Texas Instruments Incorporated
WDR imaging with LED flicker mitigation

Abstract:

A method of WDR imaging. Exposure times (ETs) are set for first and second frames for an image sensor to avoid second frame saturating by setting a second ET>1/a PWM frequency applied to an LED illuminating a scene to generate second longer ET pixel data (PD). The first frame has first PD and a first ET<the second ET. A high and low intensity threshold are calculated from a full well capacity. Raw image signals are obtained originating from the image sensor of the scene. Flicker is detected by comparing the first and second frame intensity values to the high and low threshold to determine whether the first PD is flickering data. A WDR merge is performed by selecting weightings from the first and second PD for each pixel including increasing weighting of the second PD for flicker. A final image is formed from the weighted WDR merge.