Interpolation and denoising of high-dimensional seismic data by learning a tight frame

Sparse transforms play an important role in seismic signal processing steps, such as prestack noise attenuation and data reconstruction. Analytic sparse transforms (so-called implicit dictionaries), such as the Fourier, Radon, and curvelet transforms, are often used to represent seismic data. There are situations, however, in which the complexity of the data requires adaptive sparse transform methods, whose basis functions are determined via learning methods. We studied an application of the data-driven tight frame (DDTF) method to noise suppression and interpolation of high-dimensional seismic data. Rather than choosing a model beforehand (for example, a family of lines, parabolas, or curvelets) to fit the data, the DDTF derives the model from the data itself in an optimum manner. The process of estimating the basis function from the data can be summarized as follows: First, the input data are divided into small blocks to form training sets. Then, the DDTF algorithm is applied on the training sets to estimate the dictionary. The DDTF is typically embodied as an explicit dictionary, and a sparsity-promoting algorithm is used to obtain an optimized tight frame representation of the observed data. The computational time and redundancy is controlled by the block overlap of the training set. Finally, the learned dictionary is used to represent the observed data and to estimate data at unobserved spatial positions. Our numerical results showed that the proposed methodology is capable of recovering n-dimensional prestack seismic data under different signal-to-noise ratio scenarios. We determined that subtle features tend to be better preserved with the DDTF method in comparison with standard Fourier and directional transform reconstruction methods.