addCOG: Add Cloud Optimised Geotiff (COG) to a leaflet map.

In leafem: 'leaflet' Extensions for 'mapview'

Add Cloud Optimised Geotiff (COG) to a leaflet map.

Description

Add Cloud Optimised Geotiff (COG) to a leaflet map.

Usage

addCOG(
  map,
  url = NULL,
  group = NULL,
  layerId = NULL,
  resolution = 96,
  opacity = 0.8,
  options = leaflet::tileOptions(),
  colorOptions = NULL,
  pixelValuesToColorFn = NULL,
  autozoom = TRUE,
  rgb = FALSE,
  imagequery = TRUE,
  imagequeryOptions = NULL,
  ...
)

Arguments

map	the map to add the COG to.
url	url to the COG file to render.
group	he name of the group this raster image should belong to.
layerId	the layerId.
resolution	the target resolution for the simple nearest neighbor interpolation. Larger values will result in more detailed rendering, but may impact performance. Default is 96 (pixels).
opacity	opacity of the rendered layer.
options	options to be passed to the layer. See tileOptions for details.
colorOptions	list defining the palette, breaks and na.color to be used. Currently not used.
pixelValuesToColorFn	optional JS function to be passed to the browser. Can be used to fine tune and manipulate the color mapping. See examples & https://github.com/r-spatial/leafem/issues/25 for some examples. Currently not used.
autozoom	whether to automatically zoom to the full extent of the layer. Default is TRUE
rgb	logical, whether to render Geotiff as RGB. Currently not used.
imagequery	If TRUE a leaflet control with the hovered/clicked value will appear on the map.
imagequeryOptions	additional options for the control panel.
...	currently not used.

Details

This function will overlay Cloud Optimised Geotiff data from a remote url on a leaflet map. Like addGeotiff it uses the leaflet plugin 'georaster-layer-for-leaflet' to render the data. See addGeotiff for a bit more detail what that means.

Value

A leaflet map object.

Examples

if (interactive()) {
  library(leaflet)
  library(leafem)

  base_url = "https://sentinel-cogs.s3.us-west-2.amazonaws.com"
  image_url = "sentinel-s2-l2a-cogs/46/X/DG/2022/8/S2B_46XDG_20220829_0_L2A/L2A_PVI.tif"
  url = sprintf("%s/%s", base_url, image_url)

  leaflet() %>%
    addTiles() %>%
    leafem:::addCOG(
      url = url
      , group = "COG"
      , resolution = 512
      , autozoom = TRUE
    )
}

leafem documentation built on June 8, 2025, 10:09 a.m.