pliman (version 3.1.0)

palettes: Create image palettes

Description

image_palette() creates image palettes by applying the k-means algorithm to the RGB values.

Usage

image_palette(
  img,
  pattern = NULL,
  npal = 5,
  proportional = TRUE,
  colorspace = c("rgb", "hsb"),
  remove_bg = FALSE,
  index = "B",
  plot = TRUE,
  save_image = FALSE,
  prefix = "proc_",
  dir_original = NULL,
  dir_processed = NULL,
  return_pal = FALSE,
  parallel = FALSE,
  workers = NULL,
  verbose = TRUE
)

Value

image_palette() returns a list with two elements:

• palette_list A list with npal color palettes of class Image.

• joint An object of class Image with the color palettes

• proportions The proportion of the entire image corresponding to each color in the palette

• rgbs The average RGB value for each palette

Arguments

img

An image object.

pattern

A pattern of file name used to identify images to be imported. 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 as a list. 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).

npal

The number of color palettes.

proportional

Creates a joint palette with proportional size equal to the number of pixels in the image? Defaults to TRUE.

colorspace

The color space to produce the clusters. Defaults to rgb. If hsb, the color space is first converted from RGB > HSB before k-means algorithm be applied.

remove_bg

Remove background from the color palette? Defaults to FALSE.

index

An image index used to remove the background, passed to image_binary().

plot

Plot the generated palette? Defaults to TRUE.

save_image

Save the image after processing? The image is saved in the current working directory named as proc_* where * is the image name given in img.

prefix

The prefix to be included in the processed images. Defaults to "proc_".

dir_original, dir_processed

The directory containing the original and processed images. Defaults to NULL. In this case, the function will search for the image img in the current working directory. After processing, when save_image = TRUE, the processed image will be also saved in such a directory. It can be either a full path, e.g., "C:/Desktop/imgs", or a subfolder within the current working directory, e.g., "/imgs".

return_pal

Return the color palette image? Defaults to FALSE.

parallel

If TRUE processes the images asynchronously (in parallel) in separate R sessions running in the background on the same machine.

workers

A positive numeric scalar or a function specifying the number of parallel processes that can be active at the same time. By default, the number of sections is set up to 30% of available cores.

verbose

If TRUE (default) a summary is shown in the console.

Examples

if (interactive() && requireNamespace("EBImage")) {
library(pliman)
img <- image_pliman("sev_leaf.jpg")
pal <- image_palette(img, npal = 5)
}