The logo originally

For my blog, I chose to modify my thesis logo (I worked on blue tits (Cyanistes caeruleus) and great tits (Parus major) to measure influence of urbanisation on birds reproduction).

The method of traveling salesperson

I used function writed by Evan Tachovsky and available on her github.

library(imager)
library(dplyr)
library(ggplot2)
library(scales)
library(TSP)

tspDraw <- function(raw_img, point_sample_size, line_color, back_color) {
  
  # load the image and get started
  raw_img <- load.image(raw_img)
  
  # get the sample points
  data <- raw_img %>%
    grayscale() %>%
    as.cimg() %>%
    as.data.frame() %>%
    # adjust the point_sample_size variable to adjust the texture of the tsp image
    # smaller sample looks jagged, large sample looks smooth
    sample_n(size = point_sample_size, weight = (1 - value)) %>%
    select(x, y)
  
  # solve the tsp problem and return a data.frame with the values
  solution <- as.TSP(dist(data)) %>% 
    solve_TSP(method = "arbitrary_insertion") %>%
    as.integer()
  
  order <- data.frame(id = solution) %>%
    mutate(order = row_number())
  
  # join the tsp solution 
  data_to_plot <- data %>%
    mutate(id = row_number()) %>%
    inner_join(order, by = "id") %>%
    arrange(order) %>%
    select(x, y)
  
  
  p <- ggplot(data_to_plot, aes(x, y)) +
    geom_path(color = line_color) +
    scale_y_continuous(trans=reverse_trans())+
    coord_fixed() +
    theme_void() +
    theme(plot.background = element_rect(fill = back_color))
  
  
  return(p)
  
}

My logo

for (n in c(1000, 2000, 4000, 5000))
{
logo <- tspDraw(raw_img = "MesSeb.jpg",
                 point_sample_size = n,
                 line_color = c(1:n), 
                 back_color = "white")
plot(logo)
}

# I chose n=4000 and I save file
ggsave("logo.png", logo)

I thank Antonio Chinchón for his wonderful idea and Eva Tachovsky for her code lines.