Unexpected behaviour of profile length

[Pierre1981]

Hello,

I am using the profile function and I have quite some issues when the spline I use has a 150 > length > 50 pixels and a width > 1 pixel.

Using the menu or a macro command such as:

profile = getProfile();
print(profile.length);

gives 100 pixels in length when the selection is actually quite different.
I tried many times and always got the same answer.

I have the latest version of ImageJ. This seems to be a problem which is perturbing for my application and it could be important for others...

Kind regards,
Pierre

[Rasband, Wayne (NIH/NIMH) [E]]

On Jan 24, 2013, at 3:39 PM, Pierre1981 wrote:

> Hello,
>
> I am using the profile function and I have quite some issues when the spline
> I use has a 150 > length > 50 pixels and a width > 1 pixel.
>
> Using the menu or a macro command such as:
>
> profile = getProfile();
> print(profile.length);
>
> gives 100 pixels in length when the selection is actually quite different.
> I tried many times and always got the same answer.
>
> I have the latest version of ImageJ. This seems to be a problem which is
> perturbing for my application and it could be important for others...

Use the Edit>Selection>Interpolate command and set the interval to 1 to insure that the points that define the line are spaced one pixel apart.

  run("Interpolate", "interval=1 smooth");
  profile = getProfile();
  print(profile.length);

-wayne

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