What is the LUT meaning?

[panovr]

Hi,
  I find that ImageJ has some commands like "Image -> Color -> Show LUT"
use LUTs, and it also has a subfolder named "Luts".
  What is the meaning of LUT? How to use LUT?
  Thanks!

Yili

[Joel Sheffield]

LUT is the abbreviation for look-up-table.  Simply, a LUT is a table
of equivalents that convert brightness and darkness in an image into
numbers.  Thus in an 8-bit gray scale system, black is set to zero,
and white is 255, and all of the other gradations of intensity are
given values between them.  These days, a LUT actually consists of
three values for each intensity, one for red, green and blue.  This
is an economical way to introduce color into an image.

You can look at an 8-bit sample image in ImageJ and experiment with
the different luts that are present to see how they work.

You need to look at a basic image processing text for a full
discussion.  However, you might get some basic information from
http://micro.magnet.fsu.edu


Search for "LUT"

Date sent:       Tue, 2 May 2006 22:21:33 -0400
Send reply to:   ImageJ Interest Group <[hidden email]>
From:           Yili Zhao <[hidden email]>
Subject:         What is the LUT meaning?
To:             [hidden email]

> Hi,
>   I find that ImageJ has some commands like "Image -> Color -> Show
>   LUT"
> use LUTs, and it also has a subfolder named "Luts".
>   What is the meaning of LUT? How to use LUT?
>   Thanks!
>
> Yili

Joel B. Sheffield, Ph.D
Department of Biology
Temple University
Philadelphia, PA 19122
Voice: 215 204 8839
e-mail: [hidden email]