9.3. Distance Map

9.3.1. Yleiskatsaus

Each pixel in the image is replaced with a gray value dependent on the distance to the nearest obstacle pixel, generally a boundary pixel. Different methods can be used to calculate the distance.

9.3.2. Suotimen käynnistäminen

This filter is found in the image window menu under FiltersGenericDistance Map….

9.3.3. Asetukset

Kuva 17.173. Distance Map options

”Distance Map” options

Presets, Preview, Split view
[Huomaa] Huomaa

These options are described in Kohta 2, ”Common Features”.


Metric is a topology term. Three methods are available:

  • Euclidean default: the distance is a line.

  • Manhattan: the distance is the sum of the one-dimensional distances along the X and Y axes.

  • Chebyshev: the distance is the maximum of the one-dimensional distances along the X and Y axes.

Threshold low

Default is 0. Increasing this value selects higher lightness pixels

Original image for examples. Threshold low will be progressively increased. Lightness: dark red = 0.070; bright red = 0.223; green = 0.133

Kuva 17.174. Threshold low example

”Threshold low” example

Threshold low = 0: only border distances are visible.

”Threshold low” example

Threshold low = 0.070: dark red circle appears.

”Threshold low” example

Threshold low = 0.133: green circle appears.

”Threshold low” example

Threshold low = 0.223: bright red circle appears.

Threshold high

Default is 1. Decreasing this value makes result darker.

Grayscale Averaging

Number of computations for grayscale averaging.


This option is checked by default. If you uncheck it, no blur is created.

Kuva 17.175. Normalize example

”Normalize” example

Normalize option checked.

”Normalize” example

Normalize option unchecked.


The result of this filter can be larger than the original image. With the default Adjust option, the layer will be automatically resized as necessary when the filter is applied. With the Clip option the result will be clipped to the layer boundary.

9.3.4. Using Distance Map filter

Searching for an example using Distance map filter in image processing...