Posted by
Justin McGrath on
Jun 04, 2008; 4:31pm
URL: http://imagej.273.s1.nabble.com/newbie-looking-for-a-digital-caliper-tool-tp3696047p3696049.html
Wouldn't drawing with the line tool then using measure work? It will
create a table of lengths, which is pretty user friendly.
If you wanted to get fancier and get a length that you're fairly sure
is perpendicular, you could find the angles of the parallel lines
(either by the user drawing with the line tool or through some image
processing technique), then calculate the length of the line segment
perpendicular to them. With a macro, you could have it so that the
user needs to only draw two lines. If you can find the angles with
image processing, then you could eliminate all user input. The Hough
transform is one that can find lines, but I don't think there's a
plugin for ImageJ. If all of your lines are vertical, you can do a
much simplified Hough transorm pretty easily.
A rotating calipers tool seems needlessly complicated.
Justin
On Wed, Jun 4, 2008 at 9:50 AM, Andrei <
[hidden email]> wrote:
> Hi all, I have a task of measuring the distance between dark lines on an
> image. I'm sure this has been done before, but I can't find where.
>
> What I need is a digital micrometer. A pair of lines that can be rotated,
> moved and spread to get relative measurments between to pairs of lines is
> all thats neede.
>
> Here's the scope: a reflective coating on a Fizeau-Tolansky micrometer will
> have fringes 2730Å apart, an area with no coating will show up as shifted
> fringes. I need a pair of rotatable parallel lines to measure the distance
> between the normal and shifted fringes, and calculate the relative
> dispalcement. I'm trying to make this usable by people with minimal
> computer understanding, and <100Å accuracy.
>
> My problem: minimal java understanding. Just the tools included in ImageJ
> are enough for an accurate measurment, but this needs to be very user-
> friendly, and I can't find anything that is so. Please send my way any
> links to related material, Java tutorials on creating a sort of digital
> caliper, related work, anything! It will be greatly appreciated.
>