Histogram

Histogram

Purpose

This program allows you to compute the histogram (which can be plotted withgnuplot) of an image or a volume. If ranges are not provided the histogram is plotted between the minimum and maximum value of that file, and if they are supplied then values outside these boundaries are not counted at all. A mask can be supplied so only those voxels within the mask will be counted.

Usage

$ histogram -i ...

Parameter

• __OR__ Input file
• `` Output histogram to a file, by default it is dumped to the screen
• `` Range for the first column by default, it is automatic
• -steps [N100] = Number of subdivisions for column 1
• `` Compute the histogram of those values within the mask. See Mask for a detailed description of possible masks

Examples and notes

Histogram of an image, result on screen

$ histogram -i image.xmp

Histogram of those values between 0 and 1 of a volume, results to a file

$ histogram -i volume.xmp -range 0 1 -steps 30 -o histogram.txt

Histogram within a mask

$ histogram -i image.xmp -mask circular -30

The first column in the resulting histogram is the density value, while the second is the number of voxels with that value.

--Main.AlfredoSolano - 17 Jan 2007