Create an interactive map view of an image

This function allows users to interactively edit and analyze an image using mapview and mapedit packages.

Usage

image_view(
  img,
  object = NULL,
  r = 1,
  g = 2,
  b = 3,
  edit = FALSE,
  alpha = 0.7,
  attribute = "area",
  title = "Edit the image",
  show = c("rgb", "index"),
  index = "B",
  max_pixels = 1e+06,
  downsample = NULL,
  color_regions = custom_palette(),
  quantiles = c(0, 1),
  ...
)

Arguments

img: An Image object.
object: (Optional). An object computed with analyze_objects(). If an object is informed, an additional layer is added to the plot, showing the contour of the analyzed objects, with a color gradient defined by attribute.
r, g, b: The layer for the Red, Green and Blue band, respectively. Defaults to 1, 2, and 3.
edit: If TRUE enable editing options using mapedit::editMap().
alpha: The transparency level of the rectangles' color (between 0 and 1).
attribute: The name of the quantitative variable in the object_index to be used for coloring the rectangles.
title: The title of the map view. Use to provide short orientations to the user.
show: The display option for the map view. Options are "rgb" for RGB view and "index" for index view.
index: The index to use for the index view. Defaults to "B".
max_pixels: integer > 0. Maximum number of cells to use for the plot. If max_pixels < npixels(img), regular sampling is used before plotting.
downsample: integer; for each dimension the number of pixels/lines/bands etc that will be skipped; Defaults to NULL, which will find the best downsampling factor to approximate the max_pixels value.
color_regions: The color palette for displaying index values. Default is custom_palette().
quantiles: the upper and lower quantiles used for color stretching. Set to c(0, 1)
...: Additional arguments to be passed to downsample_fun.

Value

An sf object, the same object returned by mapedit::editMap().

Examples

if (interactive() && requireNamespace("EBImage")) {
# Example usage:
img <- image_pliman("sev_leaf.jpg")
image_view(img)
}