A method of estimating height (2112, 2122, 2154) and tilt angle (2114, 2124, 2156) of a camera system having a 2-dimensional array of image sensors and a plurality of IR illuminators in fixed locations relative to the array of image sensors, comprising, at a computing device (118, 504, 508, 900) having one or more processors (512, 702, 802, 902), and memory (606, 706, 806, 914) storing one or more programs configured for execution by the one or more processors (512, 702, 802, 902): identifying a plurality of distinct subsets (1404, 1602) of the IR illuminators; partitioning the image sensors into a plurality of pixels; for each of the plurality of distinct subsets (1404, 1602) of the IR illuminators, receiving a captured IR image (872, 1606, 2140, 2142, 2144, 2146) of a scene taken by the array of image sensors while the respective subset (1404, 1602) of the IR illuminators are emitting IR light and the IR illuminators not in the respective subset (1404, 1602) are not emitting IR light; using at least one of the captured IR images (872, 1606, 2140, 2142, 2144, 2146) to identify (2164, 2738) a floor region corresponding to a floor (156, 2110) in the scene; forming a light intensity vector including pixels from the captured IR images (872, 1606, 2140, 2142, 2144, 2146) in the identified floor region; and estimating (2748, 2166) a camera height (2112, 2122, 2154) and camera tilt angle (2114, 2124, 2156) relative to the floor (156, 2110) by comparing the light intensity vector to a dictionary, wherein the dictionary includes entries that correspond to the camera system having a plurality of heights (2112, 2122, 2154) and tilt angles (2114, 2124, 2156), wherein each respective dictionary entry includes a respective height (2112, 2122, 2154) and tilt angle (2114, 2124, 2156) above a floor (156, 2110) and includes respective IR light intensity values for pixels in images (872, 1606, 2140, 2142, 2144, 2146) corresponding to activating individually each of the distinct subsets (1404, 1602) of the IR illuminators. identifying a plurality of distinct subsets (1404, 1602) of the IR illuminators; partitioning the image sensors into a plurality of pixels; for each of the plurality of distinct subsets (1404, 1602) of the IR illuminators, receiving a captured IR image (872, 1606, 2140, 2142, 2144, 2146) of a scene taken by the array of image sensors while the respective subset (1404, 1602) of the IR illuminators are emitting IR light and the IR illuminators not in the respective subset (1404, 1602) are not emitting IR light; using at least one of the captured IR images (872, 1606, 2140, 2142, 2144, 2146) to identify (2164, 2738) a floor region corresponding to a floor (156, 2110) in the scene; forming a light intensity vector including pixels from the captured IR images (872, 1606, 2140, 2142, 2144, 2146) in the identified floor region; and estimating (2748, 2166) a camera height (2112, 2122, 2154) and camera tilt angle (2114, 2124, 2156) relative to the floor (156, 2110) by comparing the light intensity vector to a dictionary, wherein the dictionary includes entries that correspond to the camera system having a plurality of heights (2112, 2122, 2154) and tilt angles (2114, 2124, 2156), wherein each respective dictionary entry includes a respective height (2112, 2122, 2154) and tilt angle (2114, 2124, 2156) above a floor (156, 2110) and includes respective IR light intensity values for pixels in images (872, 1606, 2140, 2142, 2144, 2146) corresponding to activating individually each of the distinct subsets (1404, 1602) of the IR illuminators.