Posted by
Gabriel Landini on
URL: http://imagej.273.s1.nabble.com/About-automatic-thresholding-program-implemented-in-ImageJ-tp5024552p5024555.html
On Wednesday, 31 March 2021 04:29:03 BST
[hidden email] wrote:
> Q1. How do I know the threshold automatically set based on each algorism is
> reasonable or not?
Let me add to Herbie's reply that you could set a hand crafted result (eg a
binary image) which you consider "reasonable" (a ground truth set, if it
exists or a gold standard if it does not) and compare that to the results
obtained with various auto-thresholding algorithms. There are some statistics
that let you do such comparisons like the Dice and the Jaccard indexes
(globally to the image or individually to each blob detected) or other
reliability measures (FP, FN, TP, TN, etc) .
> Q2. Among 16 automatic thresholding algorisms, how do you decide which
> algorithm to use for image analysis?
Following the suggestion above you could compare the reliability measures
described above and choose the method that returns the closest values to the
ideal (ie that matches your ground truth or gold standard best).
See for example Figs 5 to 7 in:
https://onlinelibrary.wiley.com/doi/full/10.1111/jmi.12474> Q3. In image analysis by automatic thresholding method, I sometimes
> encounter an error that the window of ImageJ shows“threshold not found
> after 10000 iterations”. Are there any specific conditions when this kind
> of error occurs? Is this some kind of bug?
Please have a look at the documentation of the autothresholding plguins here:
https://blog.bham.ac.uk/intellimic/g-landini-software/auto-threshold-and-auto-local-threshold/That explains the warning of the MinError method and what is the result
returned in such cases (i.e. the the Mean threshold which is the initial
estimate of the iterative process).
Regards
Gabriel
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