Answer: Pixel Puzzle #350

The hidden picture is a planet with a ring!

The picture as Python

Here is the same picture stored as numbers in a Python list. The program reads each number and prints a symbol for it, so you can see the picture appear in the Python shell.

picture = [
    "0000000000000000",
    "0000000000000000",
    "0000001000000000",
    "0000002222001000",
    "0000222222220000",
    "0000222223330111",
    "0002223332211100",
    "0003332222222000",
    "0002222222223000",
    "0011122223332000",
    "1110223332220000",
    "0000332222220000",
    "0000002222000000",
    "0000000000000000",
    "0000000000000000",
    "0000000000000000",
]
symbols = " #@*"

for row in picture:
    line = ""
    for number in row:
        line = line + symbols[int(number)]
    print(line)

When you run it, it prints:

      #
      @@@@  #
    @@@@@@@@
    @@@@@*** ###
   @@@***@@###
   ***@@@@@@@
   @@@@@@@@@*
  ###@@@@***@
### @@***@@@
    **@@@@@@
      @@@@

Squashing the picture smaller

Computers often save space with a trick called run-length encoding. Instead of storing every pixel, they count how many of the same colour are in a row. Here’s this picture written that way:

Show the run-length code

• Row 1: 16 × white
• Row 2: 16 × white
• Row 3: 6 × white, 1 × yellow, 9 × white
• Row 4: 6 × white, 4 × green, 2 × white, 1 × yellow, 3 × white
• Row 5: 4 × white, 8 × green, 4 × white
• Row 6: 4 × white, 5 × green, 3 × teal, 1 × white, 3 × yellow
• Row 7: 3 × white, 3 × green, 3 × teal, 2 × green, 3 × yellow, 2 × white
• Row 8: 3 × white, 3 × teal, 7 × green, 3 × white
• Row 9: 3 × white, 9 × green, 1 × teal, 3 × white
• Row 10: 2 × white, 3 × yellow, 4 × green, 3 × teal, 1 × green, 3 × white
• Row 11: 3 × yellow, 1 × white, 2 × green, 3 × teal, 3 × green, 4 × white
• Row 12: 4 × white, 2 × teal, 6 × green, 4 × white
• Row 13: 6 × white, 4 × green, 6 × white
• Row 14: 16 × white
• Row 15: 16 × white
• Row 16: 16 × white