A method of calibration for a plenoptic camera system to determine the true size of an object feature in a light-field image of the object wherein the camera system comprises: an objective lens positioned along an imaging axis intersecting a point in the object； a photosensor positioned for acquiring images of portions of the object and a microlens array positioned in between the objective lens and the photosensor such that each microlens in the array projects a different view of the image formed at the image plane thereby forming an array of elemental images on the photosensor； the method comprising: acquiring an initial image of the object； extracting matching features from any plurality of views derived from a plurality of elemental images forming the initial image； and calculating at least one functional relationship between two or more views having matching features.
