Viewit

What Is Viewit?

Viewit is many things, which makes it difficult to describe. It is basically multidimensional image processing software originally developed to handle data from magnetic resonance imaging. Some features of Viewit include:

• projection reconstruction algorithms for MRI data
• multidimensional Fourier transforms
• convolution operators for image smoothing and enhancement
• simple volume rendering functionality

Viewit features a stack calculator paradigm, where each of the four stack registers can contain a multidimensional array. There are about 200 built-in operators, the exact number depends on whether various features, such as numerical libraries, are available on a particular architecture.

One user interface for Viewit is simply the prompt of a Tcl command-line interpreter. No buttons, no sliders, no popup help menus. Becoming proficient in Viewit involves a fairly steep learning curve, but we have found that we are able to accomplish many day-to-day tasks faster with Viewit than with other tools. In particular, the general purpose functionality of Viewit has saved us from the need to write "throw away" C programs that would otherwise be necessary to complete many mundane data preparation tasks.

There is a reference manual and a user's guide that are included as part of the distribution. A "Viewit Cookbook for NMR Imaging and Spectroscopy" by Carl Gregory is also available as NCSA technical report TR012.

Volume Rendering

Viewit features a simple orthogonal projection volume rendering capability that is very useful for visualizing biological data. Example animations can be found in the Biological Imaging Group gallery.

Availability

Viewit source and executables are available here.