Low Image Contrast Detection in a Bright Light Interference HDR Scene Using Smart CAOS Camera

Abstract

Proposed and experimentally demonstrated is the linear low contrast detection capability of a smart design Coded Access Optical Sensor (CAOS) camera operating under interfering bright light conditions. This fine contrast imaging capability is delivered by engaging both the silicon CMOS sensor-mode of the constructed smart CAOS camera and deploying spatial filtering within its inherent on/off light routing structure via the Digital Micromirror Device (DMD). The camera uses the CMOS-mode identified non-bright light region of interest to engage the Code-Division Multiple Access (CDMA) CAOS-mode to achieve successful target imaging. Specifically, the low contrast variation (¡ 6 dB dynamic range) test target region of the toy horse target is successfully experimentally imaged within a near 87 dB High Dynamic Range (HDR) scene created by the presence of an external interfering bright visible light source. Applications scenarios that can benefit from the use of the proposed camera include natural bright light conditions surveillance as well as bright laser and LED targeted imaging across medical, industrial and scientific sectors.