Brain Imaging & Analysis Center

usage: -expr censor [timeref] [flag [filloption]]

CENSOR replaces flagged with new values, or it can completely remove images. Which images to censor is controlled by a reference time series. By default, the reference time series is the data set's “ACTIVE” reference timeline (0/1 value for each image). Alternatively, a reference time series can be specified explicitly by name as the first argument (TIMEREF).

Usually the reference series should have at least as many values as their are images, in which case the images to be censored are those for which the corresponding reference value is less than or equal to zero (any positive reference value means keep that image).

Alternatively, if the FLAG argument includes the 8 option, then the reference series is assumed to be an explicit list of which image numbers to censor. Image numbering always starts with 0 for the first image of the first volume, then the 2nd image of the first volume, etc. For example, if a data set has 20 image slices per volume and TIMEREF has values [ 0, 4, 107 ] then the only images to be censored would be: slice 0 volume 0, slice 4 volume 0, and slice 7 volume 4. Such a TIMEREF must contain only unique values sorted in ascending order; the list can be any length up to the total number of images.

What happens to censored images depends on the values of the FLAG and FILLOPTION arguments. FILLOPTION can be a number, indicating which image volume of the data being censored to use as fill images, or it can be the name of a 3D image data set (with the same XYZ dimensions as the data being censored).

FLAG - censoring operation:
* 0 - replace with linear interpolation (unless FILLOPTION specified)
* 1 - replace with spline interpolation
* 2 - replace with zeros (blank image)
* 3 - remove image entirely making shorter image series (blank images added at end)
* 4 - match post-mean to pre-mean
* 8 - reference is list of image numbers to remove; otherwise is 0/1 flag
* 16 - replace with value at 1st censored time point at or after timept FILLOPTION
* 17 - replace with value at 1st uncensored time point at or after FILLOPTION
* 18 - replace with value at time point FILLOPTION
* 32 - replace with FILLOPTION data set images

Default FLAG is:
* 0 if FILLOPTION is 0 or not specified, or
* 16 if FILLOPTION is a number, or
* 32 if FILLOPTION is data set name

See Also:
fScan Home, fScan Manual, CmdLineOptions, Expression Command, Manual Help