In this paper, a novel method of improving dynamic range of imaging device is proposed. Unlike multi-capture HDR methods, the suggested method requires only a small modification to existing CMOS imaging sensor. By changing exposure time line by line, one can obtain a multi-exposure image in a single capture of an image. With such captured image, digital image processing algorithms are applied to recover the lost vertical resolution with minimal degradation. This paper will cover overall system issues as well as detailed description of the algorithms applied to recover high dynamic range image.