Particle filter in Vision Assistant only sometimes works

[jman1]

I'm trying to process some images using something very similar to the "cell analysis" script provided in Vision Assistant.  I modified the Particle Filter operation to keep particles with areas between 100 and 200 pixels.  I'm testing the script on a sequence of 10 sample images.  For 7 of the images, everything works fine (2 particles remain, with areas 100-200 pixels).  But for 3 of the images, a third particle also remains with an area ~30 pixels.  How can this particle make it through the filter, and for only some of the images?  A much larger particle (~500 pixels) is always removed successfully.

Thanks.

[muks]

Mostlikely you would have added some other parameters like holes area or something and the particle will be removed only if that condition is also satisfied. Just a guess. Can you post a screenshot of what all the parameters you have set in vision assistant?

[muks]

Also post the image.

[jman1]

You're exactly right.  There was an Area condition also set.  I wasn't aware of it becuase I just copied the Particle Filter operation from the sample Cells script and put in a Threshold condition, but it retained the old Area condition from the original Cells filter.  It's good to know that when multiple conditions are set, the filter is an AND, not an OR, so all conditions must be met for particles to be kept/removed.

Thanks.

[muks]

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jman1 wrote:

You're exactly right.  There was an Area condition also set.  I wasn't aware of it becuase I just copied the Particle Filter operation from the sample Cells script and put in a Threshold condition, but it retained the old Area condition from the original Cells filter.  It's good to know that when multiple conditions are set, the filter is an AND, not an OR, so all conditions must be met for particles to be kept/removed.

Thanks.

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Yup and Adding more parameters make the elimination very much particle specific.