9.3. Distance Map

9.3.1. 概観

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. フィルターの呼び出し方

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

9.3.3. オプション

図17.172 Distance Map options

「Distance Map」 options

Presets, Preview, Split view
[注記] 注記

These options are described in 「Common Features」.


Metric is a topology term. Three methods are available:

  • Euclidean default: the distance is a line.

  • Manhattan

  • Chebyshev

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

図17.173 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 100. Decreasing this value makes result lighter.

Grayscale Averaging

Number of computations for grayscale averaging.


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

図17.174 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...