Answer: Pixel Puzzle #169

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 = [
    "0000000000",
    "0000000100",
    "1012223000",
    "0023332211",
    "0032222100",
    "0012222200",
    "1122223300",
    "0003332000",
    "0000000000",
    "0000000000",
]
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: 10 × white
• Row 2: 7 × white, 1 × yellow, 2 × white
• Row 3: 1 × yellow, 1 × white, 1 × yellow, 3 × red, 1 × orange, 3 × white
• Row 4: 2 × white, 1 × red, 3 × orange, 2 × red, 2 × yellow
• Row 5: 2 × white, 1 × orange, 4 × red, 1 × yellow, 2 × white
• Row 6: 2 × white, 1 × yellow, 5 × red, 2 × white
• Row 7: 2 × yellow, 4 × red, 2 × orange, 2 × white
• Row 8: 3 × white, 3 × orange, 1 × red, 3 × white
• Row 9: 10 × white
• Row 10: 10 × white