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PaddingLayer[{{m1,n1},{m2,n2},…}]

represents a net layer that pads an input array with mi elements at the beginning and ni elements at the end at level i of the array.

Details and Options
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Arguments  
Ports  
Options  
Padding  
Properties & Relations  
See Also
Tech Notes
Related Guides
History
Cite this Page

PaddingLayer

PaddingLayer[{{m1,n1},{m2,n2},…}]

represents a net layer that pads an input array with mi elements at the beginning and ni elements at the end at level i of the array.

Details and Options

  • PaddingLayer is typically used inside NetChain, NetGraph, etc.
  • The following optional parameter can be included:
  • Padding 0type of padding to use
  • Possible explicit settings for the Padding option include:
  • valpad with a constant value val
    "Fixed"repetitions of the elements on each boundary
    "Reflected"reflections of the array in the boundary
  • The default option is to pad with the value 0.
  • The Padding value "Fixed" indicates that the rectangles of pixels added at each corner should be copies of the pixels at the corners of the original array.
  • PaddingLayer exposes the following ports for use in NetGraph etc.:
  • "Input"an array of rank 1 or higher
    "Output"an array of rank 1 or higher
  • When it cannot be inferred from other layers in a larger net, the option "Input"{d1,…,dn} can be used to fix the input of PaddingLayer to be an array of dimensions d1×…×dn.
  • PaddingLayer[…][input] explicitly computes the output from applying the layer.
  • PaddingLayer[…][{input1,input2,…}] explicitly computes outputs for each of the inputi.
  • When given a NumericArray as input, the output will be a NumericArray.
  • Options[PaddingLayer] gives the list of default options to construct the layer. Options[PaddingLayer[…]] gives the list of default options to evaluate the layer on some data.
  • Information[PaddingLayer[…]] gives a report about the layer.
  • Information[PaddingLayer[…],prop] gives the value of the property prop of PaddingLayer[…]. Possible properties are the same as for NetGraph.

Examples

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Basic Examples  (2)

Create a PaddingLayer that pads a vector with zeros:

Wolfram Language code: PaddingLayer[{{1, 2}}]

Create a PaddingLayer that pads a vector with zeros:

Wolfram Language code: p = PaddingLayer[{{2, 0}}]

Apply the layer to a vector:

Wolfram Language code: p[{1, 2, 3}]

Scope  (3)

Arguments  (2)

Create a PaddingLayer that pads a vector with zeros:

Wolfram Language code: p = PaddingLayer[{{2, 0}}]

The layer threads across a batch of examples:

Wolfram Language code: p[{{1, 2, 3}, {5, 6, 7}}]//MatrixForm

Create a PaddingLayer that pads a matrix:

Wolfram Language code: p = PaddingLayer[{{1, 2}, {0, 1}}]

Apply the layer to a matrix:

Wolfram Language code: p[{{2, 3}, {5, 7}}]//MatrixForm

Ports  (1)

Create a PaddingLayer that pads an image encoded as a 3-dimensional array, using "Fixed" padding:

Wolfram Language code: p = PaddingLayer[{{0, 0}, {20, 20}, {20, 20}}, "Padding" -> "Fixed", "Input" -> NetEncoder["Image"], "Output" -> NetDecoder["Image"]]
Wolfram Language code: p[[image]]

Options  (3)

Padding  (3)

Use -999 as the padding value:

Wolfram Language code: p = PaddingLayer[{{1, 2}}, Padding -> -999]

Apply the layer to a vector:

Wolfram Language code: p[{0.1, -0.4}]

Use the "Fixed" padding method:

Wolfram Language code: p = PaddingLayer[{{1, 2}}, Padding -> "Fixed"]

Apply the layer to a vector:

Wolfram Language code: p[{0.1, -0.4}]

Use the "Reflected" padding method:

Wolfram Language code: p = PaddingLayer[{{1, 1}}, Padding -> "Reflected"]

Apply the layer to a vector:

Wolfram Language code: p[{0.1, 0.2, -0.4}]

Properties & Relations  (1)

PaddingLayer is equivalent to ArrayPad:

Wolfram Language code: pad = {{1, 2}}; data = {1, 2, 3};
Wolfram Language code: PaddingLayer[pad]@data ArrayPad[data, pad]

PaddingLayer also supports the "Fixed" padding type:

Wolfram Language code: PaddingLayer[pad, Padding -> "Fixed"]@data ArrayPad[data, pad, "Fixed"]
Wolfram Research (2017), PaddingLayer, Wolfram Language function, https://reference.wolfram.com/language/ref/PaddingLayer.html (updated 2017).

Text

Wolfram Research (2017), PaddingLayer, Wolfram Language function, https://reference.wolfram.com/language/ref/PaddingLayer.html (updated 2017).

CMS

Wolfram Language. 2017. "PaddingLayer." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2017. https://reference.wolfram.com/language/ref/PaddingLayer.html.

APA

Wolfram Language. (2017). PaddingLayer. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/PaddingLayer.html

BibTeX

@misc{reference.wolfram_2026_paddinglayer, author="Wolfram Research", title="{PaddingLayer}", year="2017", howpublished="\url{https://reference.wolfram.com/language/ref/PaddingLayer.html}", note=[Accessed: 13-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_paddinglayer, organization={Wolfram Research}, title={PaddingLayer}, year={2017}, url={https://reference.wolfram.com/language/ref/PaddingLayer.html}, note=[Accessed: 13-June-2026]}