downsample: Downsample an Image

Description

This function downsamples a neuroimaging object, reducing its spatial resolution while preserving the temporal dimension.

Usage

downsample(x, ...)
# S4 method for DenseNeuroVec
downsample(x, spacing = NULL, factor = NULL, outdim = NULL, method = "box")
# S4 method for NeuroVec
downsample(x, spacing = NULL, factor = NULL, outdim = NULL, method = "box")
# S4 method for DenseNeuroVol
downsample(x, spacing = NULL, factor = NULL, outdim = NULL, method = "box")
# S4 method for NeuroVol
downsample(x, spacing = NULL, factor = NULL, outdim = NULL, method = "box")

Value

An object of the same class as x, downsampled according to the specified parameters.

Arguments

x: A DenseNeuroVol object to downsample
...: Additional arguments passed to specific downsample methods.
spacing: Target voxel spacing (numeric vector of length 3)
factor: Downsampling factor (single value or vector of length 3, between 0 and 1)
outdim: Target output dimensions (numeric vector of length 3)
method: Downsampling method (currently only "box" for box averaging)

Examples

Run this code

# Create a sample 4D image
data <- array(rnorm(64*64*32*10), dim = c(64, 64, 32, 10))
space <- NeuroSpace(dim = c(64, 64, 32, 10), 
                    origin = c(0, 0, 0),
                    spacing = c(2, 2, 2))
nvec <- DenseNeuroVec(data, space)

# Downsample by factor
nvec_down1 <- downsample(nvec, factor = 0.5)

# Downsample to target spacing
nvec_down2 <- downsample(nvec, spacing = c(4, 4, 4))

# Downsample to target dimensions
nvec_down3 <- downsample(nvec, outdim = c(32, 32, 16))

# Create a sample 3D volume
data <- array(rnorm(64*64*32), dim = c(64, 64, 32))
space <- NeuroSpace(dim = c(64, 64, 32), 
                    origin = c(0, 0, 0),
                    spacing = c(2, 2, 2))
vol <- DenseNeuroVol(data, space)

# Downsample by factor
vol_down1 <- downsample(vol, factor = 0.5)

# Downsample to target spacing
vol_down2 <- downsample(vol, spacing = c(4, 4, 4))

# Downsample to target dimensions
vol_down3 <- downsample(vol, outdim = c(32, 32, 16))

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