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.
|
|---|
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) | b) |
Applying the Window and Level technique with parameters Window=100 and Level=1100 yields
|
|---|