Posted by
Herbie on
Jan 21, 2018; 4:05pm
URL: http://imagej.273.s1.nabble.com/question-on-edge-detection-tp5019908p5019920.html
Dear Dave,
we are still far away from a robust and automatic solution but I know that
it is the goal!
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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.
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"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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