MaxPool¶

Versioned name: MaxPool-1

Category: Pooling

Short description: Reference

Detailed description: Reference

Attributes:

• strides

• Description: strides is a distance (in pixels) to slide the window on the feature map over the (z, y, x) axes for 3D poolings and (y, x) axes for 2D poolings. For example, strides equal “4,2,1” means sliding the window 4 pixel at a time over depth dimension, 2 over height dimension and 1 over width dimension.

• Range of values: integer values starting from 0

• Type: int[]

• Default value: None

• Required: yes

• Description: pads_begin is a number of pixels to add to the beginning along each axis. For example, pads_begin equal “1,2” means adding 1 pixel to the top of the input and 2 to the left of the input.

• Range of values: integer values starting from 0

• Type: int[]

• Default value: None

• Required: yes

• Note: the attribute is ignored when auto_pad attribute is specified.

• Description: pads_end is a number of pixels to add to the ending along each axis. For example, pads_end equal “1,2” means adding 1 pixel to the bottom of the input and 2 to the right of the input.

• Range of values: integer values starting from 0

• Type: int[]

• Default value: None

• Required: yes

• Note: the attribute is ignored when auto_pad attribute is specified.

• kernel

• Description: kernel is a size of each filter. For example, kernel equal (2, 3) means that each filter has height equal to 2 and width equal to 3.

• Range of values: integer values starting from 1

• Type: int[]

• Default value: None

• Required: yes

• rounding_type

• Description: rounding_type is a type of rounding to be applied.

• Range of values:

• ceil

• floor

• Type: string

• Default value: floor

• Required: no

• None (not specified): use explicit padding values.

• same_upper (same_lower) the input is padded to match the output size. In case of odd padding value an extra padding is added at the end (at the beginning).

• valid - do not use padding.

• Type: string

• Default value: None

• Required: no

• dilations

• Description: dilations denotes the distance in width and height between elements in the filter. For example, dilation equal 1,1 means that all the elements in the filter are neighbors, so it is the same as for the usual pooling. dilation equal 2,2 means that all the elements in the filter are matched not to adjacent elements in the input matrix, but to those that are adjacent with distance 1.

• Range of values: integer value starting from 0

• Type: int[]

• Default value: list of 1(no dilation)

• Required: no

• data_format

• Description: data_format denotes the data format of the input and output data.

• Range of values: NXC or NCX (X means HW for 2D, DHW for 3D)

• Type: string

• Default value: NXC

• Required: no

Inputs:

• 1: input - the input tensor. Required.

Outputs

• 1: output - the result tensor.

Mathematical Formulation

$output_{j} = MAX\{ x_{0}, ... x_{i}\}$