Help finding plugin/process to analyse the area of a polygon

[eeh0133-2]

I am new to Image J and am trying to use it to look at changes in water
coverage on aerial images over time.
<http://imagej.1557.x6.nabble.com/file/t382363/Flight4_down_05_13_19.jpg>

My current idea is to manually select the wetted area using polygon
selection and record the number of pixels within the polygon then compare
the pixel values to deduce changes in water coverage.

How do I find the number of pixels of the selected polygon? Do you know of
any plug ins that would make this process easier/faster/better?





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[Cammer, Michael-2]

Perhaps this for each timepoint?

run("Set Measurements...", "area limit redirect=None decimal=0");
open("C:/Users/cammem01/Pictures/temp/Flight4_down_05_13_19.jpg");
run("HSB Stack");
setSlice(1);
run("Spectrum");  // optional
setThreshold(175,255);
run("Measure");
selectWindow("Results");  // reports number of pixels

Cheers-
Michael C.

-----Original Message-----
From: eeh0133 <[hidden email]>
Sent: Tuesday, June 18, 2019 3:49 PM
To: [hidden email]
Subject: Help finding plugin/process to analyse the area of a polygon

I am new to Image J and am trying to use it to look at changes in water coverage on aerial images over time.
<https://urldefense.proofpoint.com/v2/url?u=http-3A__imagej.1557.x6.nabble.com_file_t382363_Flight4-5Fdown-5F05-5F13-5F19.jpg&d=DwICAg&c=j5oPpO0eBH1iio48DtsedeElZfc04rx3ExJHeIIZuCs&r=E0xNnPAQpUbDiPlC50tp7rW2nBkvV7fujQf0RknE5bU&m=-8OxTTnH0YNqvZ4h_PtcW-VQe9ngrDWPTplPTtTDGOY&s=EiALda0r9xrK8d3QIoFlpTajvsFwbQSYdbRpwGQ0E2g&e= >

My current idea is to manually select the wetted area using polygon selection and record the number of pixels within the polygon then compare the pixel values to deduce changes in water coverage.

How do I find the number of pixels of the selected polygon? Do you know of any plug ins that would make this process easier/faster/better?





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