Photography is an ever-advancing technology: pixels are getting more densely packed, colors are going deeper, and light sensitivity is going higher. But the camera standard dynamic range largely remains less than the full brightness range of a natural scene. In the days of film cameras people have used the multiexposure high dynamic range imaging to capture the full dynamic range although only limited for static scenes. However, with digital photography, the exposure index can be spatially multiplexed on a sensor, which adapts the essence of the multi-exposure technique for single-image high dynamic range imaging. A sophisticated postprocessing is required; and existing techniques either lose final image resolution or take a long time to run. In this paper, we propose a novel method for this postprocessing: we use a robust global optimization method and a fast edge-preserving interpolation technique for full resolution exposure-multiplexed high dynamic range imaging.