A method has beenproposed for blindly estimating the Point Spread Function (PSF) of video data. The PSF's of the images in a sequence are assumed to be of compact support and hence admit FIR modeling. The zeros (roots) of the Optical Transfer Function (OTF) - i.e. the Fourier transform of the PSF - are first estimated by locating the singularities of the magnitude of the cross power spectrum. These roots are then used for spectrum factorization leading to complex polynomial approximation of the OTF. It has been shown that a 2 0 spectrum can be factorized under the assumption of local isotropy around the roots.