Re: IR images index scale not linear and disjunct help?!

Posted by Gabriel Landini on Nov 28, 2009; 10:26am
URL: http://imagej.273.s1.nabble.com/IR-images-index-scale-not-linear-and-disjunct-help-tp3690302p3690304.html

On Saturday 28 November 2009, you wrote:
> to analyze the images using imagej.  Yet I am having trouble with the
> relationship between the index value and the temperature scale.  When I
>  make a profile plot of the scale bar the plot  is almost linear except at
>  very high temperatures when the index values drop to low values again
> (attached?).

Without seeing the image it is difficult to know what is going on, but I guess
that the intensity (a greyscale value generated by the profile plot) of a
colour (3 values) scale bar is not the right way to recreate the calibration.

You might have to create a new image where each rbg triplet value in the scale
bar corresponds to the index value of that triplet in the LUT.
Only then you could apply a calibration if you know what the indexes
correspond to.

G.