Max Pooling 2D Layer
Libraries:
Deep Learning Toolbox /
Deep Learning Layers /
Pooling Layers
Description
The Max Pooling 2D Layer block performs downsampling by dividing the input
into rectangular pooling regions, then computing the maximum of each region. This block
accepts 2-D image data in the SSC
format (three dimensions corresponding to
two spatial dimensions and one channel dimension, in that order) and pools over the spatial
dimensions.
The exportNetworkToSimulink
function generates this block to represent a maxPooling2dLayer
object.
Limitations
The Layer parameter has limited support for the
'manual'
padding mode. It is recommended to use anmaxPooling2dLayer
object that has thePaddingMode
property set to'same'
.
Ports
Input
Input data to downsample. The data must have three dimensions corresponding to two spatial dimensions and one channel dimension, in that order.
Data Types: single
| double
| int8
| int16
| int32
| int64
| uint8
| uint16
| uint32
| uint64
| fixed point
Output
The result of downsampling the input data. The output data has three dimensions corresponding to two spatial dimensions and one channel dimension, in that order.
Data Types: single
| double
| int8
| int16
| int32
| int64
| uint8
| uint16
| uint32
| uint64
| fixed point
Parameters
To edit block parameters interactively, use the Property Inspector. From the Simulink® Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.
Main
Specify the name of a workspace variable that contains a
maxPooling2dLayer
object from a trained network. The Max
Pooling 2D Layer block configures itself by using the properties of the
object.
Programmatic Use
Block Parameter:
Layer |
Type: workspace variable |
Values:
maxPooling2dLayer object |
Default:
'layerObject' |
Data format for the input data. The options use the same
notation as the fmt
argument of the
dlarray
object, except layer blocks do not support the Batch
(B
) dimension and instead assume an observation number of
1
.
Programmatic Use
Block Parameter:
DataFormat |
Type: character vector |
Values:
'SSC' |
Default:
'SSC' |
Data Types
Minimum value of the output range that the software checks.
The software uses the minimum value to perform:
Parameter range checking for some blocks. For more information, see Specify Minimum and Maximum Values for Block Parameters (Simulink).
Simulation range checking. For more information, see Specify Signal Ranges (Simulink) and Enable Simulation Range Checking (Simulink).
Automatic scaling of fixed-point data types.
Optimization of the code that you generate from the model. This optimization can remove algorithmic code and affect the results of some simulation modes, such as SIL or external mode. For more information, see Optimize using the specified minimum and maximum values (Embedded Coder).
Tips
Output minimum does not saturate or clip the actual output signal. Use the Saturation (Simulink) block instead.
Programmatic Use
To set the block parameter value programmatically, use
the set_param
(Simulink) function.
Parameter: | OutMin |
Values: | '[]' (default) | scalar in quotes |
Maximum value of the output range that the software checks.
The software uses the maximum value to perform:
Parameter range checking for some blocks. For more information, see Specify Minimum and Maximum Values for Block Parameters (Simulink).
Simulation range checking. For more information, see Specify Signal Ranges (Simulink) and Enable Simulation Range Checking (Simulink).
Automatic scaling of fixed-point data types.
Optimization of the code that you generate from the model. This optimization can remove algorithmic code and affect the results of some simulation modes, such as SIL or external mode. For more information, see Optimize using the specified minimum and maximum values (Embedded Coder).
Tips
Output maximum does not saturate or clip the actual output signal. Use the Saturation (Simulink) block instead.
Programmatic Use
To set the block parameter value programmatically, use
the set_param
(Simulink) function.
Parameter: | OutMax |
Values: | '[]' (default) | scalar in quotes |
Choose the data type for the output. The type can be inherited, specified directly, or expressed as a data type object such as Simulink.NumericType
. When you select Inherit: Inherit via internal rule
,
Simulink chooses a data type to balance numerical accuracy, performance, and generated code
size, while taking into account the properties of the embedded target hardware.
Programmatic Use
To set the block parameter value programmatically, use
the set_param
(Simulink) function.
Parameter: | OutDataTypeStr |
Values: | 'Inherit: Inherit via internal
rule' (default) | 'Inherit: Inherit via back propagation' | 'Inherit: Same as first input' | <data type expression> |
Select this parameter to prevent the fixed-point tools from overriding the Output data type you specify on the block. For more information, see Use Lock Output Data Type Setting (Fixed-Point Designer).
Programmatic Use
To set the block parameter value programmatically, use
the set_param
(Simulink) function.
Parameter: | LockScale |
Values: | 'off' (default) | 'on' |
Specify the rounding mode for fixed-point operations. For more information, see Rounding Modes (Fixed-Point Designer).
Block parameters always round to the nearest representable value. To control the rounding of a block parameter, enter an expression using a MATLAB® rounding function in the mask field.
Programmatic Use
To set the block parameter value programmatically, use
the set_param
(Simulink) function.
Parameter: | RndMeth |
Values: | 'Floor' (default) | 'Ceiling' | 'Convergent' | 'Nearest' | 'Round' | 'Simplest' | 'Zero' |
Specify whether integer overflows saturate or wrap.
on
— Overflows saturate to either the minimum or maximum value that the data type can represent.off
— Overflows wrap to the appropriate value that the data type can represent.
For example, the maximum value that the signed 8-bit integer int8
can
represent is 127. Any block operation result greater than the maximum value causes
overflow of the 8-bit integer.
With this parameter selected, the block output saturates at 127. Similarly, the block output saturates at a minimum output value of –128.
With this parameter cleared, the software interprets the overflow-causing value as
int8
, which can produce an unintended result. For example, a block result of 130 (binary 1000 0010) expressed asint8
is –126.
Tips
Set this parameter to
on
when your model has a possible overflow and you want explicit saturation protection in the generated code.To optimize the efficiency of your generated code, keep the default
off
setting for this parameter. Using the default setting also helps you avoid overspecifying how the block handles out-of-range signals. For more information, see Troubleshoot Signal Range Errors (Simulink).When you select this parameter, saturation applies to every internal operation on the block, not just the output or the result.
In general, the code generation process can detect when overflow is not possible. In this case, the code generator does not produce saturation code.
Programmatic Use
To set the block parameter value programmatically, use
the set_param
(Simulink) function.
Parameter: | SaturateOnIntegerOverflow |
Values: | 'off' (default) | 'on' |
Execution
Specify the discrete interval between sample time hits or specify another type of sample time, such as continuous (0
) or inherited (-1
). For more options, see Types of Sample Time (Simulink).
By default, the block inherits its sample time based on the context of the block within the model.
Programmatic Use
To set the block parameter value
programmatically, use the set_param
(Simulink) function.
Parameter:
SampleTime |
Data Types:
char |
Values:
'-1' (default) | scalar |
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.
Version History
Introduced in R2024bStarting in R2025a, the default value for the Layer parameter is 'layerObject'
. In previous versions, the default value is 'layer'
. If you have code that programmatically creates Simulink and relies on variables with the name 'layer'
, update your code so that the variable has the name 'layerObject'
.
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