Minimum Filter
The Minimum filter enhances dark values in the image by
increasing its area. Similar to a dilate function each 3x3 (or other window
size) is processed for the darkest surrounding pixel. That darkest pixel then
becomes the new pixel value at the center of the window.
For example, given the grayscale 3x3 pixel neighborhood;
|
22
|
77
|
48
|
|
150
|
77
|
158
|
|
0
|
77
|
219
|
The center pixel would be changed from 77 to 0 as it is the
darkest pixel within the current window.
Try this filter on images containing peoples faces. It can
be used as a simple eye detector.
Interface
Instructions
1. Direction - Select which axis you want the min filter to operate on
2. Size - Select the window size of the min filter
Example
| Source | Min Filter |
 |  |
See Also
Max
Midpoint Filter
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