Utilities for picking up points in an image

pick_count() opens an interactive section where the user will be able to click in the image to count objects (points) manually. In each mouse click, a point is drawn and an upward counter is shown in the console. After n counts or after the user press Esc, the interactive process is terminated and the number of counts is returned.
pick_coord() Picks coordinates from the image
pick_palette() creates an image palette by picking up color point(s) from the image.
pick_rgb() Picks up the RGB values from selected point(s) in the image.

Usage

pick_count(
  img,
  n = Inf,
  col = "red",
  viewer = get_pliman_viewer(),
  size = 0.8,
  plot = TRUE,
  verbose = TRUE
)

pick_coords(
  img,
  n = Inf,
  col = "red",
  viewer = get_pliman_viewer(),
  size = 0.8,
  verbose = TRUE
)

pick_rgb(
  img,
  n = Inf,
  col = "red",
  viewer = get_pliman_viewer(),
  size = 0.8,
  plot = TRUE,
  verbose = TRUE
)

pick_palette(
  img,
  n = Inf,
  r = 1,
  shape = "box",
  viewer = get_pliman_viewer(),
  show = "rgb",
  title = "Pick colors in the image",
  index = "B",
  random = TRUE,
  width = 100,
  height = 100,
  col = "red",
  size = 0.8,
  plot = TRUE,
  palette = TRUE,
  verbose = TRUE
)

Arguments

img: An Image object.
n: The number of points of the pick_* function. Defaults to Inf. This means that picking will run until the user press Esc.
col, size: The color and size for the marker point.
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.
plot: Call a new plot(img) before processing? Defaults to TRUE.
verbose: If TRUE (default) shows a counter in the console.
r: The radius of neighborhood pixels. Defaults to 1.
shape: A character vector indicating the shape of the brush around the selected pixel. It can be "box", "disc", "diamond", "Gaussian" or "line". Defaults to "box". In this case, if 'r = 1', all the 8 surrounding pixels are sampled. Setting to "disc" and increasing the radius (r) will select surrounding pixels towards the format of a sphere around the selected pixel.
show: How to plot in mapview viewer, either 'rgb or 'index'.
title: The title of the map view when vieweris used.
index: The index to use for the index view. Defaults to 'B'.
random: Randomize the selected pixels? Defaults to TRUE.
width, height: The width and height of the generated palette. Defaults to 100 for both, i.e., a square image of 100 x 100.
palette: Plot the generated palette? Defaults to TRUE.

Value

pick_count() returns data.frame with the x and y coordinates of the selected point(x).
pick_rgb() returns a data.frame with the R, G, and B values of the selected point(s).
pick_palette() returns an object of class Image.

Author

Tiago Olivoto tiagoolivoto@gmail.com

Examples

if (interactive() && requireNamespace("EBImage")) {
library(pliman)
img <- image_pliman("soybean_touch.jpg")

# start a counting process
pick_count(img)

# get rgb from point(s)
pick_rgb(img)

# create a palette from point(s)
pick_palette(img)
}
#> Use the first mouse button to pick up points in the plot.
#> Press Esc to exit.

#> 
#> Use the first mouse button to pick up points in the plot.
#> Press Esc to exit.

#> Error in names(x) <- value: 'names' attribute [3] must be the same length as the vector [0]