2-d Semi-adapted Local Cosine/sine Transform Applied to Seismic Data Compression and Its Eeects on Migration

Local cosine/sine basis is a localized version of co-sine/sine basis with a smooth window function. It has orthogonality and good time and frequency localization properties. Adaptive local cosine/sine basis is a best-basis based on a cost-functional obtained from an overabundant library of cosine/sine packets. In this paper, we apply the 2-D semi-adaptive (time-adaptive or space-adaptive) local cosine transform (2-D semi-ALCT) to the SEG-EAGE salt model synthetic data set for compression. Nearly all the important features of the data set can be kept very well even in the case of the high Compression Ratio (CR=40:1). Using the reconstructed data from the highly compressed ALCT coeecients (CR=40:1) for migration, we can still obtain a high quality image including subsalt structures. We also nd that the window partition, generated by the 2-D semi-ALCT, is adapted to the characteristics of seismic data sets.