http://imagej.273.s1.nabble.com/question-on-edge-detection-tp5019908p5019928.html
since the aim is "... to measure the waveforms that result from the
frequencies. Having more lines / kymographs, you can correlate the results
Good luck. Ondrej.
> Dear Dave,
>
> we are still far away from a robust and automatic solution but I know that
> it is the goal!
>
> ------------------------------------------------------------
> -----------------------
> It would help if to read my previous reply to Kenneth:
>
> 1. It would be very helpful to now see at least a short sequence of images.
>
> 2. It appears quite essential to know whether the thickness-variations over
> time need to be measured along the imaged part of the artery (mean, stdDev,
> max, min) or only to be visualized/dislayed by contour lines.
>
> 3. If they are to be measured, it is necessary to get a reasonable idea of
> the desired accuracy.
> ------------------------------------------------------------
> -----------------------
>
> "May we inquire how you did that?"
>
> Concerning my approach, please see the related task/solution:
> <
http://forum.imagej.net/t/corrosion-thickness-measurement/8310>
> Image quality is much better in this case, hence the necessary
> pre-processing is less involved than it will be in the present situation.
>
> "There are some obvious jaggednesses that need to be smoothed out."
>
> More recent results show less jaggednesses. If perfect "smoothing" is
> possible depends on your answer to point 2.
>
> "Some manual steps involved?"
>
> I guess not, but I can only judge it after the inspection of a typical
> short
> image sequence.
>
> Please be aware that the previously posted contour image was obtained from
> your sample image and I can't guarantee that my approach works for other
> images as well. It depends on their quality and the form of the imaged
> vessels.
> (Although being in 16bit format, the provided sample image shows a rather
> low gray-value dynamic of 109 levels. Furthermore, it suffers from
> line-like
> artifacts but they appear to be inherent to the image acquisition process.
> Please comment!)
>
> Presently, I assume that the imaged part of the vessel is and over time
> stays more or less straight, as in the sample image. In general, I prefer
> to
> first orient the vessel horizontally. This is mandatory in case you need to
> measure its thickness (cf. point 2.).
>
> Regards
>
> Herbie
>
>
>
>
>
> --
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http://imagej.1557.x6.nabble.com/>
> --
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Mgr. Ondřej Šebesta