uniDEM supports raster flood filling to quickly collect large areas of similar pixels as defined by these parameters. There are many options to change the layer, the range and the type of flood fill that is performed.

Flood Fill is activated using the Flood Fill tool (Shortcut: F - or - Go to Home, panel Tools).

Type

Selects the raster layer that the flood fill will be occur on. Fills can be performed on DEMs, Imagery and Masks. Supported options are:

• Auto - picks the top layer as the fill type when more than one layer type is loaded in the view.
  The layers are prioritized as follows:
  1. Mask
  2. Imagery
  3. DEM
• DEM - performs the flood fill on the DEM(s) loaded in the view
• Imagery - performs the flood fill on the Imagery loaded in the view
• Mask - performs the flood fill on the Mask(s) loaded in the view

Default shortcut: none

Mode

Specifies the type of floodfill operation that is performed.
Supported options are:

• Tolerance (+/-) - includes any neighbouring pixel within the absolute difference of the Tolerance
• Above - includes any neighbouring pixel that is above the selected seed point
• Below - includes any neighbouring pixel that is below the selected seed point
• Differential (+/-) - includes any neighbouring pixel whose absolute difference is within that Tolerance specified

Default shortcut: none

Tolerance

Defines the tolerance range over which a floodfill can occur.

Default shortcut: none

Action

Determines how the results of the floodfill will be applied to the selection mask.
Supported options are:

• Overwrite - replaces any selection in the mask
• Add - adds to any existing selection in the mask
• Subtract - removes fill pixels from the selection in the mask
• Invert - toggles the selection for any filled point

Default shortcut: None

Connectivity

Specifies the type of floodfill connections that can occur.
Supported options are:

• 8-way - can floodfill up, down, left, right and diagonally
• 4-way - can floodfill up, down, left, right

Default shortcut: none

Max. Radius

Sets the maximum radial distance outward from the clicked point that the flood fill will be performed.
Smaller values increase performance and limit unwanted selections far from the origin of the click.

Default shortcut: none