Answer: Pixel Puzzle #337

The hidden picture is a robot!

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 = [
    "0000000110000000",
    "0000000220000000",
    "0000333333330000",
    "0000333333330000",
    "0000333333330000",
    "0000343333430000",
    "0000333333330000",
    "0000333333330000",
    "0000335555330000",
    "0000333333330000",
    "0000066666600000",
    "0000066666600000",
    "0000066666600000",
    "0000066666600000",
    "0000066666600000",
    "0000005005000000",
]
symbols = " #@*o+="

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

When you run it, it prints:

       ##
       @@
    ********
    ********
    ********
    *o****o*
    ********
    ********
    **++++**
    ********
     ======
     ======
     ======
     ======
     ======
      +  +

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: 7 × white, 2 × red, 7 × white
• Row 2: 7 × white, 2 × grey, 7 × white
• Row 3: 4 × white, 8 × purple, 4 × white
• Row 4: 4 × white, 8 × purple, 4 × white
• Row 5: 4 × white, 8 × purple, 4 × white
• Row 6: 4 × white, 1 × purple, 1 × yellow, 4 × purple, 1 × yellow, 1 × purple, 4 × white
• Row 7: 4 × white, 8 × purple, 4 × white
• Row 8: 4 × white, 8 × purple, 4 × white
• Row 9: 4 × white, 2 × purple, 4 × navy, 2 × purple, 4 × white
• Row 10: 4 × white, 8 × purple, 4 × white
• Row 11: 5 × white, 6 × pink, 5 × white
• Row 12: 5 × white, 6 × pink, 5 × white
• Row 13: 5 × white, 6 × pink, 5 × white
• Row 14: 5 × white, 6 × pink, 5 × white
• Row 15: 5 × white, 6 × pink, 5 × white
• Row 16: 6 × white, 1 × navy, 2 × white, 1 × navy, 6 × white