Closed-orbit theory provides a semiclassical description of atomic photo-absorption spectra that is similar to semiclassical trace formulas. It is plagued by the same fundamental difficulties: The spectrum is represented as a divergent infinite sum over classical orbits, and the contribution of an individual orbit diverges when the orbit undergoes a bifurcation. While the latter problem can be overcome by uniform approximations, their use prevents the computation of individual semiclassical spectral lines. Taking as examples the hydrogen atom in an electric field and in crossed electric and magnetic fields, I will demonstrate that the technique of harmonic inversion allows the inclusion of uniform approximations into a high-resolution semiclassical quantization, and I will describe the construction of uniform approximations and some pertinent open problems.