Re: adding real axes to pixel format, possible addition to ImageJ

Posted by Gabriel Landini on Jan 11, 2006; 9:45am
URL: http://imagej.273.s1.nabble.com/adding-real-axes-to-pixel-format-possible-addition-to-ImageJ-tp3704097p3704100.html

On Tuesday 10 January 2006 22:54, John Carlson wrote:
> What do you mean by calibrated image?  How do you do that in ImageJ?

Image>Properties and then you put the value of the pixel size in your real
units. You should have calculated beforehand what the calibration values
should be.
If you point to any pixels, you get the calibrated coordinates in the
statusbar (instead of in pixels). This will be offset to 0,0, so you will
only need to add/subtract any offset you need. The calibration is saved in
the tiff format. You could store the offsets as metadata in the tiff tags and
make a macro that reads them and converts to your chosen units in the
statusbar or to a new window.

> I would need to query the x and y coordinates for their values that were
> obtained from the file format we are using.

But the image is made of discrete units, so you will not be able to get more
resolution than the image that holds the data. The coordinates would be
transformed only.

If such modification to the calibration was to be made, then one suggestion is
to have a dialog that asks for the coordinates (in calibrated units) of the
top left image pixel (0,0) and that one of the lower bottom pixel
(getWidth()-1, getHeight()-1).
As I said, you could incorporate these calculations in your own macro or
plugin and store them as metadata.

I hope it helps.

Gabriel