Window and Level Contrast Enhancement

[Laboratory]

An interactive contrast enhancement tool normaly available in image processing software is called Window and Level. It is a expansion of the contrast of the pixels within a given window range. Two parameters define the range: the middle point Level, and the width of the range Window. Another name for this operation is Intensity of Interest (IOI).

A graphic visualization of this process is shown below.

Window and Level Transfer Function

Example

A practical application of this tool is given below. The original image is a CT Image with pixel values ranging from 1024 to 1862. The histogram plotted ranges from 1000 to 1862.

a)Original image; b)Its histogram
a) b)

Applying the Window and Level technique with parameters Window=100 and Level=1100 yields

Window and Level contrast enhanced





Main DIP Menu
DIP Feedback Form
Copyright © 1997-1995 KRI, ISTEC, Ramiro Jordán, Roberto Lotufo. All Rights Reserved