Re: Lookup tables and subsequent measurements

Posted by Manuel Jose Muñoz Martinez on Apr 23, 2008; 8:27pm
URL: http://imagej.273.s1.nabble.com/Lookup-tables-and-subsequent-measurements-tp3696434p3696441.html

Goog aftrnoon Christopher
I'm working on a similar project, I apply a spectrum LUT over grayscale
ultrasound images. I obtain values analizyng the histogram of a ROI, pehaps
this is what yu´re looking for.

2008/4/23 Christopher Lloyd <[hidden email]>:

> Good afternoon,
>
> In the course of my research I need to change the greyscale values of
> 8-bit grey images that come
> from an ultrasound machine to a new lookup table.  I've made the custom
> lookup table, and when I
> apply this table to an image using Image -> Color -> Edit LUT... -> Open
> (and selecting the saved
> LUT) you can immediately see that the displayed image changes to conform
> to the new greyscale
> LUT.  However, the research involves looking at the mean greyscale value
> of a region of interest in
> the image; application of the custom lookup table has no effect on the
> measurement values that
> come out of ImageJ, either for the Analyze -> Measure route or for a line
> profile that is drawn in the
> image.
>
> So, my question is: can a lookup table be applied to an image that
> actually has some effect on the
> measurements done on the image, or is the LUT a superficial way of viewing
> the images without
> altering the underlying data whatsoever?  I couldn't find any matching
> inquiries in the archive, except
> for one suggestion about going from grey to RGB and back (which didn't
> work, sadly).
>