Editing Product Displays

This lesson provides background information and step-by-step instructions on how to modify various product display characteristics.

Changing the Zoom and Center

The center mouse wheel is the primary way to zoom in or out in an editor. CAVE also provides several different pre-defined zoom factors that you can utilize for those who don't have a mouse wheel or those who desire a fixed display, say for capturing sets of images over the same location. The zoom factors are defined by the map size (in km) in the display panel.

Changing the center point

When viewing a product at one of the default scales (i.e. WFO), the center of the product will always be the center point of that default scale. You can change the map center by panning the image with a left mouse click and drag or by zooming in or out on the map. The location of the mouse pointer when you use the scroll wheel will zoom relative to that location. 

Sampling and Lat/Lon Readout

When products are loaded in an editor, data sampling and the latitude/longitude readout can be toggled on/off using the check box in the right click menu on the editor background (note this is different than right clicking on the product legend or map legend). Leaving sampling on can be distracting, and one best practice is to configure a long-left mouse click to sample on demand without having to use a menu selection.  This will be covered later in the Mouse Settings page and WES Exercise 1 Cursor Sampling and Lat/Lon Readout video.

Changing the Image Color Table of an Image Product

Image products like radar and satellite data use color fills from a color table to indicate the data value for a particular location. Existing color tables can be applied to an image, or the color tables can be edited and saved as new files. Changing color tables manually is temporary unless you save them in a procedure or have your AWIPS focal point assign a new one to the menu loading.

Switching color tables: The Image Properties GUI

Most often, when you want to use a different color table, you just select a new one from the "Imaging" GUI launched by clicking the Image Properties icon on the toolbar or by using Ctrl + I keyboard shortcut. Note you can identify button functionality by hovering the mouse over the button in the toolbar. The Imaging GUI lists the color table for each image product loaded in the main display panel. Clicking on buttons reveals a pull-down menu for the color table options.

Another essential aspect of the Imaging GUI is the Brightness and Contrast controls. These are frequently used to reduce the brightness of displays so you can make other overlays more visible.

The Combined Next Image Load allows you to define paired products that can be faded back and forth. The Interpolate Image and Interpolate Colors will resample and smooth the data, particularly for grid data.

Editing color tables: The Color Table Editor

The Color Table Editor allows you to modify the current color table. The GUI can be a little overwhelming at first because it provides the user with several options to change the color scale.

In the center of the GUI, the current color scale is shown with half-arrows on the top and bottom of the legend. Using the arrows, the operator specifies a range of data to define a color over. Depending on whether the image is a 4-bit or 8-bit/Super Res product, you can either fill that range of data values with a solid color or with a gradient of colors.

The colors used to fill or interpolate the range of values are determined from the two color panels in the GUI. These color selection panels give the user the option of using RGB (Red-Green-Blue) or HSB (Hue-Saturation-Brightness) color models to select a color. In addition to choosing colors, the transparency of the product can also be edited using the Alpha slider bar in the Color Table Editor.

When finished editing the color table, save the changes either to the old Color Table file or to a new file.

Blinking portions of a color table

Blinking the color table is a unique D2D perspective capability that can be useful at times to highlight important data. This can be useful for a warning forecaster who is color blind and who might have a difficult time distinguishing between two different colors used in a color table (even if the scale was specifically designed to mitigate this issue).