## What's the sum in the structure tensor

Moderator: Computer Vision

Flix
Erstie
Beiträge: 20
Registriert: 14. Jan 2013 12:37

### What's the sum in the structure tensor

Hi again,

in the slides (l9 p. 44, l5 p. 68) the structure tensor is denoted as

$$H = \sum\limits_{x,y \in R} \begin{pmatrix} I_x(x,y)^2 & I_x(x,y) I_y(x,y) \\ I_x(x,y) I_y(x,y) & I_y(x,y)^2\end{pmatrix}$$

In praxis I always calculated the structure tensor for a single pixel $$(x,y)$$ without summarizing anything. So what does the sum mean?

lustiz
Mausschubser
Beiträge: 70
Registriert: 29. Apr 2009 10:28

### Re: What's the sum in the structure tensor

Flix hat geschrieben:Hi again,

in the slides (l9 p. 44, l5 p. 68) the structure tensor is denoted as

$$H = \sum\limits_{x,y \in R} \begin{pmatrix} I_x(x,y)^2 & I_x(x,y) I_y(x,y) \\ I_x(x,y) I_y(x,y) & I_y(x,y)^2\end{pmatrix}$$

In praxis I always calculated the structure tensor for a single pixel $$(x,y)$$ without summarizing anything. So what does the sum mean?
This is for LK-Flow. We assume a constant optical flow over the whole window (s.t. we assume spatial smooth flow). You do sum up over all pixels of the window/region.

Flix
Erstie
Beiträge: 20
Registriert: 14. Jan 2013 12:37

Thanks