Arithmetic function

Overview

The Arithmetic function performs an arithmetic operation between two rasters, or a raster and a scalar operation, and vice versa.

Notes

The following table illustrates the Extent options:

Input rasters	Extent if First	Extent if Last	Extent if Intersection	Extent if Union

The Operation options are as follows:

• Plus—Outputs the sum of all the corresponding pixel values for each raster.

  output = Raster1 + Raster2

  

• Minus—Outputs the difference between the corresponding pixel values for each raster. This can be used to calculate change detection.

  output = Raster1 - Raster2

  

• Multiply—Outputs the product of the corresponding pixel values for each raster. This can be used to perform some cost functions.

  output = Raster1 × Raster2

  

• Divide—Outputs the divisible result between the corresponding pixel values for each raster.

  output = Raster1 ÷ Raster2

• Power—Outputs the product of the corresponding pixel values raised to the power of the input raster or scalar.

  output = Raster1Raster2

• Mode—Outputs the pixel value of all overlapping pixels that occurs the most. For example, if there are six bands in a raster, there will be six overlapping pixels. For the values 4, 5, 6, 4, 7, 9, the mode value is 4.

Parameters

Parameter	Description
Raster	The first input raster dataset.
Raster2	The second input raster dataset.
Operation	The arithmetic operation to be performed between the two input rasters. The options are as follows: Plus—Outputs the sum of all the corresponding pixel values for each raster. Minus—Outputs the difference between the corresponding pixel values for each raster. This can be used to calculate change detection. Multiply—Outputs the product of the corresponding pixel values for each raster. This can be used to perform some cost functions. Divide—Outputs the divisible result between the corresponding pixel values for each raster. Power—Outputs the product of the corresponding pixel values raised to the power of the input raster or scalar. Mode—Outputs the pixel value of all overlapping pixels that occurs the most. For example, if there are six bands in a raster, there will be six overlapping pixels. For the values 4, 5, 6, 4, 7, 9, the mode value is 4
Cellsize Type	Cellsize Type defines how to compute the pixel cell size of the output when the input rasters have different pixel cell sizes. First Of—Defines the output pixel cell size using the cell size of the first input raster. Min Of—Defines the output pixel cell size using the minimum cell size of the input rasters. Max Of—Defines the output pixel cell size using the maximum cell size of the input rasters. This is the default. Mean Of—Defines the output pixel cell size using the mean (average) of both input rasters. Last Of—Defines the output pixel cell size using the cell size of the last input raster.
Extent Type	Extent Type defines how to compute the extent of the output when the input rasters have different extents. First Of—Defines the output extent using the extent of the first input raster. Intersection Of—Defines the output extent as the intersecting area of the input rasters. This is the default. Union Of—Defines the output extent as the total extent of the input rasters. Last Of—Defines the output extent using the extent of the last input raster.