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Read a tile from an image

Source: R/backend.R
at_tile.Rd

The single, format-independent tile accessor. Returns a numeric array with dimensions [y, x, band] — always three-dimensional, even for a single band.

Usage

at_tile(
  img,
  level = 0L,
  xrange = NULL,
  yrange = NULL,
  bands = NULL,
  call = rlang::caller_env()
)

Arguments

img

An annot_image.

level

Integer pyramid level. Default 0.

xrange, yrange

Optional integer c(min, max) pixel ranges (1-based, inclusive) at level. NULL (default) means the full extent.

bands

Optional integer band indices. NULL (default) means all bands.

call

The calling environment, for error reporting.

Value

A numeric array with dimensions [y, x, band]. An image whose pixel handle was not saved is reopened from its source descriptor; a missing or ambiguous source is an error with code IMAGE_UNAVAILABLE and a changed source IMAGE_CHANGED (see at_inspect_source() and at_relink_source()).

See also

Other images: at_bands(), at_close_image(), at_dims(), at_example_image(), at_hsi_meta(), at_image_capabilities(), at_is_pyramidal(), at_is_spectral(), at_meta(), at_n_bands(), at_n_levels(), at_pixel_size(), at_read_image(), at_wavelengths(), hyperannotatR-classes

Other backends: at_backend_detect(), at_backend_get(), at_backend_list(), at_backend_register(), at_close_image(), at_cubert_export_envi(), at_image_capabilities(), at_read_image(), at_tivita_profile()

Examples

img <- at_example_image("tissue")
dim(at_tile(img, xrange = c(1, 16), yrange = c(1, 16)))
#> [1] 16 16  3