http://imagej.273.s1.nabble.com/curvature-along-the-outline-of-a-thresholded-object-tp5023589p5023635.html
and I'm not perfectly sure about its cause. Presently, I conjecture that
implement it. However, the first step will be to ensure that the
> Dear Herbie,
>
> enclosed are two plots one with Thomas' the other one with your code. The
> circles are the data. The line is a spline. With one little exception both
> codes find the same number of locations with negative curvatures. Your code
> produces much smoother data but does not run smoothly across the junction
> between begin and end of the data file. Please note that this junction is
> in the middle of the plot.
>
> Best, Thomas
>
> Am Mo., 6. Juli 2020 um 18:30 Uhr schrieb Herbie <
[hidden email]>:
>
>> Dear Bob and all others interested in this topic,
>>
>> meanwhile I've coded a little macro that appears working reasonably well.
>>
>> As expected, the interpolation is crucial and it turns out that a
>> reasonable
>> angle increment, i.e. number of local curvature values, for the sample
>> images (450x450) provided by Thomas Fischer is about one degree or better
>> less.
>>
>> My present interpolation strategy for the sample images is:
>>
>> //
>> run( "Create Selection" );
>> run( "Interpolate", "interval=4 smooth" );
>> run( "Fit Spline" );
>> run( "Interpolate", "interval=2 adjust" );
>> //
>>
>> Finally I decided not to use polar coordinates but parametrized
>> coordinates:
>> <
>>
https://en.wikipedia.org/wiki/Curvature#In_terms_of_a_general_parametrization>>>
>>
>> For the sample image "0453.tif" I get 390 values.
>> Attached please find the results table as a text file.
>> Results_0453.txt
>> <
http://imagej.1557.x6.nabble.com/file/t380516/Results_0453.txt>
>>
>> For comparison, I really should like to see the corresponding results of
>> your approach.
>>
>> Regards
>>
>> Herbie
>> :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
>>
>> Robert Dougherty wrote
>>> Herbie,I have a post hoc processing step in my code. I smooth the
>>> reciprocal of the radius of curvature. I actually use a weighted power
>>> mean for that, as it seemed like the right thing to do, without much
>>> evidence.Bob
>>>
>>>
>>> Thomas,Thanks for the feedback and context. There are several things I
>>> want to do with this, but I need to focus on my day job for a while.Bob
>>>
>>>
>>> Sent from Smallbiz Yahoo Mail for iPhone
>>>
>>>
>>> On Sunday, July 5, 2020, 10:14 AM, Thomas Fischer <
>>
>>> thmfischer@
>>
>>> > wrote:
>>>
>>> Dear Bob,
>>>
>>> My reply is late because I had computer problems. The result of the
>> plugin
>>> looks nice. In order to use it I would need two features
>>> 1) A parameter to tune the sensitivity. Right now it is not sensitive
>>> enough for my purpose. I am aware that an increase in sensitivity would
>>> make the result more noisy. But as with the plugin of Thomas I would do
>>> the
>>> smoothing afterwards.
>>> 2) A list of the curvature values along the circumference. Just looking
>> at
>>> the nice result is not enough in my case. I have to extract numbers from
>>> this list.
>>>
>>> I am content with the plugin of Thomas. But as we say in German: the
>>> better
>>> is the enemy of the good.
>>>
>>> Best regards, Thomas
>>>
>>>
>>>
>>>
>>>
>>> Am So., 5. Juli 2020 um 07:33 Uhr schrieb Robert Dougherty <
>>
>>> rpd@
>>
>>> >:
>>>
>>>> Gabriel,
>>>> Thanks. In case it matters, there is a new version with smoother
>>>> calculation and a black background.
>>>> Bob
>>>>
>>>> On Saturday, July 4, 2020, 11:33:56 AM PDT, Gabriel Landini <
>>>>
>>
>>> g.landini@.ac
>>
>>>> wrote:
>>>>
>>>> Thanks Bob, I can confirm that it works fine.
>>>> I think colourblind observers (red-green type) would see the green as
>>>> some
>>>> shades of yellow and blue as blue. At lease that is what the Dichromacy
>>>> plugin
>>>> shows.
>>>> Regards
>>>>
>>>> Gabriel
>>>>
>>>>
>>>> On Saturday, 4 July 2020 18:05:09 BST you wrote:
>>>>> Gabriel,
>>>>> In the meantime, I tried and failed to track down how ImageJ is
>>>> supposed
>>>> to
>>>>> load the Phase LUT. Giving up, I changed the code to use another
>>>>> sign-friendly LUT that I coded explicitly. Now Curvature displays the
>>>>> results in green-blue. Going forward, it may be a question of which
>>>> color
>>>>> scheme is better. One could experiment by running the new version of
>>>>> Curvature and then manually changing the LUT to Phase to simulate the
>>>> old
>>>>> version. Perhaps green-blue is better for colorblindness than the
>>>> red-blue
>>>>> scheme of Phase?
>>>>>
>>>>> Bob
>>>>
>>>> --
>>>> ImageJ mailing list:
http://imagej.nih.gov/ij/list.html>>>>
>>>>
>>>> --
>>>> ImageJ mailing list:
http://imagej.nih.gov/ij/list.html>>>>
>>>
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http://imagej.nih.gov/ij/list.html>>>
>>>
>>>
>>>
>>> --
>>> ImageJ mailing list:
http://imagej.nih.gov/ij/list.html>>
>>
>>
>>
>>
>> --
>> Sent from:
http://imagej.1557.x6.nabble.com/>>
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