1. A method to image objects, the method comprising: generating to a memory, a time series of a plurality of X-ray projections of an object acquired under limited angular conditions with a flat-panel detector, wherein the plurality of X-ray projections are suitable for tomosynthesis reconstruction; generating a plurality of virtual X-ray projection images, wherein the virtual projection images are interpolated projection images, generated from a trilinear method using multivariate interpolation on a 3-dimensional tensor product grid with arbitrary and non-overlapping grid points in each of a plurality of dimensions, which approximates the value of an intermediate 3-dimensional point within the local axial rectangular prism linearly from data on lattice points; and displaying the plurality of virtual X-ray projection images in the time series.