MRIaggr (version 1.1.5)

constCompressMRIaggr: Compress a MRIaggr object

Description

Generate from an existing MRIaggr object a new one with lower spatial resolution.

Usage

"constCompressMRIaggr"(object, compression.factor, param = NULL, mask = NULL, threshold = 0.49, verbose = optionsMRIaggr("verbose"))

Arguments

object

an object of class MRIaggr. REQUIRED.

compression.factor

the compression factor. postive integer. REQUIRED.

param

the contrast parameters to load in the new MRIaggr object. character vector or NULL.

mask

the binary contrast parameter(s). character vector.

threshold

the value above which the local mean of the binary parameters is assigned to 1 (and otherwise to 0). numeric between 0 and 1.

verbose

should the execution of the function be traced ? logical.

Value

a MRIaggr object.

Details

ARGUMENTS: Information about the param argument can be found in the details section of initParameter.

FUNCTION: The fonction uses a local mean to compress the initial parameters maps to a lower resolution.

Examples

## load a MRIaggr object
data("MRIaggr.Pat1_red", package = "MRIaggr")
 
## compress the MRIaggr object
MRIaggr.compressed <- constCompressMRIaggr(MRIaggr.Pat1_red, compression.factor = 2,
                                           param = c("DWI_t0","T2_FLAIR_t2","MASK_T2_FLAIR_t2"),
                                           mask = "MASK_T2_FLAIR_t2") 

## display
par(mfrow = c(2,4), mar = rep(1.75,4), mgp = c(2,0.75,0))
multiplot(MRIaggr.Pat1_red, param = "DWI_t0", window = NULL, breaks = seq(0,350,1),
             midplane = TRUE, main = "before - slice ")
multiplot(MRIaggr.compressed, param = "DWI_t0", window = NULL, breaks = seq(0,350,1),
             midplane = TRUE, main = "after - slice ")

multiplot(MRIaggr.Pat1_red, param = "MASK_T2_FLAIR_t2", main = "before - slice ")
multiplot(MRIaggr.compressed, param = "MASK_T2_FLAIR_t2", main = "after - slice ")