mx.nd.UpSampling

Description

Upsamples the given input data.

Two algorithms (sample_type) are available for upsampling:

  • Nearest Neighbor

  • Bilinear

Nearest Neighbor Upsampling

Input data is expected to be NCHW.

Example:

x = [[[[1. 1. 1.]
[1. 1. 1.]
[1. 1. 1.]]]]

UpSampling(x, scale=2, sample_type='nearest') = [[[[1. 1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1. 1.]]]]

**Bilinear Upsampling**

Uses `deconvolution` algorithm under the hood. You need provide both input data and the kernel.

Input data is expected to be NCHW.

`num_filter` is expected to be same as the number of channels.

Example:

x = [[[[1. 1. 1.]
[1. 1. 1.]
[1. 1. 1.]]]]

w = [[[[1. 1. 1. 1.]
[1. 1. 1. 1.]
[1. 1. 1. 1.]
[1. 1. 1. 1.]]]]

UpSampling(x, w, scale=2, sample_type='bilinear', num_filter=1) = [[[[1. 2. 2. 2. 2. 1.]
[2. 4. 4. 4. 4. 2.]
[2. 4. 4. 4. 4. 2.]
[2. 4. 4. 4. 4. 2.]
[2. 4. 4. 4. 4. 2.]
[1. 2. 2. 2. 2. 1.]]]]

Arguments

Argument

Description

data

NDArray-or-Symbol[].

Array of tensors to upsample. For bilinear upsampling, there should be 2 inputs - 1 data and 1 weight.

scale

int, required.

Up sampling scale

num.filter

int, optional, default=’0’.

Input filter. Only used by bilinear sample_type.Since bilinear upsampling uses deconvolution, num_filters is set to the number of channels.

sample.type

{‘bilinear’, ‘nearest’}, required.

upsampling method

multi.input.mode

{‘concat’, ‘sum’},optional, default=’concat’.

How to handle multiple input. concat means concatenate upsampled images along the channel dimension. sum means add all images together, only available for nearest neighbor upsampling.

num.args

int, required.

Number of inputs to be upsampled. For nearest neighbor upsampling, this can be 1-N; the size of output will be(scale*h_0,scale*w_0) and all other inputs will be upsampled to thesame size. For bilinear upsampling this must be 2; 1 input and 1 weight.

workspace

long (non-negative), optional, default=512.

Tmp workspace for deconvolution (MB)