Posted by
Gabriel Landini on
Aug 08, 2010; 9:29am
URL: http://imagej.273.s1.nabble.com/SCALE-tp3687327p3687331.html
On Sunday 08 August 2010, you wrote:
> I am new to the ImageJ software and I
have a question, I am working with
> dough and analyzing air bubbles of the
dough with a light microscope. The
> light microscope does not have a scale
and I was wondering how do I get a
> so that I can start accumulating the
results. I will be measuring the
> area, length, and width.
This is called
spatial calibration.
You can photograph a stage micrometer a the
magnification you are using and so you know how many pixels fit in a known
distance. From this you know what is the dimension of one pixel (actually,
the inter-pixel dimension because pixels should be considered points).
Then
you enter this value as a spatial calibration in the Image Properties. Then
the results of the measurements can be given in calibrated units. If you
save the images as tiff, the calibration will be saved in them.
This is the
first thing one should do in a new microscope or a new camera (assuming that
it is a fixed camera, without zoom) for all the objectives. You should keep
the values as they can be re-used later on and/or add them to a plugin like
this one, which makes things easier if you deal with several combinations of
microscopes and
cameras.
http://rsb.info.nih.gov/ij/plugins/microscope-scale.htmlCheers
G.