Image Interpolation

Bilinear Interpolation

Heard Jack Zhang from NVIDIA say this term while he was working on ESS.


notes from Cyrill Stachniss.

Bilinear Interpolation

This is intuitive. To calculate the new intensity value, compute a weighted average of the 4 neighbouring pixel intensity values.

\begin{align} b(x,y) = &a_{00} (1- \Delta x)(1- \Delta y) + a_{01}(1-\Delta x)\Delta y \\ &+ a_{10} \Delta x (1 - \Delta y) + a_{11} \Delta x \Delta y \end{align}

  • Where are the 4 neighbouring pixel intensity values


Notice that things seem to be normalized between 0 and 1 here. I don’t know how I am supposed to do this in practice.

Cyrill Stachniss likes to write this more compact form

However, be careful since doesn’t correspond to .

How am I supposed to determine c_{ij}?

You need to compare the original equation term by term.

c_{01} &= a_{01} - a_{00} \\ c_{10} &= a_{10} - a_{00} \\ c_{11} &= a_{11} - a_{10} - a_{01} + a_{00} \\ \end{align}$$ ![[attachments/Screenshot 2023-10-08 at 1.38.46 PM.png]]