getKMeansList {colordistance}

Get KMeans clusters for every image in a set

Description

Performs getKMeanColors on every image in a set of images and returns a list of kmeans fit objects, where each dataframe contains the RGB coordinates of the clusters and the percentage of pixels in the image assigned to that cluster.

Usage

getKMeansList(
  images,
  bins = 10,
  sample.size = 20000,
  plotting = FALSE,
  lower = c(0, 0.55, 0),
  upper = c(0.24, 1, 0.24),
  iter.max = 50,
  nstart = 5,
  img.type = FALSE,
  color.space = "rgb",
  from = "sRGB",
  ref.white
)

Arguments

images

A character vector of directories, image paths, or a combination of both. Takes either absolute or relative filepaths.

bins

Number of KMeans clusters to fit. Unlike getImageHist, this represents the actual final number of bins, rather than the number of breaks in each channel.

sample.size

Number of pixels to be randomly sampled from filtered pixel array for performing fit. If set to FALSE, all pixels are fit, but this can be time-consuming, especially for large images.

plotting

Logical. Should the results of the KMeans fit (original image + histogram of colors and bin sizes) be plotted for each image?

lower

RGB triplet specifying the lower bounds for background pixels. Default upper and lower bounds are set to values that work well for a bright green background (RGB [0, 1, 0]).

upper

RGB triplet specifying the upper bounds for background pixels. Default upper and lower bounds are set to values that work well for a bright green background (RGB [0, 1, 0]). Determining these bounds may take some trial and error, but the following bounds may work for certain common background colors:

• Black: lower=c(0, 0, 0); upper=c(0.1, 0.1, 0.1)

• White: lower=c(0.8, 0.8, 0.8); upper=c(1, 1, 1)

• Green: lower=c(0, 0.55, 0); upper=c(0.24, 1, 0.24)

• Blue: lower=c(0, 0, 0.55); upper=c(0.24, 0.24, 1)

If no background filtering is needed, set bounds to some non-numeric value (NULL, FALSE, "off", etc); any non-numeric value is interpreted as NULL.

iter.max

Inherited from kmeans. The maximum number of iterations allowed.

nstart

Inherited from kmeans. How many random sets should be chosen?

img.type

Logical. Should the image extension (.PNG or .JPG) be retained in the list names?

color.space

The color space ("rgb", "hsv", or "lab") in which to cluster pixels.

from

Original color space of images if clustering in CIE Lab space, probably either "sRGB" or "Apple RGB", depending on your computer.

ref.white

The reference white passed to convertColorSpace; must be specified if using CIE Lab space. See convertColorSpace.

Value

A list of kmeans fit objects, where the list element names are the original image names.

Examples

## Not run: 
# Takes a few seconds to run
kmeans_list <- colordistance::getKMeansList(dir(system.file("extdata",
"Heliconius/", package="colordistance"), full.names=TRUE), bins=3,
lower=rep(0.8, 3), upper=rep(1, 3), plotting=TRUE)

## End(Not run)