control size of iterations to a fine scale

[vanessajune77]

Hello Image J Listserv,

I would like to control the size of iterations to 1, 2 or 3 microns. I am aware that you can go to binary settings and adjust the iterations, but it is not possible to adjust lower than 1. Images were taken with (1024x1024).

If 1 pixel is 265 microns, does that mean that I am only able to dilate a minimum of 265 microns per diation?

That seems such a large increase considering my bacterium are 5 microns. Would the images have to be taken with better resolution (possibly 2048x2048)  in order to increase my ROi's by a much finer scale  (i.e. 3 microns)?

Final question is that is there a way to increase the ROI that is smaller than the pixel in the image or is that just a limitation of the image that I have taken?

Thank you for the effort and time you put into answering this question.

Vanessa O'Donnell

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[Herbie-3]

Vanessa,

as far as I understand, your images are simply not well-resolved.

If it is true that the _distance_ between image data points, i.e. the
sampling distance, is really 265 microns, then you wont be able to see
the desired structures if they measure only about 5 microns. At best
your bacterium could be represented by a single data point.

Please understand that what you get from a digital camera is an array of
data points, i.e. numbers. There is nothing in between this points.

The display on your computer screen of such an array is somewhat
misleading, as it represents each data point as a small rectangular area
(most often a square) of a constant gray value that represents the
number. In other words, every point is represented by an area (it is
smeared out) to make the point visible, because points have no extension
and as such wouldn't be visible.

In order to resolve your objects you will need a _much_ higher
magnification of your microscope. In case you are well below the optical
resolution limit (diffraction limit) of your microscope, a higher
resolving camera may help as well. But I doubt that this holds true.

In any case, you should first test whether the present sampling
distance, is really 265 microns...

Good luck

Herbie

:::::::::::::::::::::::::::::::::::::::::::
On 06.05.14 16:48, Vanessa O'Donnell wrote:

> Hello Image J Listserv,
>
> I would like to control the size of iterations to 1, 2 or 3 microns.
> I am aware that you can go to binary settings and adjust the
> iterations, but it is not possible to adjust lower than 1. Images
> were taken with (1024x1024).
>
> If 1 pixel is 265 microns, does that mean that I am only able to
> dilate a minimum of 265 microns per diation?
>
> That seems such a large increase considering my bacterium are 5
> microns. Would the images have to be taken with better resolution
> (possibly 2048x2048)  in order to increase my ROi's by a much finer
> scale  (i.e. 3 microns)?
>
> Final question is that is there a way to increase the ROI that is
> smaller than the pixel in the image or is that just a limitation of
> the image that I have taken?
>
> Thank you for the effort and time you put into answering this
> question.
>
> Vanessa O'Donnell
>
> -- ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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ImageJ mailing list: http://imagej.nih.gov/ij/list.html