Analysis and characterization of a plenoptic camera for industrial applications

Conventional cameras are instruments to get images of real objects. The photography is gotten collecting on a film, through a lent, the light spread by the objects of the scene. In the digital cameras, that last is substituted by an array of sensors (CCD) which allow to measure the amount of light for each pixel. In order to understand the physics behind the plenoptic camera, we have to define: the focus and the depth of field. In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge; the depth of field (DOF) is the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. In the conventional cameras in order to increase the depth of field, we need to reduce the diaphragm, however in this way we reduce the resolution of the image. The evolution of those digital cameras is the plenoptic camera. It allows to increase the depth of field without any reduction of the diaphragm. With one shot we are able also to refocus the gotten imagine, or change the point of view, or increase the depth of field without reducing the resolution. So the capability of this camera is to re-capture the light distribution entering from the world, which in the conventional cameras is lost: so this camera is able to measure not just our 2D photographs of the total amount of the light at each point on the photosensor, but rather the 4D light field measuring the amount of light traveling along each ray that intersects the sensor. The purpose of capturing the additional two dimensions of data is to allow us to apply ray-tracing techniques to compute synthetic photographs flexibly from the acquire light. The overall concept is to re-sort the rays of light to where they would have the terminated if the camera had been configured as desired. In order to capture 4D light field about a scene, plenoptic camera, or light field camera, is equipped of an array of individual lenses. This lens arrangement means that multiple light rays can be associated to each sensor pixel and synthetic cameras can then process the information. The physics linked to the plenoptic camera is explained in details in the following chapters. The aim of the work is to understand the most important physical principles linked to plenoptic camera and the estimation of the accuracy in practical applications using a 3D chessboard designed throught Solidworks software and printed throught 3D printer. The study of the accuracy is computed through a designed algorithm which is able to locate, on the virtual representation of the object, two points useful for the computation of the distance. In addiction, the design algorithm is able to perform some transformation on the virtual object. At the end of the computations, it gave as results some graphs which are explained in the final part of the work.