rasterelement

Raster element, commonly referred to as a raster cell or pixel, is the smallest addressable unit of a raster dataset. It represents a sample of a real-world phenomenon at a specific location on a regular grid and contains a value that encodes an attribute such as reflectance, elevation, or land cover. A raster image is formed by arranging many raster elements in rows and columns, and a single-band raster has one value per element while a multispectral or multi-temporal raster stores multiple values at each grid location.

In a raster dataset, the grid defines the spatial resolution and extent. Each raster element covers a precise ground area equal to the cell size, which is determined by the spatial resolution. The location of the grid, its alignment with a coordinate reference system, and the overall extent are described by metadata. In multispectral or multi-band rasters, there is a separate value for each band at every grid location.

Data types and handling are important aspects of raster elements. Values may be integers or floating-point numbers, and there is often a designated nodata value to represent missing or invalid samples. Raster data is stored in various formats (for example GeoTIFF, NetCDF, HDF, or proprietary IMG formats), frequently with compression and accompanying metadata such as the CRS, affine transform, and cell size.

Raster elements underpin a wide range of geographic information system (GIS) and remote sensing applications. They enable spatial analyses such as local statistics, map algebra, resampling, and reprojection, and they are foundational to processes that convert real-world phenomena into gridded data for visualization and decision making.