This mask is independent of any other graphics planes within ImageWorks and may only be edited within the DEM Editing panel.
The ``Show Mask'' toggle button will either enable or disable the display of the graphic mask. While the graphic mask is not visible, the Mask Editing operation buttons such as Trace, Polygon, and Fill will be disabled.
Note: only the visibility of the graphic mask is controlled by the Show Mask toggle. Any operations which use the graphic mask will still work correctly even though the mask itself is not visible.
To select a new mask colour, click on the current colour. Then, select the new colour from the menu presented.
The ``Clear Mask'' button will clear the entire graphic mask. The ``Trace'', ``Trace&Close'', ``PolyLine'', and ``Polygon'' buttons allow an area to be outlined, later to be filled. These operations are activated by selecting the button and then using the left mouse button to move the cursor over the DEM, outlining an area of interest. While one of these operations is active its button will appear depressed.
The "PolyLine" operation creates a new line segment connected to the last, for each Drag sequence. The "Polygon" operation acts the same as the "PolyLine" operation, but closes the polyline to form a polygon when you terminate polygon mode.
"Trace" mode creates a series of short line segments as the cursor is dragged around with the left mouse button depressed. "Trace&Close" mode is similar to Trace mode, except that it closes the traced polygon when the left mouse button is released.
The "Fill@Cursor" button is used to flood fill an outlined area on the mask. Select this function then move the cursor to the area and click the left mouse button to initiate the fill. This function is deactivated after each left mouse button click; if the right mouse button is used the function remains active and another area can be filled.
Note: ensure the areas to be filled are CLOSED polygons before filling them; otherwise, the filling will leak out and fill the entire image. The "Trace&Close", and "Polygon" operations are specifically designed to create areas guaranteed to contain fill operations.
The "Fill Failed@Cursor" button is used to flood fill an area of failed values. Activate this function, then move the cursor to a part of the DEM with failed values. Click the left mouse button to initiate the fill. This function is deactivated after each left mouse button click; if the right mouse button is used the function remains active and another area can be filled.
The "Fill all Failed" button is used to flood fill ALL of the areas with failed values in the entire DEM.