A ``renzogram'' is a technique for displaying velocity information in a cube in a different (better) way than velocity fields. The technique was pioneered by Renzo Sancisi at the Kapteyn Institute in Groningen. A ``renzogram'' overlays a single-level contour map for every channel in a cube over an image (such as an optical image or moment map). The contour map for each channel is displayed in a different colour (typically red-blue, although this can be changed interactively). This has an advantage over velocity fields because it shows multiple peaks in the velocity profile, which a velocity field cannot do.
To load an image, just click (left) on the Images button and select a file. Then click (left) on the Cubes button to load a cube. You enter an absolute contour level in the Contour Level Control window, and click (left) on Apply Parameters. You will soon see the contours over your image. Sliders are provided to change the range of channels and channel skip factor. To change the colours the contours are drawn in (the default is black to white), click (left) on the Contour Colourmap button and manipulate the colourtable in the usual way. Click (left) on Colourmap to manipulate the colourtable for the image.
You can also view a profile (spectrum) of your cube profiles. Just click on the Profile button and a profile window will appear. You will note that the profile is drawn in the same colours as the contours.
A screen snapshot is available
here