Mask
A spatial filter used to limit analysis to a specific area within a dataset (inferred from standard GIS usage).
What is a Mask in GIS?
A mask is a spatial filter used in GIS (Geographic Information Systems) that restricts analysis or visualization to a particular region of interest. It functions as a boundary or stencil, enabling processing or display of just data inside a specified area, such as a polygon or raster extent.
Key Uses of a Mask:
Clip rasters to concentrate only on areas of interest, like a city or watershed.
Distinguishing characteristics in land-use planning or environmental assessments.
Eliminating unnecessary regions outside the mask to increase processing efficiency.
For example, if you have a satellite image of the entire nation but only wish to examine the forest cover in a single district, you can use a mask shaped like that district to extract and examine that area.
In GIS, a mask is a tool that limits spatial operations or visualization to a particular region, enhancing accuracy, efficiency, and focus in geospatial analysis.
Related Keywords
Masking is a technique used in GIS to hide or exclude data outside of a set boundary, hence restricting analysis or visualization to a particular area of interest. Typically, a polygon layer is used to construct a mask, such as a city border or watershed, and only the features or raster cells inside the mask are processed or shown when the mask is applied. This is particularly helpful for boosting map clarity, cutting down on data size, and concentrating on certain regions.
An analysis mask is a raster or feature layer in ArcGIS that is used to define the region that is used for geoprocessing or spatial analysis. Only the cells or features inside the mask boundary are processed by ArcGIS when a mask is applied; anything outside is ignored. This is helpful for increasing accuracy, cutting down on processing time, and concentrating analysis on a particular region of interest.
In ArcGIS Pro, feature layer masking is a cartographic technique that uses the forms of another layer to conceal or mask portions of one layer. By keeping significant elements from being cluttered by overlapping symbols, labels, or patterns, it helps make maps easier to read. Roads can be clearly visualized without losing spatial context, for instance, by hiding building footprints beneath road symbols.
Using a mask layer, the Mask function raster in ArcGIS Enterprise is used to isolate or extract particular regions of interest from a raster dataset. It is helpful for targeted analysis, data visualization, and minimizing processing on unnecessary areas because it conceals undesirable portions and only shows or processes the cells inside the defined mask.