leafem (version 0.2.3)

addCOG: 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,
  ...
)

Value

A leaflet map object.

Arguments

map

the map to add the COG to.

url

url to the COG file to render.

group

he name of the group this COG 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

image opacity.

options

see [leaflet](tileOptions).

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.

...

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.

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
    )
}