Comment by perihelions

Comment by perihelions 2 days ago

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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
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