ID 588139 - The Dilate filter produces unexpected and incorrect results.

Problem summary
The Dilate filter produces unexpected and incorrect results. In some versions the filter appears to have no effect.
 
Customer reported version
Mari n/a
 
Customer reported platform
n/a
 
Steps to reproduce
 
1) Open Mari. Open an Example Project.

2) Create a Paint node with the following settings:
 

 
Ensure that the Color of the Paint node is set with the Alpha to maximum. This appears to cause a blue line around the paint (see below in the Actual Behaviour section). When the Alpha is set to zero, it seems that the Dilate filter does nothing at all.

3) With a black paint colour selected, paint anything onto the model. Bake the paint.
 
4) In the Node Graph, create a Bake Point node. In the Bake Point node, under the Filters tab, select Add Filter > Dilate. Ensure that Preview is set to On:
 

 
Expected behaviour
The dilate filter should "expand" the existing shapes outwards on a black and white image. See following link for example: https://stackoverflow.com/questions/5154282/dilate-erode-modify-kernel-option/5155170#5155170
 
Actual behaviour
In some cases a blue line appears around the outline of the shapes:
 

 
In other cases, the filter appears to do nothing at all:
 

 
Workaround
Unknown.
 
Reproduced by support
This bug has been reproduced in:
Mari 7.0v2 - Windows 11 / Rocky 9
Mari 4.8v1 - Windows 11
 
Earliest version tested
Mari 4.8v1
- This feature did not exist before this version