Recent Advances in Space-Variant Deblurring and Image Stabilization

The blur caused by camera motion is a serious problem in many areas of optical imaging such as remote sensing, aerial reconnaissance or digital photogra phy. As a rule, this problem occurs when low ambient light conditions prevent an imaging system from using sufficiently short exposure times, resulting in a blurred image due to the relative motion between a scene and the imaging system. For exam ple, the cameras attached to airplanes and helicopters are blurred by the forward motion of the aircraft and vibrations. Similarly when taking photographs by hand under dim lighting conditions, camera shake leads to objectionable blur. Producers of imaging systems introduce compensation mechanisms such as gyroscope gim bals in the case of aerial sensing or optical image stabilization systems in the case of digital cameras. These solutions partially remove the blur at the expense of higher cost, weight and energy consumption. Recent advances in image processing make it possible to remove the blur in software. This chapter reviews the image processing techniques we can use for this purpose, discusses the achievable performance and presents some promising results achieved by the authors.