title: Image formation by back-projection: a reappraisal.
abstract: The theory of image formation by simple summation of an object's projections, without further processing, is considered. Calculations are presented of the resultant image from a point, a rectangle, an annulus, and three rotationally symmetric objects. The general features of these images are discussed and it is postulated that for many objects of interest a limited compensation for edge unsharpening would suffice to produce recognition of the objects.
mesh_terms: D014054:Tomography / Q000379:methods*