Surround-view fisheye cameras are commonly used for near-field sensing in automated driving. Four fisheye cameras on four sides of the vehicle are sufficient to cover 360°around the vehicle capturing the entire near-field region. Some primary use cases are automated parking, traffic jam assist, and urban driving. There are limited datasets and very little work on near-field perception tasks as the main focus in automotive perception is on far-field perception. In contrast to far-field, surround-view perception poses additional challenges due to high precision object detection requirements of 10cm and partial visibility of objects. Due to the large radial distortion of fisheye cameras, standard algorithms can not be extended easily to the surround-view use case. Thus we are motivated to provide a selfcontained reference for automotive fisheye camera perception for researchers and practitioners. Firstly, we provide a unified and taxonomic treatment of commonly used fisheye camera models. Secondly, we discuss various perception tasks and existing literature. Finally, we discuss the challenges and future direction.
I. INTRODUCTIONSurround-view systems use four sensors to form a network with overlap regions, sufficient to cover the near-field area around the car. Figure 1 shows the four views of a typical surround-view system, along with a representation of the typical parking use-case. Wide-angle views exceeding 180 • are used for this near-field sensing. Any perception algorithm must consider the significant fisheye distortion inherent with such camera systems. This is a significant challenge, as most work in computer vision focuses on narrow field-of-view cameras with mild radial distortion. However, as such camera systems are more widely deployed, work has been completed in this area. It is the aim of this paper to give the reader an overview of surround view cameras (e.g., image formation, configuration and rectification), to survey the existing state of the art, and to provide insights into the current challenges in the area.In theory, the field-of-view of a pinhole camera is 180 • . However, in practice, due to the practical limitations of the size of the aperture and imager, it is not easy to get over 80 • , as illustrated in Figure 2 (top). Fisheye lenses are commonly used to effectively increase the field-of-view to 180 • or more. It is interesting to note that the term fisheye is a bit of a misnomer, as illustrated in Figure 2 (bottom). Due to the bending of light rays due to refraction at the junction of water and air surface, a large field-of-view of nearly 180 • is compressed to a smaller V. Ravi Kumar, C. Witt, and S. Yogamani are with Valeo. C. Eising is with the Dept. of Electronic and Computer Engineering at the University of Limerick. V. Ravi Kumar and C. Eising are co-first authors.