INTViewer has a "Lattice Decimation" plugin that allows the creation of "lighter" versions of indexed datasets. Lattice decimation is process that decimates a 3D SEGY seismic volume by specifying a step value in each dimension. This process can reduce the size of a 3D volume by as much as 80%, while still providing full resolution slices.

For example, with a step of 10 for the inline sections, only every tenth inline section is stored. Viewing any of the stored inline sections are identical to the original (full resolution). Here is the dialog that needs to be filled prior to creating a seismic dataset.

The lattice decimation can be automated. The script below is attached at the bottom of this page

For more information on how to automate the transformation of seismic datasets, go to the "Using seismic generators" section of the Python APIs for Seismic Data article.