Patent ID: 11941897
Assignee: FOTONATION LIMITED
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 11:
12. A vehicle occupant monitoring system, OMS, comprising:
an image acquisition device with a rolling shutter image sensor, said device being configured to selectively operate in either: a full-resolution image mode where an image frame corresponding to the full image sensor is provided; or a region of interest, ROI, mode, where an image frame corresponding to a limited portion of a limited number of rows of the image
sensor is provided, wherein the image sensor is rotated through ninety degrees such that the rows of the image sensor run upward when the OMS determines that an image of the vehicle occupant's body region needs to be acquired for gesture detection, said image sensor comprising an array of pixels, each pixel comprising pixels which are sensitive to at least infra-red light,
at least one infra-red, IR, light source disposed within a cabin of said vehicle and being configured to illuminate at least one occupant of the vehicle;
an object detector configured to receive a full-resolution image from said image sensor and to identify a ROI corresponding to an object of interest within said image; and
a controller configured to obtain an image corresponding to said ROI from said image sensor operating in ROI mode, said controller being: responsive to detecting lighting conditions decreasing, for increasing the exposure time for a subsequently acquired image, unless said
exposure time exceeds a threshold time for illuminating the rows of said ROI with a single pulse of IR light from said IR light source; responsive to said exposure time exceeding the threshold time, for increasing an intensity of said at least one IR light source, unless said increased intensity would exceed a maximum intensity; and responsive to said increased
intensity exceeding a maximum intensity, for increasing a gain for pixels of said image sensor.