Hello,
do you want to change the ROI manually or programatically?
If you change the ROI manually (which seems to be your question), the change gets updated via the ROI property node also so you can read the new values.
If you want to change the ROI programatically, use the ROI property node, but write the new values instead of reading.
Best regards,
K
https://decibel.ni.com/content/blogs/kl3m3n

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