Population Threshold
The Population Threshold module will threshold and image based on the number of pixels within the
specified window. Similar to the 'game of life' each pixel's neighborhood is scanned to determine
if the non-black pixel lives in a neighborhood whose population is greater than some specified
threshold. If it does then the pixel is set to white, otherwise it is set to black.
This procedure will join areas of high population and eradicate areas of lower population to
create an image that is more global in features with much less detail. The algorithm is
useful when an image contains many small blobs that need to be connected to form larger areas
that better represent the overall structure of the image.
This module is useful in reducing image noise by producing a threshold that is sensitive
to population boundaries.
Interface
Instructions
1. Population Threshold - Select the threshold used to test if a pixel lives in a populated
neighborhood. Lowering the threshold will set more pixels white, increasing the threshold will
cause more pixels to disappear.
2. Intensity Threshold - Select the threshold used to determine if a pixel is to be considered
on or off. You can use other thresholding (like auto-threshold) to create a binary image that
is them used by the population threshold.
3. Window Size - select the size of the neighborhood that will be scanned for 'on' pixels. Note that
the larger the window size the more connected the resulting blob will become but the more
inexact edge boundaries will become.
Example
| Source |
 |
| RGBFiltered to produce a noisy image |
 |
| Result of Population Threshold |
 |
Variables
See Also
Blob Size
Blob Filter
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