Introduction

Errors in Image Intensity

Errors in Line Estimation

Errors in Movement

Erroneous Shape Estimation

Errors in Image Intensity
Waves Pattern

Figure 1

This pattern is a black and white checkerboard with small squares placed in the corners of the black tiles near the edges. This creates the illusion of a wave in it.

The white squares change the type of edge that separates the tiles of the checkerboard. They create bars - there is a white area (from a little white square) next to a black bar (from a black checkerboard tile) next to a white area (from a white checkerboard tile). The edges at the boundaries of the bar (type 2 edges) drift apart under smoothing while the other edges between the black and white tiles (type 1 edges) stay in place.

The following picture is a closer look at the edge detection on the smoothed image of the Wave pattern.

Figure 2

The next set of pictures takes an even closer look and provides movement vectors that show how the edges move from their original positions.

The video below illustrates the computations.