Making pretty blobs

blobs.R

library(magick)
library(tidyverse)

# generate noise and apply morphological transformations to make blobs
blobs <- image_blank(600,400, "black") %>% 
  image_noise("Impulse") %>% 
  image_channel("Green") %>% 
  image_morphology("Dilate", "Diamond:6") %>% 
  image_morphology("Open", "Disk:10", 3) %>% 
  image_blur(10,10) %>% 
  image_threshold("white") %>% 
  image_transparent("black") %>% 
  image_channel("Opacity") %>% 
  image_negate() %>% 
  image_crop(geometry_area(600-10, 400-10, 5,5)) %>% 
  image_border("black", geometry_area(5,5))
blobs

# calculate centroids of the blobs for filling
point_fills <- blobs %>% 
  image_morphology("Thinning", "Skeleton:3", -1) %>% 
  image_morphology("Thinning", "LineEnds", -1) %>%
  image_morphology("Thinning", "Corners", -1) %>% 
  image_morphology("Thinning", "Edges", -1) %>%
  image_raster() %>% 
  dplyr::filter(col!="#000000ff") %>% 
  mutate(col=RColorBrewer::brewer.pal(n(),"Set3"))

# separate blobs
blob_lst <- point_fills %>%
  split(1:nrow(.)) %>% 
  map(~image_fill(blobs, geometry_point(.x$x, .x$y), color = .x$col) %>% 
        image_transparent(.x$col) %>% 
        image_channel("Opacity") %>% 
        image_convert(matte=FALSE) %>% 
        image_transparent("black"))

# calculate required patch sizes
patch_sizes <- blob_lst %>% 
  map(image_trim) %>% 
  map_df(image_info)

# prepare gradiented patches
patches_lst <- patch_sizes %>% 
  bind_cols(point_fills) %>% 
  mutate(width=width*1.5,
         height=height*1.5) %>% 
  select(width, height, col) %>% 
  pmap(~image_blank(..1, ..2, pseudo_image = paste0("gradient:", ..3, "-white")))

# take empty canvas, apply patches where the holes will be be
# bring holes and apply them over patches
res <- map(
  seq_along(blob_lst),
  ~image_composite(image_blank(600,400, color="white"), 
                   patches_lst[[.x]], operator = "Atop",
                   offset = geometry_point(point_fills$x[.x]-patch_sizes$width[.x]/2, 
                                           point_fills$y[.x]-patch_sizes$height[.x]/2))) %>%
  map2(blob_lst, ~image_composite(.x, image_negate(.y), operator="CopyOpacity"))

# animated image
res %>% {Reduce(c,.)}

# flat image
res %>% {Reduce(c,.)} %>% 
  image_flatten() %>% 
  image_transparent("white") %>% 
  image_background("pink")