getsdofsb-methods: Estimate the noise standard deviation

Description Usage Arguments Value Methods Author(s) See Also

Description

Estimate the noise standard deviation. Uses an assumption that the standard deviation is a linear function of the expected mean for image intensities. qA0 and qA1 define quantiles of observed image intensities that define the range of values where this assumption is made.

Usage

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  ## S4 method for signature 'dtiData'
getsdofsb(object,qA0=.1,qA1=.98,nsb=NULL,level=NULL)

Arguments

object

Object of class "dtiData"

qA0

level for lower quantile of image intensities

qA1

level for upper quantile of image intensities

nsb

number of diffusion weighted image to use

level

level for mask

Value

An object of class "dtiData" with results in slot sdcoef in components 5: intercept parameter, 6: slope parameter for linear model, 7: lower bound (depending on qA0) and 8: upper bound (depending on qA1).

Methods

signature(object) = "ANY"

Returns a warning.

signature(object) = "dtiData"

Returns a dtiData object with estimated standard deviation parameters in slot sdcoef.

Author(s)

Karsten Tabelow [email protected]
J\"org Polzehl [email protected]

See Also

dtiData, dwi.smooth-methods, dtiData,


dti documentation built on May 29, 2017, 3:50 p.m.