Wide Dynamic Range Technologies: For mobile imaging sensor systems

This article presents several wide dynamic range (WDR) technologies for CMOS image sensors. In photography, dynamic range is the range between the maximum and minimum measurable light intensities. The varying degree of light intensity depends on the device that is used as a capture device, which decides the overall performance of a dynamic range of an imaging sensor. WDR technology increases the dynamic range of an imaging sensor by physically improving a pixel performance or digitally applying multiple exposure times for each pixel. This enables users to easily take a picture in case of a backlit, indoor, or tunnel scene, all of which contain mixed high- and low-light conditions. We will review WDR technologies and describe our efforts on a mobile imaging sensor system considering pixel technology and digital technology supporting the performance of a WDR imaging sensor.