Get Started

Getting started with rasterpic is easy: you need an image (png, jpeg/jpg, or tif/tiff) and a spatial object from the sf or terra package to begin.

Basic usage

Here we use the shape of Austria as an example:

library(sf)
library(terra)
library(rasterpic)

# Plot
library(tidyterra)
library(ggplot2)

# Shape and image
x <- read_sf(system.file("gpkg/austria.gpkg", package = "rasterpic"))
img <- system.file("img/vertical.png", package = "rasterpic")

# Create the raster!

default <- rasterpic_img(x, img)

autoplot(default) +
  geom_sf(data = x)

Options

The function provides several options for expansion, alignment, and cropping.

Expand

With this option, the raster extent is expanded beyond the spatial object:

expand <- rasterpic_img(x, img, expand = 1)

autoplot(expand) +
  geom_sf(data = x)

Alignment

Choose the alignment of the image within the spatial extent:

bottom <- rasterpic_img(x, img, valign = 0)

autoplot(bottom) +
  geom_sf(data = x)

Crop and mask

Crop and mask the image:

mask <- rasterpic_img(x, img, crop = TRUE, mask = TRUE)

autoplot(mask)

maskinverse <- rasterpic_img(x, img, crop = TRUE, mask = TRUE, inverse = TRUE)

autoplot(maskinverse)

Supported spatial objects for geotagging

• Spatial objects of the sf package: sf, sfc, sfg, or bbox.
• Spatial objects of the terra package: SpatRaster, SpatVector, SpatExtent.
• A numeric coordinate vector of the form c(xmin, ymin, xmax, ymax).

Supported image formats

rasterpic can parse the following image formats:

• png files.
• jpg/jpeg files.
• tif/tiff files.