Overlay Vectors

This topic describes how to use the Vector Parameters dialog to overlay vectors on an image in an ENVI Classic display group. See Vectors for the recommended method for creating and edting vectors in ENVI.

Use Overlay > Vectors to overlay vector layers on an image, to control the appearance of the vectors, and to interact with the vector attributes. You can also use ENVI Classic’s interactive vector functions to edit and query attributes associated with shapefiles and to create your own vector files and attributes.

Use the Vector Parameters dialog to:

• Control the appearance of vector layers
• Add new vectors
• Export vector layer coordinates for use in image-to-map registration
• View, edit, and query vector attributes

When you overlay vectors on an image, you can plot them in the Image window, Zoom window, and/or Scroll window. You can also edit existing vectors or add new vectors in any of the three display group windows.

• To select which window to use for editing or adding vectors, select the Window radio button at the top of the Vector Parameters dialog for the desired display group window.
• To select the display group windows to plot the vectors in, select from the Image, Scroll, or Zoom check boxes at the bottom of the Vector Parameters dialog.

If you have two display groups open at the same time, do not attempt to edit the same vector layer in both displays.

Display group windows with vector overlays have many options which you can access by right-clicking in the display group window chosen for the overlay (Image, Scroll, or Zoom). The options available in the right-click menu changes depending on the cursor mode selected.

If you have many display groups open and the Vector Parameters dialog associated with the current display group is hidden behind other windows, right-click anywhere in the display group and select <Find Vector Parameters>.

Show and Hide Layers

In the Vector Parameters dialog, an asterisk next to a layer name indicates that the layer is On (default), which means it is plotted when you click Apply. If an asterisk is not next to a layer name, then the layer is Off.

To show or hide vector layers, double-click on the layer name in the Available Vector Layer list.

You can optionally use a right-click menu to turn layers on and off:

• Right-click on the layer name in the Available Vector Layers list, select Select Active Layer, and click on a layer to make it the active layer.
• Right-click again and select the Active Layer Off/On.

Set the Current Layer Color

• The color shown next to Current Layer in the Vector Parameters dialog is the color of the currently selected layer. Use the color button to change the color. To apply the selected color to the selected vector, click Apply.
• If your vectors display in a Vector window, use Edit > Edit Layer Properties to change the color.
• The color shown in the Current Highlight box is the color to use to highlight a vector when it is selected in a vector attributes table. Use the color button to change the color.