Measure the droplet diameter

[TruySaigon]

Dear KNIME developers and Users,

I am doing a project that is required to measure the droplet diameter. I am trying to measure the diameter by analyzing the image. Can some one could give me a hint to cope with this problem? what could be the workflow for this task? I include my sample picture below.
Hope to have some support from the community.
thank you very much!
IMG-0715|690x318

[TruySaigon]

@gab1one could you help me with this task? please

[Martyna]

Hi,

maybe this topic is related to yours and could somehow inspire you how to start:

Individual tracking

Hey everyone, I was wondering if it is possible in KNIME to track objects separately, but in such a way that one can clearly identify which values belong to which objects. An example: [T8B2_0856][T8B2_0861][T8B2_0866] I’d like to track the centroids of the objects separately(and other geometric characteristics like diameter, etc), but in the end I have to know which value belongs to which object. Furthermore, you see that two of the three objects are connected to each other. i have herad of…

Best,
Martyna

[TruySaigon]

Hi @Martyna,
I am very glad for your response
I’ve tried to start with simple work to detect the droplet but when I crop the image to apply the Global thresholder but it turned out not working.

what could I do to improve the detecting algorithm?
thank you

[TruySaigon]

and the data from the the interactive table. How can we convert it from pixel to mm? is there any node or method to convert the unit in Knime?
I measure and got some result but I could not convert it back to mm
thank you

[gab1one]

Hi @TruySaigon,
I would start by subtracting the average over all your images from each image. If you look into the linked post there should be a bit on it, if you upload a few more example pictures, I can take a look myself.

best,
Gabriel

[TruySaigon]

Thank you for your reply!! @gab1one

These are some sample pictures that I would analyze.

I just need to calculate the diameter of these falling droplets.
I would be very grateful if you could help me with this problem, please

Thank you very much

[TruySaigon]

Hi @gab1one,
I had attached some sample pictures
I hope that you could have a look at them.

thank you very much
best regards

[gab1one]

High @TruySaigon,
the images that you uploaded are very small, I can’t really do much with them. I thought you would upload a few more like the one from your first post.

best,
Gabriel

[TruySaigon]

Hi @gab1one,
these are the original pictures of them.
I thought I might change them to a green background for better detection.

I hope that you could have a look at them, please!!!
thank you very much
best regards,
Duy

[TruySaigon]

Hi @gab1one,
I have re-upload the raw pictures of falling droplets above.
I hope that you could have a look at them, please.
thank you very much
I am looking forward to hearing from you

[TruySaigon]

Hi @gab1one,
After reading through some reference,
I have come up with the workflow in the attached file.
but when I tried out with different flow rates, the results are not consistent.
in the Quantile Filter node, I always have to vary the value of quantile and span numbers.
To be honest, I haven’t known how to correct those values.
I hope you could have a look at the workflow and suggest some ideas that I could improve it.

Thank you very much
I am looking forward to hearing from you
Best regards,

Duy
Droplet Area.knwf (463.3 KB)