We have developed new algorithms for denoising 2D or 3D poststack seismic-amplitude data that use simple edge-preserving smoothing operators in the frequency-offset domain. The algorithms are aimed to attenuate random and coherent noise, to enhance the signal energy and lateral continuity, and to preserve structural discontinuities such as faults. The methods consist of fitting the frequency slices of the data in the spatial dimension by means of low-order polynomials. We use an overlapping window operator to select the fitting parameters for each point of the slice from the neighborhood with minimum fitting error to provide edge preservation. Various synthetic examples and a field data set are used to demonstrate the strengths and limitations of the algorithms. The denoised outputs indicate enhanced edge preservation of seismic features, which reflects clearer details of semblance attributes.