This paper proposes a design scheme of a WDR camera to expand dynamic range of a scene. It captures the scene twice with different exposure time, makes a range-expanded scene out of the 2 frames. The main characteristics of this design are its H/W simplicity and real time operability. It is based on weighted average method, whose weights are computed pixel-base. It saves frame buffer by processing the WDR operation before the interpolation. It uses LUT for computing the weight coefficients and parameters for automatic exposure control, which require relatively simpler H/W elements than other computing units. The proposed design can be used for a wide area of the imaging devices such as digital camera, mobile phone camera, cam coder, vehicle camera and surveillance CCTV camera etc.