ridgefy.R

library(ggplot2)

url <- "https://ih0.redbubble.net/image.512523322.6908/flat,800x800,075,f.jpg"
file <- tempfile()
download.file(url, file)
im <- jpeg::readJPEG(file)
im <- apply(im, c(1, 2), sum)
im <- im/3
ys <- nrow(im)
xs <- ncol(im)
dimnames(im) <- list(y = seq_len(nrow(im)), x = seq_len(ncol(im)))
im <- reshape2::melt(im)

s <- 10
per  <- 6
a <- s/5
fill <- "#D0DCF2"
im <- subset(im, y %in% seq(1, ys, by = s - 1))
ggplot(im, aes(x)) +
   geom_ribbon(aes(ymin = -y + a*cos(x/max(x)*2*pi*per) - value*s/2, 
                   ymax = -y + a*cos(x/max(x)*2*pi*per) + value*s/2,
                   group = y), fill = fill) +
   scale_x_continuous(expand = c(0, 0)) +
   scale_y_continuous(expand = c(0, 0)) +
   coord_equal() +
   theme_void() +
   theme(plot.background = element_rect(fill = "black"))