perihelions 2 days ago

I know; I mean to say they're larger file sizes—the PNG compression ratio is effectively less than one.

Take the first one, "acius.png", at 84,326 bytes. If you losslessly scale back to the original size (1/4th) and convert to 1-bit NetPBM, it's 51,851 bytes, without compression. I thought that was remarkable.

  • encom 2 days ago

    The PNG files seem to be very poorly compressed.

      $ oxipng -o max --strip all -avZ --fast acius.png
      Processing: acius.png
          2304x2880 pixels, PNG format
          8-bit Indexed (2 colors), non-interlaced
          IDAT size = 84251 bytes
          File size = 84326 bytes
      Transformed image to 1-bit Indexed (2 colors), non-interlaced
      Trying filter None with zopfli, zi = 15
      Found better result:
          zopfli, zi = 15, f = None
          IDAT size = 24466 bytes (59785 bytes decrease)
          file size = 24541 bytes (59785 bytes = 70.90% decrease)
      24541 bytes (70.90% smaller): acius.png