Skip to contents

Generic function to read image meta info given a file

Source: R/all_generic.R, R/file_format.R
read_meta_info-methods.Rd

Reads meta information from image files based on their format (NIFTI or AFNI).

Usage

read_meta_info(x, file_name)

# S4 method for class 'NIFTIFormat'
read_meta_info(x, file_name)

# S4 method for class 'AFNIFormat'
read_meta_info(x, file_name)

Arguments

x

A FileFormat object (either NIFTIFormat or AFNIFormat)

file_name

A character string specifying the file name to read meta information from

Value

A list containing the meta information read from the file.

An object of class NIFTIMetaInfo or AFNIMetaInfo, depending on the input format

Details

These methods use format-specific functions to read the header information and create the appropriate meta information object. The `.read_meta_info` helper function is used internally to streamline the process for both formats.

Examples

# Create a NIFTI format descriptor
fmt <- new("NIFTIFormat",
           file_format = "NIFTI",
           header_encoding = "raw",
           header_extension = "nii",
           data_encoding = "raw",
           data_extension = "nii")

# Read metadata from a NIFTI file
# \donttest{
fname <- system.file("extdata", "global_mask_v4.nii", package="neuroim2")
meta <- read_meta_info(fmt, fname)

# Access metadata properties
dim(meta)          # Image dimensions
#> [1] 64 64 25  4
trans(meta)        # Transformation matrix
#>      [,1] [,2] [,3]   [,4]
#> [1,] -3.5  0.0  0.0  112.0
#> [2,]  0.0  3.5  0.0 -108.0
#> [3,]  0.0  0.0  3.7  -46.2
#> [4,]  0.0  0.0  0.0    1.0
# }