Neighborhood Aggregate

The NeighborhoodAggregate operator computes an aggregate function for a pixel and its neighborhood. The operator can be defined as a neighborhood matrix with either weights or predefined shapes and an aggregate function. For each time step in the raster time series, the operator computes the aggregate for each pixel and its neighborhood.

Types

There are several types of neighborhoods. They define a matrix of weights. The rows and columns of this matrix must be odd.

WeightsMatrix

The weights matrix is defined as an n × m matrix of floating-point values. It is applied to the pixel and its neighborhood to serve as the input for the aggregate function.

Rectangle

The rectangle neighborhood is defined by its shape n × m. The result is a weights matrix with all weights set to 1.0.

AggregateFunction

The aggregate function computes a single value from a set of values. Supported functions are sum and standardDeviation.

Errors

If the neighborhood rows or columns are not positive or odd, an error is thrown.

Parameters

Name	Type	Description	Examples
neighborhood	NeighborhoodKernel	Neighborhood definition applied around each pixel. This can be a rectangular neighborhood or a custom weights matrix.	{"dimensions":[3,3]} {"weights":[[1,0,-1],[2,0,-2],[1,0,-1]]} {"type":"rectangle","dimensions":[3,3]}
aggregateFunction	NeighborhoodAggregateMethod	Aggregate function applied across the neighborhood values.	"sum"

Sources

Name	Type	Description
raster	RasterOperator	An operator that produces raster data.

Examples

{
    "type": "NeighborhoodAggregate",
    "params": {
        "neighborhood": {
            "type": "rectangle",
            "dimensions": [3, 3]
        },
        "aggregateFunction": "sum"
    },
    "sources": {
        "raster": {
            "type": "GdalSource",
            "params": {
                "data": "example"
            }
        }
    }
}