How to find artifacts using Outlier

Indications:

Your image data appear to have excessive spikes or other artifacts, or you just want to know
Note: This utility is still under development - it will ultimately give you more information on movement, etc....

What to do:

Type:

> Outlier -i infile.ext

where infile.ext is the raw image file in any of our standard formats

Outlier accepts the following options:

-r	The time point number (counting from 1) to be used as an artifact free reference. This defaults to 0
-R	The maximum acceptable ratio of pixels whose intensitu changes to the difference in the number of increasing and decreasing pixel intensities. This is a crude motion detector. The default value is 2%
-S	The maximum fraction of the pixels that can increase above background noise levels. This is a spike detector. The default is 30%. Note that this operates on a per slice basis.
-A	The maximum fraction of the pixels in a slice that can change above or below background noise

Outlier will list the image numbers in which artifacts are suspected, as well as a brief description of the artifact type.

The program creates a file called, infile.ext.Outlier.proc that contains a table of numbers, suitable for graphing, that summarize the program output.

The full source for Outlier can be found [HERE]

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This page is maintained by Mark Cohen [updated 1.11.02]