README.md

In coolbutuseless/mininetpbm: Write NETPBM PBM/PGM/PPM Images

mininetpbm

mininetpbm is a package for writing vectors, matrices and arrays as NETPBM image files i.e. PGM and PPM formats.

Installation

You can install the released version of mininetpbm from github with:

remotes::install_github('coolbutuseless/mininetpbm')

Outputting a 1D vector as a PGM file

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create an integer matrix and integer vector
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
N       <- 255
int_vec <- rep.int(seq(N), N) %% 256
int_mat <- matrix(int_vec, N, N, byrow = TRUE)
dbl_mat <- int_mat/255


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create a colourful integer array (RGB)
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
r <- int_mat
g <- t(int_mat)
b <- int_mat[, rev(seq(ncol(int_mat)))]

int_arr <- array(c(r, g, b), dim = c(N, N, 3))


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# write the vector as a PGM image file
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
write_pnm(int_mat, "man/figures/mini.pgm")

Outputting a 3D array as a PPM file

write_pnm(int_arr, "man/figures/mini3.ppm")

Benchmark

res <- bench::mark(
  write_pnm(int_arr, filename = "colour_cbu.ppm"),
  png::writePNG(int_arr, target = 'colour_png.png'),
  jpeg::writeJPEG(int_arr, target = 'colour_jpeg.jpg'),
  pixmap::write.pnm(pixmap::pixmapRGB(int_arr), file = 'colour_pixmap.ppm'),
  rtiff::writeTiff(pixmap::pixmapRGB(int_arr), fn = 'colour_rtiff.tiff'),
  imager::save.image(imager::as.cimg(int_arr), file = "colour_cimg.png"),
  imager::save.image(imager::as.cimg(int_arr), file = "colour_cimg.jpg"),
  check = FALSE
)

| expression | mean | median | itr/sec | mem_alloc | | :-------------------------------------------------------------------------- | ------: | ------: | --------: | ---------: | | write_pnm(int_arr, filename = “colour_cbu.ppm”) | 8.23ms | 8.27ms | 121.43736 | 5.21MB | | png::writePNG(int_arr, target = “colour_png.png”) | 4.25ms | 4.08ms | 235.18146 | 220.66KB | | jpeg::writeJPEG(int_arr, target = “colour_jpeg.jpg”) | 2.22ms | 2.07ms | 451.28789 | 214KB | | pixmap::write.pnm(pixmap::pixmapRGB(int_arr), file = “colour_pixmap.ppm”) | 19.5ms | 18.28ms | 51.28101 | 17.21MB | | rtiff::writeTiff(pixmap::pixmapRGB(int_arr), fn = “colour_rtiff.tiff”) | 61.45ms | 61.81ms | 16.27213 | 11.62MB | | imager::save.image(imager::as.cimg(int_arr), file = “colour_cimg.png”) | 24.47ms | 22.9ms | 40.87350 | 26.87MB | | imager::save.image(imager::as.cimg(int_arr), file = “colour_cimg.jpg”) | 16.62ms | 17.02ms | 60.17007 | 25.5MB |

Benchmark results

coolbutuseless/mininetpbm documentation built on May 23, 2019, 5:02 a.m.