Download COIL-20

Download the processed Columbia Object Image Library COIL-20 dataset.

Usage

download_coil20(
  file = NULL,
  cleanup = TRUE,
  verbose = FALSE,
  as = c("data.frame", "list"),
  timeout = 1800
)

Format

If as = "data.frame", the default, a data frame with 16,385 variables:

• x1_y1, x1_y2, ... x1_y128, x2_y1, ... x128_y128: Pixel values ranging from 0 to 1. The x index increases from left to right, and the y index increases from top to bottom, so x1_y1 is top left and x128_y128 is bottom right.

• Label: The object id, stored as a factor with levels 1 to 20.

Row names are "<object>_<pose>", where <object> is the object id and <pose> is the pose id, from 0 to 71.

Arguments

file

File path to download the ZIP archive to. If NULL, a file in a temporary work directory is used.

cleanup

If TRUE, delete temporary download and extraction files before returning. If file is supplied, only the downloaded ZIP and the dedicated extraction directory are removed.

verbose

If TRUE, log download and extraction progress.

as

Return format. Use "data.frame" for the original wide data frame shape, or "list" for the canonical image result described in download_mnist().

timeout

Minimum download timeout in seconds. The default is 30 minutes; a larger existing global R timeout is preserved.

Value

If as = "data.frame", a data frame containing the COIL-20 dataset. If as = "list", a canonical image result with object ids, poses, and factor labels in meta.

Details

Downloads and expands the processed COIL-20 ZIP archive and converts the PNG files to a data frame or canonical list result. COIL-20 contains 20 objects, each represented by 72 grayscale poses. Each image has resolution 128 x 128.

The optional png package is required when reading the downloaded PNG files.

References

The Columbia Object Image Library COIL-20 https://cave.cs.columbia.edu/repository/COIL-20

Examples

if (FALSE) { # \dontrun{
coil20 <- download_coil20(verbose = TRUE)
show_coil_object(coil20, object = 5, pose = 4)
} # }