Menus

Collections

Open Collection

Open an Image Collection. See the section on Collections and QuickStart for more details.

Merge Collections

Select two collections and merge them into a single collection.

Recent Collections

A listing of the five most recently used Collections.

Close Collections

Close the current collection.

Exit

Close all windows, and terminate TerraLook. The user is prompted for confirmation.

File

Open File

Open a raster or vector file, and add it to the current view as a new layer. For files with a greater than eight bit data type, min/max values will be computed for scaling purposes. The resulting layer will be assigned the name of the source file.

Save Shape Layer As

Brings up a file selector for entry of a filename to save the active vector layer to. The file saved to will be in ESRI Shapefile format. ESRI Shapefiles can only support one type of geometry per file (point, line, area) so if the active layer has a mixture, only one of the types (the first encountered) will be saved. Feature attributes are only saved if they are described by a schema on the layer, as is the case with vectors loaded from a shapefile.

Save Project

Save the current work session as a Project file (with a .opf extension), a convenient way of returning to the session.

Save View As Image

Save the visible layers in a view to a file.

Create New View

Creates a new TerraLook view window with an independent set of data layers, and makes it the current view.

Close this View

Close the current window. If this is the last main display window for this TerraLook process the user is prompted if they want to exit the whole process.

Print View

Launches the Printing Dialog for printing the view contents.

Recent File List

A list of recently opened files is maintained in this menu. Selecting one is equivelent to doing a File->Open, and entering the displayed name.

Edit

Undo

Undoes the last undoable operation. Currently only the various vector editing operations are undoable. View changes, layer property changes and addition or deletion of layers are not undo-able. The undo stack is not bounded, and so in theory many undo steps are available; however, certain operations, like destruction of undoable layers results in clearing of the entire undo stack.

Drawing Toolbar

Toggle the Shapes editing Toolbar on/off.

Enhancement Toolbar

Toggle various toolbars on/off.

GIS-RS Toolbar

Toggle various toolbars on/off.

Preferences

Launches the application preferences panel for viewing, and modifying application wide preferences.

Layers

Layer Manager

Toggle the Layer Manager on/off for manipulating view layers. Same as clicking on the button on the Iconbar.

Create Shape Layer

Click to create a new shape layer for digitizing into. Same as clicking on the button on the Layer Manager.

Attributes Table

Click to launch a dialog to edit and manipulate attribute data associated with a Shape file. The dialog is not currently further documented.

Classify Layer

Click to launch a dialog for applying a pseudo-color classification based on attribute data associated to a shape file. The dialog is not currently further documented.

Plot Points from Data

Click to enter data as a point layer, either directly from the keyboard or from a .txt or .csv file. The dialog presented is documented here.

Draw

Point

Activate the Point Drawing Tool. Same as clicking on the button on the Iconbar.

Line

Activate the Line Drawing Tool. Same as clicking on the button on the Iconbar.

Rectangle

Activate the Rectangle Drawing Tool.Same as clicking on the button on the Iconbar.

Polygon

Activate the Polygon Drawing Tool.Same as clicking on the button on the Iconbar.

Ellipse

Activate the Ellipse/Circle Drawing Tool. Same as clicking on the button on the Iconbar.

Text Label

Activate the Label Drawing Tool.Same as clicking on the button on the Iconbar.

Make Arrowhead

Draw an arrowhead on the currently selected line shape. Same as selecting a line shape, then clicking on the button on the Drawing Toolbar.

Image

Enhancement

Linear

Perform a linear stretch enhancement on the active raster layer. Does nothing if a raster layer is not selected in the layers dialog. Same as clicking the button on the Toolbar.

Equalization

Apply a histogram equalization enhancement LUT to the active raster. This is a non-linear constrast stretch intended to flatten out the post-enhancement histogram. See the GvRasterLayer::equalize() method in pymod/gview.py for details on the algorithm used. Does nothing if a raster layer is not selected in the layers dialog. Same as clicking the button on the Toolbar.

Logarithmic

Perform a logarithmic stretch enhancement. The enhancment lut is recomputed to map the minimum to zero, the maximum to 255 and intermediate values based on logarithmic scaling. Same as clicking the button on the Toolbar.

Window Enhancement

Recompute the last enhancement (linear, equalize, logarithmic) based on pixels currently visible in the view. The scaling min/max and enhancement are recomputed. In 3D mode substantial numbers of pixels not actually visible in the view may be included in the calculation. Same as clicking the button on the Toolbar.

Revert to None

Remove any greyscale enhancement LUT (such as applied by the equalize icon) from the active raster layer. Does nothing if no raster layer is selected in the layers dialog. Note that a linear scaling stretch will still be in effect for non-eight bit data. Same as clicking the button on the Toolbar.

3D Visualization

Brings up a dialog for selection of a drape and elevation raster. They are added to the current view as a 3D image, and the view is placed in 3D mode. The tool is documented here.

Compose RGB

Use this tool to compose RGB composite images from raw, single band raster data. The tool is not currently further documented.

Band Classification

Use this tool to perform ISODATA and MAXLIK classifications on collections of single band raster data. The tool is not currently further documented.

FloodFill

Use this tool to make corrections on classified satellite images. The dialog is not currently further documented.

Image Correction

Use this tool to make corrections on classified satellite images using a slightly different interface. The dialog is not currently further documented.

Merge Images

Opens a dialog to merge two or more images. More than one raster must be loaded in the active view.

Calculator

Click to launch a dialog for performing raster calculations on image files. Currently supported functions include NDVI, band addition, multiplication and division. The dialog is not currently further documented.

Raster Calculator

Click to launch a dialog for performing raster calculations on image files in a different interface. Currently supported functions include NDVI, band addition, multiplication and division. The dialog is not currently further documented.

WMS Tool

Click to launch an interface to access remote data. An internet connection is required. The dialog is not currently further documented.

Python Shell

Launches a python shell to permit command line manipulation of data in TerraLook. The dialog is documented here.

View

New View

Launch a new view.

Cascade Views

Cascade all open views.

Set Projection

LatLong

Set the view to an un-projected Lat-Long Projection.

UTM

Set the view to an un-projected UTM Projection.

Set Background Color

Changes the background color of the active view. Three options are available on the menu:

White, Black (the default) and Custom. Clicking on the Custom entry will bring up a color selection dialog, from which you can set a custom color.

Full Screen

Hides the menus and iconbar in an attempt to provide more screen real estate. A small button appears on the bottom corner of the active view: click on this button to end the full screen state. You can also call or end the full screen by using options provided on the RightClick PopUp menus.

Help

Help

Displays application help. Note that online help is displayed as HTML files, and TerraLook needs access to an HTML viewing application. On Windows the default system HTML viewer is used. On Unix various well known browsers are searched for (ie. Netscape, Mosaic). The user can customize this in the application preferences panel.

The help topic for most dialogs can be launched directly by hitting F1 after clicking on the dialog.

Web Page

Displays the TerraLook web page.

Readme

Displays the TerraLook ReadMe.

About

Display TerraLook information, and credits.