Lab 5 Flashcards
In terms of foreground and background values, what’s the difference between the Expand and Shrink tools?
In terms of foreground and background values, the difference between the Expand and Shrink tools is as follows:
a. Expand: foreground zones are allowed to expand into the background zones.
b. Shrink: foreground zones are allowed to be replaced by cells in the background zones
How does the selection of number of neighbors affect Majority Filter outputs?
Using four for the number of neighbors will retain the corners of rectangular regions.
Using eight neighbors will smooth the corners of rectangular regions.
What’s the difference between Majority Filter and Boundary Clean?
Boundary Clean uses expanding and shrinking of zones to replace cell values and smooth zone edges. Majority Filter uses a majority kernel to re-assign cell values. Generally speaking (as evidenced by the input/output graphics in each of the tool documentation pages), the output of the Majority Filter more closely resembles the input.
In the Flow Direction tool output, what direction coding does 16 stand for?
If the direction of steepest drop was to the left of the current processing cell, its flow
direction would be coded as 16.
How is a flow direction raster used by the Basin tool?
The drainage basins are delineated within the analysis window by identifying ridge lines
between basins. The input flow direction raster is analyzed to find all sets of connected
cells that belong to the same drainage basin.
In your own words, what does the Region Group tool do?
Region Group identifies unique contiguous regions of cells. Contiguity can be contingent upon or regardless of the input raster values.
When using the Nibble tool, what happens to areas of NoData in the mask raster?
Cells that are NoData in the input mask raster define which cells will be nibbled. Any
locations in the input raster that are not within the mask area will not be nibbled, and so the output value for them will be the same as the input value.
