Export multiple objects from an image to multiple images

Givin an image with multiple objects, object_export_shp() will split the objects into a list of objects using object_split_shp() and then export them to multiple images into the current working directory (or a subfolder). Batch processing is performed by declaring a file name pattern that matches the images within the working directory.

Usage

object_export_shp(
  img,
  pattern = NULL,
  dir_original = NULL,
  dir_processed = NULL,
  format = ".jpg",
  subfolder = NULL,
  squarize = FALSE,
  nrow = 1,
  ncol = 1,
  buffer_x = 0,
  buffer_y = 0,
  interactive = FALSE,
  parallel = FALSE,
  verbose = TRUE,
  viewer = get_pliman_viewer()
)

Arguments

img: An object of class Image
pattern: A pattern of file name used to identify images to be processed. For example, if pattern = "im" all images in the current working directory that the name matches the pattern (e.g., img1.-, image1.-, im2.-) will be imported and processed. Providing any number as pattern (e.g., pattern = "1") will select images that are named as 1.-, 2.-, and so on. An error will be returned if the pattern matches any file that is not supported (e.g., img1.pdf).
dir_original: The directory containing the original images. Defaults to NULL. It can be either a full path, e.g., "C:/Desktop/imgs", or a subfolder within the current working directory, e.g., "/imgs".
dir_processed: Optional character string indicating a subfolder within the current working directory to save the image(s). If the folder doesn't exist, it will be created.
format: The format of image to be exported.
subfolder: Optional character string indicating a subfolder within the current working directory to save the image(s). If the folder doesn't exist, it will be created.
squarize: Squarizes the image before the exportation? If TRUE, image_square() will be called internally.
nrow: The number of desired rows in the grid. Defaults to 1.
ncol: The number of desired columns in the grid. Defaults to 1.
buffer_x, buffer_y: Buffering factor for the width and height, respectively, of each individual shape's side. A value between 0 and 0.5 where 0 means no buffering and 0.5 means complete buffering (default: 0). A value of 0.25 will buffer the shape by 25% on each side.
interactive: If FALSE (default) the grid is created automatically based on the image dimension and number of rows/columns. If interactive = TRUE, users must draw points at the diagonal of the desired bounding box that will contain the grid.
parallel: If TRUE processes the images asynchronously (in parallel) in separate R sessions running in the background on the same machine. It may speed up the processing time, especially when pattern is used is informed. When object_index is informed, multiple sections will be used to extract the RGB values for each object in the image. This may significantly speed up processing time when an image has lots of objects (say >1000).
verbose: If TRUE (default) a summary is shown in the console.
viewer: The viewer option. If not provided, the value is retrieved using get_pliman_viewer(). This option controls the type of viewer to use for interactive plotting. The available options are "base" and "mapview". If set to "base", the base R graphics system is used for interactive plotting. If set to "mapview", the mapview package is used. To set this argument globally for all functions in the package, you can use the set_pliman_viewer() function. For example, you can run set_pliman_viewer("mapview") to set the viewer option to "mapview" for all functions.

Value

A NULL object.

Examples

if (interactive() && requireNamespace("EBImage")) {
library(pliman)
flax <- image_pliman("flax_leaves.jpg", plot = TRUE)
object_export_shp(flax)

}