zones is associated with a set of current luminance values; calculating a set of parameters between the set of reference luminance values and the set of current luminance values; determining that at least one of the set of parameters satisfies a pre-determined threshold: in response to the determining, performing one or more actions based at least in part of the at least one parameter and an operating mode of an electronic device; monitoring at least one of a number of positively changed zones, a number of negatively changed zones, a number of changed zones, and a number of changed columns; detecting if a sudden light change has occurred based at least in part on the number of positively changed zones, the number of negatively changed zones, and the number of changed zones; and in response to detecting that the sudden light change has not occurred: