Read The world’s smallest PNG. The post could be short introduction into PNG format. Here are the world’s smallest PNG zoomed 200x times. It’s just one black pixel.

The world's smallest PNG

Here is hex dump of the image:

% xxd world\'s\ smallest\ PNG.png
00000000: 8950 4e47 0d0a 1a0a 0000 000d 4948 4452  .PNG........IHDR
00000010: 0000 0001 0000 0001 0100 0000 0037 6ef9  .............7n.
00000020: 2400 0000 0a49 4441 5478 0163 6000 0000  $....IDATx.c`...
00000030: 0200 0173 7501 1800 0000 0049 454e 44ae  ...su......IEND.
00000040: 4260 82                                  B`.

Browsed shortly Portable Network Graphics (PNG) Specification (Third Edition).

TIL xcbeautify tool for making xcodebuild’s output more readable.