Extreme range filter

The extreme span filter is a non-linear edge detector used in image processing and is used for computer-aided processing of two-dimensional image files. An attempt is made to delimit two-dimensional areas from one another in an image. Edge detectors recognize the boundaries between the different surfaces and mark them. This creates a new picture.

An analytical description is possible as follows:

${\displaystyle h_{nm}=max_{i,j}\{f_{n+i,m+j}\}\ -\ min_{i,j}\{f_{n+i,m+j}\}}$

If a rectangular window is used, the 2D minimum and 2D maximum can be separated. With noisy images, this filter is only useful with pre-smoothing.

More edge detectors

• Prewitt operator
• Sobel operator

Individual evidence

1. ↑ keola: threshold operations. September 14, 2014, accessed June 11, 2019 . 
2. ↑ Prof. EG Schukat-Talamazzini: INTELLIGENT SYSTEMS. March 19, 2019, accessed June 11, 2019 .