csv2tiff.R

library(sf)
library(tidyverse)
library(stars)
library(terra)
library(stringr)
setwd("~/Projects/alproj/")

interpolate <- function(in_path, out_path, res, max_dist, fun=terra::modal) {
  print(str_c("Reading ", in_path, " ......"))
  points <- read_csv(
    in_path
  ) %>%
    st_as_sf(coords = c("x", "y")) %>%
    st_set_crs(6690) %>%
    mutate(z = as.integer(z)) %>%
    select(-c(u, v, z))
  
  print("Rasterizing point data ......")
  ras <- st_rasterize(points, dx = res, dy = res)
  rm(points)
  gc()
  
  ras <- ras %>% 
    as("Raster") %>%
    terra::rast()
  
  times <- ceiling(max_dist / res)
  for (i in 1:times) {
    print(str_c("Interpolating ......", i, " of ", times, " iterations"))
    ras <- ras %>%
      terra::focal(3, fun, na.policy="only", na.rm=TRUE)
  }
  print(str_c("Saving file to ", out_path, " ......"))
  terra::writeRaster(ras, out_path, overwrite=TRUE)
  rm(ras)
  gc()
  print("Finished !")
}

file <- "devel_data/georectified.csv"
out_path <- stringr::str_replace(file, "csv", "tiff")

interpolate(
  file, 
  out_path, 
  1.0, 
  1.0, 
  fun = mean
)