Function Description

Operator Function

Performs resampling operations on the input tensor. This operator uses two interpolation algorithms: Nearest Neighbor and Linear.

Formula

• The nearest neighbor interpolation algorithm is dst(n,c,oh,ow) = src(n,c,ih,iw), where:
  • ih = [(oh + 0.5)/F_h − 0.5]; and
  • iw = [(ow + 0.5)/F_w − 0.5].
• The mathematical formula for bilinear sampling is dst(n,c,oh,ow) = src(n,c,ih₀,iw₀) × (1 − W_ih) × (1 − W_iw) + src(n,c,ih₁,iw₀) × W_ih × (1 − W_iw) + src(n,c,ih₀,iw₁) × (1 − W_ih) × W_iw + src(n,c,ih₁,iw₁) × W_ih × W_iw, where:
  • ih₀ = ⌊oh + 0.5F_h − 0.5⌋;
  • ih₁ = ⌈oh + 0.5F_h − 0.5⌉;
  • iw₀ = ⌊ow + 0.5Fw − 0.5⌋;
  • iw₁ = ⌈ow + 0.5Fw − 0.5⌉;
  • W_ih = oh + 0.5F_h − 0.5 − ih₀; and
  • W_iw = ow + 0.5F_w − 0.5 − iw₀.

  Table 1 Formula parameters

  Parameter	Description
  src	Input source tensor.
  dst	Target tensor.
  n	Dimension 1 to be sampled.
  c	Dimension 2 to be sampled.
  ih	Input height.
  iw	Input width.
  oh	Output height.
  ow	Output width.