SummarizeZones

Properties

Property	Characteristic	Dimension	Description
ValueImagePixelType	compulsory, user-defined, default: float	0	The data type of the ValueImage pixels.
ZoneImagePixelType	compulsory, user-defined, default: int	0	The data type of the ZoneImage pixels.
NumDimensions	compulsory, user-defined, default: 2	0	The number of dimensions (image axes) of the input and output images.
IgnoreNodataValue	compulsory, user-defined	1	Whether (IgnoreNodataValue=1) or not (IgnoreNodataValue=0) nodata values (NodataValue) shall be ingnored in calculating zonal summary statistics.
NodataValue	compulsory, user-defined, default: empty	1	The pixel value of the ValueImage to be ignored while calculating summary statistics for a given zone. The NodataValue is ignored if no ValueImage is specified.
HaveMaxKeyRows	compulsory, user-defined	1	Whether (HaveMaxKeyRows=1) or not (HaveMaxKeyRows=0) the number of rows of the output raster attribute table (RAT) shall match the maximum pixel value of the ZoneImage (s. Inputs).
ZoneTableFileName	optional, user-defined	1	The name of the output raster attribute table containing the summary statics for each zone. This parameter is only required if the downstream processing component does not support raster attribute tables or if input is provided to an ImageWriter component and the specified output image format does not support RATs, e.g. TIFF.

Supported Image & Pipeline Features

Feature	Details
Image dimensions	1D, 2D
Multi-band images	no
Pipeline role	process
Sequential processing	yes
Parallel processing	yes
Number of inputs	2
Number of outputs	1

Inputs

Name		Description
ZoneImage	required	A categorical (integer) image depicting discrete areas that share a specific property, e.g. land cover, soil types, adminstrative regions, etc.
ValueImage	optional	Typically a floating point image depicting a property or phenomenon that continuously varies across space, e.g. elevation, temperature, etc.

Overview

The SummarizeZones component summarises the values of the ValueImage within the zones of the ZoneImage. A summary statistic is created for each zone and provided as raster attribute table (RAT) of the output image. If no ValueImage is provided, a summary of the ZoneImage is calculated instead.

Info: The SummarizeZones component recognizes the UserID of its input components as input image names for distinguishing between the ZoneImage and the ValueImage.

Summary Statistics

Attribute	Description
rowidx	The unique zone values detected in the ZoneImage.
zone_id	A 0-based contiguous identifier for each zone.
count	The number of pixels within a given zone.
min	The minimum observed value within a given zone.
max	The maximum observed value within a given zone.
mean	The average value within a given zone.
stddev	The standard deviation for all values within the given zone.
sum	The sum of all values within a given zone.
minX	The minimum observed pixel coordinate along the x-axis (column) for the given zone.
minY	The minimum observed pixel coordinate along the y-axis (row) for the given zone.
maxX	The maximum observed pixel coordinate along the x-axis (column) for the given zone.
maxY	The minimum observed pixel coordinate along the y-axis (row) for the given zone.

Important: All pixel values are internally cast to double before being summarised. Information loss may occur, if the precision and/or scale of the ValueImage (or ZoneImage) data type is larger than that of double.