Code Golf: 1x1 black pixel

Answer 1

Postscript, 29 bytes. not really a "single pixel", but it was a single pixel on my preview screen.

0 0 moveto .5 0 lineto stroke

Answer 2

Image file: 10 bytes, in PGM format:

P5 1 1 1\n\0

To create it, in Python: 40 characters

 open('b.pgm', 'w').write('P5 1 1 1\n\0')

Answer 3

The PBM format is a black and white graphics format.

A binary representation of a single black pixel would take 8 bytes, and writing it to a file with C# would look like:

File.WriteAllText("p.pbm", "P4 1 1 ÿ");

Answer 4

Rebmu: 16 chars

en'PNGmkIM![1x1]

If you want it to save to a file based on an argument you pass in, that adds three more chars to the program:

rebmu/args [wrAen'PNGmkIM![1x1]] %my-black-pixel.png

The program is shorthand for the following Rebol, parentheses added for clarity:

write a (encode 'png (make image! [1x1]))

Answer 5

Data URI, 83 characters

data:image/gif;base64,R0lGODlhAQABAIAAAAAAAAAAACH5BAAAAAAALAAAAAABAAEAAAICTAEAOw==

Answer 6

I'm pretty late to this party, but http://www.perlmonks.org/?node_id=7974 has a more general answer than anyone's posted so far:

## tinygif
## World's Smallest Gif
## 35 bytes, 43 if transparent

use strict;
my($RED,$GREEN,$BLUE,$GHOST,$CGI);

## Adjust the colors here, from 0-255
$RED   = 255;
$GREEN = 0;
$BLUE  = 0;

## Set $GHOST to 1 for a transparent gif, 0 for normal
$GHOST = 0;

## Set $CGI to 1 if writing to a web browser, 0 if not
$CGI = 0;

$CGI && printf "Content-Length: %d\nContent-Type: image/gif\n\n", 
  $GHOST?43:35;
printf "GIF89a\1\0\1\0%c\0\0%c%c%c\0\0\0%s,\0\0\0\0\1\0\1\0\0%c%c%c\1\0;",
  144,$RED,$GREEN,$BLUE,$GHOST?pack("c8",33,249,4,5,16,0,0,0):"",2,2,4;