Geometric Computer Vision for Rolling-shutter and Push-broom Sensors

iii Almost all cell-phones and camcorders sold today are equipped with a CMOS (Complementary Metal Oxide Semiconductor) image sensor and there is also a general trend to incorporate CMOS sensors in other types of cameras. The sensor has many advantages over the more conventional CCD (Charge-Coupled Device) sensor such as lower power consumption, cheaper manufacturing and the potential for on-chip processing. Almost all CMOS sensors make use of what is called a rolling shutter. Compared to a global shutter, which images all the pixels at the same time, a rolling-shutter camera exposes the image row-by-row. This leads to geometric distortions in the image when either the camera or the objects in the scene are moving. The recorded videos and images will look wobbly (jello effect), skewed or otherwise strange and this is often not desirable. In addition, many computer vision algorithms assume that the camera used has a global shutter, and will break down if the distortions are too severe