NiftiExtension-class: NiftiExtension Class

In neuroim2: Data Structures for Brain Imaging Data

NiftiExtension Class

Description

Represents a single NIfTI header extension block. NIfTI extensions allow additional metadata to be stored with the image file.

Usage

## S4 method for signature 'NiftiExtension'
show(object)

Arguments

object

A NiftiExtension object.

Details

NIfTI-1.1 extensions follow this structure:

• Bytes 0-3: esize (int32) - total extension size, must be multiple of 16

• Bytes 4-7: ecode (int32) - extension code identifying format

• Bytes 8-(esize-1): edata - the actual extension data

Extensions are chained sequentially after the NIfTI header (byte 352) until the vox_offset is reached.

Slots

ecode

An integer extension code identifying the type of extension. See NiftiExtensionCodes for known codes.

esize

An integer giving the total size of the extension in bytes, including the 8-byte header (esize + ecode). Must be a multiple of 16.

edata

A raw vector containing the extension data (length = esize - 8).

See Also

NiftiExtensionCodes for registered extension codes. NiftiExtensionList-class for a collection of extensions. parse_extension for parsing extension data.

Examples

# Create a simple comment extension
comment_text <- "This is a test comment"
ext <- NiftiExtension(ecode = 6L, data = comment_text)

# Access the extension code
ext@ecode

neuroim2 documentation built on April 16, 2026, 5:07 p.m.