ee_utils_gif_save: Write a GIF

In csaybar/rgee: R Bindings for Calling the 'Earth Engine' API

Description

Write a magick-image object as a GIF file using magick package. This function is a wrapper around image_write.

Usage

ee_utils_gif_save(
  image,
  path = NULL,
  format = NULL,
  quality = NULL,
  depth = NULL,
  density = NULL,
  comment = NULL,
  flatten = FALSE
)

Arguments

image	magick image object returned by image_read.
path	path a file, url, or raster object or bitmap array.
format	output format such as "png", "jpeg", "gif", "rgb" or "rgba".
quality	number between 0 and 100 for jpeg quality. Defaults to 75.
depth	color depth (either 8 or 16).
density	resolution to render pdf or svg.
comment	text string added to the image metadata for supported formats.
flatten	should image be flattened before writing? This also replaces transparency with background color.

Value

No return value, called to write a GIF file.

Author(s)

Jeroen Ooms

See Also

Other GIF functions: ee_utils_gif_annotate(), ee_utils_gif_creator()

Examples

## Not run: 
library(rgee)

ee_Initialize()

col <- ee$ImageCollection("JRC/GSW1_1/YearlyHistory")$map(function(img) {
  year <- img$date()$get("year")
  yearImg <- img$gte(2)$multiply(year)
  despeckle <- yearImg$connectedPixelCount(15, TRUE)$eq(15)
  yearImg$updateMask(despeckle)$selfMask()$set("year", year)
})

appendReverse <- function(col) col$merge(col$sort('year', FALSE))

# -----------------------------------
# 1 Basic Animation - Ucayali Peru
# -----------------------------------

bgColor = "FFFFFF" # Assign white to background pixels.
riverColor = "0D0887" # Assign blue to river pixels.

## 1.1 Create the dataset
annualCol = col$map(function(img) {
  img$unmask(0)$
    visualize(min = 0, max = 1, palette = c(bgColor, riverColor))$
    set("year", img$get("year"))
})
basicAnimation <- appendReverse(annualCol)


## 1.2 Set video arguments
aoi <- ee$Geometry$Rectangle(-74.327, -10.087, -73.931, -9.327)
videoArgs = list(
  dimensions = 600, # Max dimension (pixels), min dimension is proportionally scaled.
  region = aoi,
  framesPerSecond = 10
)

## 1.2 Download, display and save the GIF!
animation <- ee_utils_gif_creator(basicAnimation, videoArgs, mode = "wb")
get_years <- basicAnimation$aggregate_array("year")$getInfo()
animation %>%
  ee_utils_gif_annotate("Ucayali, Peru") %>%
  ee_utils_gif_annotate(get_years, size = 15, location = "+90+40",
                        boxcolor = "#FFFFFF") %>%
  ee_utils_gif_annotate("created using {magick} + {rgee}",
                        size = 15, font = "sans",location = "+70+20") ->
  animation_wtxt
gc(reset = TRUE)
ee_utils_gif_save(animation_wtxt, path = paste0(tempfile(), ".gif"))

## End(Not run)

csaybar/rgee documentation built on March 11, 2021, 5:48 a.m.