A Closed-Form Focus Profile Model for Conventional Digital Cameras

作者：Pertuz Said^*; Angel Garcia Miguel; Puig Domenec; Arguello Henry

来源：International Journal of Computer Vision, 2017, 124(3): 273-286.

DOI：10.1007/s11263-017-1024-8

• Focus measure
• Focus profile
• Camera model
• Camera calibration
• Depth of field

According to the thin lens model, the classic depth of field (DOF) is defined as the distance range at which objects in front of a camera are in focus. However, the thin lens poses important practical limitations for modeling the camera focus due to its dependence on internal parameters, such as the focal length, numerical aperture and effective pixel size. In this paper, a new model for describing the focus of conventional digital cameras is proposed. The focus is modeled as the energy of the point-spread-function of the imaging system and describes the joint effect of defocus, diffraction and digitization. Experiments conducted on different acquisition devices show that the proposed model conforms accurately to the behavior of real systems and out-performs the most similar alternatives in the state-of-the-art. In addition, in contrast to the classic DOF model, the proposed approach can be used to predict the changes in the focus of conventional digital cameras when changing focus, zoom, and aperture by means of a simple calibration process.

• 出版日期2017-9