Interactive processing: Geometry manipulation

Introduction

SEP has a long history of writing interactive viewers for regularly sampled multi-dimensional volumes (Clapp et al., 2008; Biondi and van Trier, 1993; Ottolini, 1982; Clapp, 2010). It has also dabbled in interactive processing using a range of platforms from Sunview (Claerbout, 1991) to Xtpanel (Cole and Nichols, 1993,1992) to AVS (Clapp and Biondi, 1994). These attempts have met with limited success because they often did not provide a significant advantage over batch processing in terms of efficiency or ease of use.

The last 15 years have seen a significant change in the relative speeds of disk, memory, and compute power, with the former lagging far behind. In addition the size of seismic data volumes has grown by at least an order of magnitude. This brings into question the paradigm of running a batch program, QC'ing with a viewer a small percentage of the volume, then repeating with new parameters or proceeding to the next step. A different paradigm is to put the viewer as the central player, minimizing the amount of disk IO in exchange for redoing computations. This paradigm can be particularly effective in manipulating headers, which generally involve a low number of operations for each byte read accessed.

In this paper I introduce a new tool, qthead, for interactive header manipulation. The application allows the user to perform all of the basic header key functions in SEP3D (Biondi et al., 1996). The user works on a random subset of the headers, rotating, windowing, and gridding until a satisfactory result is achieved. The application stores all of the commands. These commands can then be applied to the entire volume, greatly reducing the required I/O.

Interactive processing: Geometry manipulation