Answer: Pixel Puzzle #291

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 = [
    "000000000000",
    "000000000000",
    "000011220000",
    "000222111000",
    "302111111100",
    "333311113333",
    "333311223333",
    "001222111100",
    "030111111000",
    "000011110000",
    "000000000000",
    "000000000000",
]
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: 12 × white
• Row 2: 12 × white
• Row 3: 4 × white, 2 × blue, 2 × green, 4 × white
• Row 4: 3 × white, 3 × green, 3 × blue, 3 × white
• Row 5: 1 × yellow, 1 × white, 1 × green, 7 × blue, 2 × white
• Row 6: 4 × yellow, 4 × blue, 4 × yellow
• Row 7: 4 × yellow, 2 × blue, 2 × green, 4 × yellow
• Row 8: 2 × white, 1 × blue, 3 × green, 4 × blue, 2 × white
• Row 9: 1 × white, 1 × yellow, 1 × white, 6 × blue, 3 × white
• Row 10: 4 × white, 4 × blue, 4 × white
• Row 11: 12 × white
• Row 12: 12 × white