51
\$\begingroup\$

So, I want you to make a PNG image that says "Hello world!" and nothing else on a distinguishable background using only an image making API (eg ImageMagick) and return the image. Fewest characters win, as usual. Oh, and you can use any color text.

\$\endgroup\$
8
  • \$\begingroup\$ Does it have to output Hello World or Hello World!? \$\endgroup\$ Commented Feb 2, 2014 at 12:55
  • 3
    \$\begingroup\$ @ryan Hello World! is the right one. \$\endgroup\$
    – figgyc
    Commented Feb 2, 2014 at 14:52
  • 3
    \$\begingroup\$ A lot of answers could save one character by replacing the double 'l' in 'hello' with the medieval Welsh ligatures 'Ỻ' or 'ỻ': once the chars have been transformed to pixels it shouldn't matter what their origin was as long as people still perceive 'heỻo world!' as 'hello world!'. \$\endgroup\$
    – timxyz
    Commented Feb 3, 2014 at 11:27
  • 9
    \$\begingroup\$ @poldie Your browser changes PNG based on how the pixels got in there? \$\endgroup\$ Commented Feb 4, 2014 at 2:22
  • 2
    \$\begingroup\$ @timxyz For me, ỻ is rendered as a box containing 1EFB. I tried to use it in my program anyway, and the result was a square. So, this is probably not very portable. \$\endgroup\$ Commented Feb 4, 2014 at 5:24

41 Answers 41

58
\$\begingroup\$

Bash + ImageMagick: 35 33

Default font, default text size, default colours:

convert label:Hello\ world! a.png

and here's the result:

Hello, World!

Thanks to DigitalTrauma and sch for the help :-D

\$\endgroup\$
14
  • 14
    \$\begingroup\$ Great!! :-) I wanted to write something like that. Unbeatable! All the esoteric languages will finally get their ass kicked today! :-) \$\endgroup\$
    – Tomas
    Commented Feb 1, 2014 at 20:57
  • 7
    \$\begingroup\$ convert label:Hello\ world! a.png is even shorter. \$\endgroup\$
    – sch
    Commented Feb 1, 2014 at 22:10
  • 5
    \$\begingroup\$ Also, if you make it sh, you don't have to worry about ! and you make it even less esoteric. \$\endgroup\$
    – sch
    Commented Feb 1, 2014 at 22:17
  • 4
    \$\begingroup\$ Frankly I don't think bash qualifies as a programming language here or that convert qualifies as an API. But in this case I'd throw GNU hello in and bring this contraption down to 29 with: convert label:"`hello`" h.png \$\endgroup\$ Commented Feb 4, 2014 at 9:43
  • 3
    \$\begingroup\$ Why do you even care for the extension of the file? Just call it a and the mime type will do the rest. \$\endgroup\$ Commented Feb 4, 2014 at 12:52
45
\$\begingroup\$

Mathematica 28 27

This creates and exports the sentence, "Hello world!", as a PNG image. 1 char saved by Mechanical snail.

".png"~Export~"Hello world!"

Testing

This imports the PNG image. The image was enlarged by dragging the image box handles.

png

\$\endgroup\$
2
  • 4
    \$\begingroup\$ 27 bytes: ".png"~Export~"Hello world!" \$\endgroup\$ Commented Feb 2, 2014 at 7:57
  • 9
    \$\begingroup\$ Wow, two snails in a race! :-) \$\endgroup\$
    – Tomas
    Commented Feb 5, 2014 at 9:50
31
\$\begingroup\$

HTML, 1494

I know this won't win, but I didn't see this here before.

data:image/png;base64,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

Well apparently StackExchange will not allow data links so you must copy & paste it into your browser's address bar.


@squeamish ossifrage got it down to 176:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAC0AAAAHAQAAAAC0VvlnAAAAOklEQVR4nGLIv/57/+9rDGDqAkPOterN0YIM3KG712pdZcgI3bW26gZD9lUwlRNWW1wtAAAAAP//AwCcyhjs3+7tWQAAAABJRU5ErkJggg

114

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACUAAAAEAQAAAAAhFcs9AAAAIElEQVQIHWOJit1f7szy58v9DAWWPaEMP7hZHHgi1aMB

@primo got it down to 112:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACYAAAAEAQAAAADKInA+AAAAH0lEQVR4nGOIj///7wVDZOBdoQ4G4dCrYWuA7JNiHQ
\$\endgroup\$
11
  • 5
    \$\begingroup\$ You can easily compress this to 258 characters: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAEIAAAANCAAAAAA4MeeNAAAAdklEQVR4Ac2QUQqFQAwDc9I5Ze6XB8HXXRFE8Mdg+zGEwa7yOurXdUb30ap+UIHkUSDRGg5K5D+SdRQ8iqbdTjmk043ihcQU9r8Y1aEY2A2Y1cte4KRIc1UYg58oIFYuhwQ5UgYp+yF+8Jz1Qgapsz/n23xE8QNxUbxuz+WqjAAAAABJRU5ErkJggg== pastebin.com/5TQzNv3D \$\endgroup\$
    – MMM
    Commented Feb 3, 2014 at 16:03
  • 2
    \$\begingroup\$ @squeamish ossifrage got it down to 176: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAC0AAAAHAQAAAAC0VvlnAAAAOklEQVR4nGLIv/57/+9rDGDqAkPOterN0YIM3KG712pdZcgI3bW26gZD9lUwlRNWW1wtAAAAAP//AwCcyhjs3+7tWQAAAABJRU5ErkJggg. Must strip the hidden spaces. \$\endgroup\$
    – Chloe
    Commented Feb 4, 2014 at 3:48
  • 1
    \$\begingroup\$ 143 chars: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACUAAAAEAQAAAAAhFcs9AAAAIElEQVQIHWOJit1f7szy58v9DAWWPaEMP7hZHHgi1aMBegAI03/J+AQAAAAASUVORK5CYII= \$\endgroup\$
    – luxcem
    Commented Feb 4, 2014 at 10:54
  • 1
    \$\begingroup\$ I got it down to 135 characters! data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACUAAAAEAQAAAAAhFcs9AAAAIElEQVQIHWOJit1f7szy58v9DAWWPaEMP7hZHHgi1aMBegAI03/J+AQAAAAASUV= (btw, that's 83bytes for a png image that says "Hello World", thought I might throw that out there!) \$\endgroup\$ Commented Feb 6, 2014 at 5:15
  • 2
    \$\begingroup\$ Valid png format - 140 bytes codepad.org/O0TwZbKF. No IEND - 124 bytes: codepad.org/QdutLeK1. No IEND, no IDAT crc32, no zlib adler32 - 112 bytes: codepad.org/R4srHxhh. \$\endgroup\$
    – primo
    Commented Feb 6, 2014 at 10:29
28
\$\begingroup\$

C# - 168 chars

C# is better! ;)

using System.Drawing;class a{static void Main(){var s=new Bitmap(99,9);Graphics.FromImage(s).DrawString("Hello world!",new Font("",5),Brushes.Red,0,0);s.Save(".png");}}

Saves as .png in the current directory.

Rule abuse:

  • Minimum font/image size has not been specified, so I settled for the minimum readable ;)
  • Filename is empty (only extension!), but it works flawlessly.

To mirror the Java answer, here is the indented code:

using System.Drawing;
class a
{
    static void Main()
    {
        var s = new Bitmap(99, 9);
        Graphics.FromImage(s).DrawString("Hello world!", new Font("", 5), Brushes.Red, 0, 0);
        s.Save(".png");
    }
}

.net's API is a lot cleaner.

\$\endgroup\$
10
  • \$\begingroup\$ Thanks for the suggestion of making the file call just .png. :) \$\endgroup\$ Commented Feb 1, 2014 at 22:08
  • \$\begingroup\$ I don't see how this is much cleaner than the Java one. \$\endgroup\$ Commented Feb 3, 2014 at 1:48
  • \$\begingroup\$ It is much cleaner than the Java one. \$\endgroup\$ Commented Feb 3, 2014 at 8:10
  • 6
    \$\begingroup\$ @immibis I can point the following: Character count is 28% lower, because of: no checked exceptions(throws Exception); the var keyword; Save is a method of the image itself, in contrast to javax.imageio.ImageIO.write(b...; file type is automagically inferred from the extension, no need to specify a separate "png"; No need to instantiate a File object as in new java.io.File("p"); Main method doesn't need to receive a parameter. The general idea is the same: create an image, use Graphics to write to it, and save it - but here it is done with more clear and succint method calls. \$\endgroup\$ Commented Feb 3, 2014 at 9:33
  • \$\begingroup\$ But C# doesn't have wildcards in generics. And anonymous classes. And return type covariance. And some other things I'm too lazy to recall. \$\endgroup\$ Commented Feb 4, 2014 at 23:47
25
\$\begingroup\$

Linux shell + various utilities: 48 bytes

My first thought was to print Hello World! in the console, and then take a screenshot (after a small delay to avoid the race condition) using scrot:

echo Hello World\!;scrot -d1

(28 bytes). Unfortunately, this fails the "and nothing else" requirement: it will generally show other things like window decorations.

So instead, do it inside a full-screen xterm. This covers up any other windows and hides window decorations. It also satisfies the background-color requirement, since xterm defaults to a white background.

Because xterm displays a black cursor, we also need to tell it to hide the cursor. That can be accomplished using a terminal escape sequence: ESC [ ? 2 5 l.

The option to make it full-screen is -fullscreen. However, it seems to work if you abbreviate the option to the shortest unambiguous possibility, -fu, saving 8 bytes.

The final code (48 bytes) is:

xterm -fu -e 'echo \x1b[?25lHello World!;scrot -d1'

(where \x1b denotes a literal ESC character, which takes 1 byte). By default, scrot writes the screenshot to a timestamped PNG file in the current directory.

It works on my system:

output

\$\endgroup\$
1
  • \$\begingroup\$ You missed some scrot options - I often use -s (interactively select window), but in this case you can use -u to grab the current (focused) window only. \$\endgroup\$
    – bryn
    Commented Feb 4, 2014 at 19:36
19
\$\begingroup\$

Processing, 38 37

This might be considered cheating, but:

text("HeΠo World!",9,8);save(".png");

enter image description here


38 char solution:

text("Hello World!",9,9);save(".png");

Saves this image as .png:

enter image description here

\$\endgroup\$
0
14
\$\begingroup\$

Java - 340 339 292 261 239 236 233 chars

This outputs a file just called p with a transparent background and white text:

import java.awt.image.*;class R{public static void main(String[]y)throws Exception{BufferedImage b=new BufferedImage(80,9,2);b.getGraphics().drawString("Hello World!",5,9);javax.imageio.ImageIO.write(b,"png",new java.io.File("p"));}}

Here a properly-indented version. Should be pretty clear what is going on:

import java.awt.image.*;

class R {
    public static void main(String[] y) throws Exception {
        // 2 = BufferedImage.TYPE_INT_ARGB
        BufferedImage b = new BufferedImage(80, 9, 2);
        b.getGraphics().drawString("Hello world!", 5, 9);
        javax.imageio.ImageIO.write(b, "png", new java.io.File("p"));
    }
}

You might argue that white text in a transparent background is awful for reading and the file being called just p without the .png extension is awful too. So this longer variant version with 290 chars use red text and outputs a file called p.png:

import java.awt.image.*;import java.awt.*;class R{public static void main(String[]y)throws Exception{BufferedImage b=new BufferedImage(80,9,2);Graphics g=b.getGraphics();g.setColor(Color.RED);g.drawString("Hello world!",5,9);javax.imageio.ImageIO.write(b,"png",new java.io.File("p.png"));}}

That properly-indented:

import java.awt.image.*;
import java.awt.*;

class R {
    public static void main(String[] y) throws Exception {
        // 2 = BufferedImage.TYPE_INT_ARGB
        BufferedImage b = new BufferedImage(80, 9, 2);
        Graphics g = b.getGraphics();
        g.setColor(Color.RED);
        g.drawString("Hello world!", 5, 9);
        javax.imageio.ImageIO.write(b, "png", new java.io.File("p.png"));
    }
}
\$\endgroup\$
15
  • 2
    \$\begingroup\$ @user-12506 Yes, you can add throws Exception to other methods, but the compiler enforce this rule: if you call a method that might throw a Throwable that is not a RuntimeException or an Error, then the compiler will require that you either catch or rethrow it, and this includes Exception. Further, although it is allowed, declaring throws Exception is a bad programming practice, because Exception is way too generic to be effectively handled in practice and rethrowing it just spread the bad practice to elsewhere. \$\endgroup\$ Commented Feb 3, 2014 at 8:22
  • 1
    \$\begingroup\$ @user-12506 It's called checked exceptions. Look it up. :) \$\endgroup\$
    – ntoskrnl
    Commented Feb 3, 2014 at 14:05
  • 1
    \$\begingroup\$ @user-12506 Not everything is lower case in Java – classes are CamelCase just like in C#. Methods and fields are lowerCamelCase, and packages are alllowercase. Makes it somewhat easier to determine what a name refers to, in my opinion. \$\endgroup\$
    – ntoskrnl
    Commented Feb 3, 2014 at 20:55
  • 1
    \$\begingroup\$ @ntoskrnl Yeah, things can and do get a bit confusing when classes, methods and other things are camel case. But in the case of methods, it either begins with an Identifier that allows you to immediately recognize it as such, and if you're calling a method, you'll know right away that it's a method because it ends in (); or (somethinginHere);. In C#, most things are CamelCase (when I'm typing anyway), except for variables. and (most) types. Either way, I'm going to have to get used to Java eventually. I've just started my first serious Android project. \$\endgroup\$ Commented Feb 3, 2014 at 21:02
  • 2
    \$\begingroup\$ @Timtech, at least for me ỻ was rendered as a square in the resulting image. Here in the browser (using firefox), it renders as a box containing 1EFB. I strongly suspect that this is not portable. \$\endgroup\$ Commented Feb 4, 2014 at 5:19
14
\$\begingroup\$

Fortran 90, 104 94 bytes:

Aight, game on. Fortran 90, using the g2 graphics library and implict typing, so "d" is a real:

d=g2_open_gd('h',80.,12.,g2_gd_png)
call g2_string(d,1,1,'Hello world!')
call g2_close(d)
end

Needs to have the g2 library installed, then just compile with

gfortran -lg2 -fsecond-underscore p.f90

Thanks Kyle Kanos for suggesting to drop "program p"!

I'm pretty satisfied that I beat C#, C + Cairo, Java, Javascript, Python and Ruby! And now also Perl!

Example output: example PNG produced by Fortran

\$\endgroup\$
1
  • 1
    \$\begingroup\$ This can be shortened to 93 characters by eliminating program p as it is not necessary (the only necessary part of a F90 code is end). \$\endgroup\$
    – Kyle Kanos
    Commented Feb 4, 2014 at 16:39
11
\$\begingroup\$

R, 52 39 chars

png()
frame()
text(.5,1,"Hello World!")

Saves as Rplot001.png in current directory. To be run as a script in non-interactive (batch) mode.

Thanks to Sven Hohenstein and Michael Hoffman for updates!

\$\endgroup\$
3
  • \$\begingroup\$ I count 52 characters... \$\endgroup\$ Commented Feb 2, 2014 at 2:47
  • \$\begingroup\$ @SvenHohenstein sorry you are correct. I made a mistake while attempting shorter versions (they didn't work). \$\endgroup\$
    – Tomas
    Commented Feb 2, 2014 at 3:08
  • 1
    \$\begingroup\$ dev.off() is unnecessary when you run this as a script instead of interactively. \$\endgroup\$ Commented Feb 3, 2014 at 18:12
10
\$\begingroup\$

PHP + gd2 - 86 bytes

<?imagestring($i=imagecreatetruecolor(97,16),4,2,0,'Hello world!',65535);imagepng($i);

imagecreatetruecolor is used instead of the shorter imagecreate, because colors can used directly without having to allocate them with imagecolorallocate. 65535 corresponds to hex color #00FFFF, a.k.a. cyan. I could have used 255 for blue, but it's fairly hard to see on a black canvas.


If the requirement that the background must be white or transparent is to be strictly enforced, I think the best that can be done is 98 bytes:

<?imagestring($i=imagecreatetruecolor(97,16),4,2,0,'Hello world!',imagefilter($i,0));imagepng($i);

The 0 sent to imagefilter is the value of the constant IMG_FILTER_NEGATE, which of course negates the image. The result, 1, is then used as the paint color (#000001):


Another option at 108 bytes:

<?imagestring($i=imagecreatetruecolor(97,16),4,2,imagecolortransparent($i,0),'Hello world!',1);imagepng($i);

Setting black to be transparent, and drawing with #000001 instead.


PHP + No Library - 790+ bytes

<?
echo pack('CA3N2',137,'PNG',218765834,13);
echo $ihdr = pack('A4N2C5','IHDR',45,7,1,0,0,0,0);
echo hash('crc32b',$ihdr,true);
$data =
  '--------0  0      0 0                        0    0 0---'.
  '--------0  0      0 0                        0    0 0---'.
  '--------0  0  00  0 0  00    0   0  00  0 0  0  000 0---'.
  '--------0000 0  0 0 0 0  0   0   0 0  0 00 0 0 0  0 0---'.
  '--------0  0 0000 0 0 0  0   0 0 0 0  0 0    0 0  0 0---'.
  '--------0  0 0    0 0 0  0   0 0 0 0  0 0    0 0  0  ---'.
  '--------0  0  000 0 0  00     0 0   00  0    0  000 0---';
$bytes = join(array_map(chr,array_map(bindec,str_split(strtr($data,' -',10),8))));
$cmp = gzcompress($bytes);
echo pack('N',strlen($cmp));
echo $idat = 'IDAT'.$cmp;
echo hash('crc32b',$idat,true);
echo pack('NA4N',0,'IEND',2923585666);

Ahh, that's better. No bloat; exactly as much as required, and not a chunk more.
The result is this 109 byte png:

Or, URI encoded (which seems to be trending...) at 168 bytes:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAC0AAAAHAQAAAAC0VvlnAAAANElEQVR4nGPIv/7//+8LDFAq51r15mgBBu7Q3Wu1LjBkhO5aW3WBIfsqkLrBkBNWW1wtAACw2RlgLInRogAAAABJRU5ErkJggg

Supposing we wanted to cut that down a bit more, let's say we replace the data string with this:

$data =
  '--------0  0      0 0                    0   0 0'.
  '--------0  0  00  0 0 000   0   0 000 00 0 000 0'.
  '--------0000 0 00 0 0 0 0   0 0 0 0 0 0  0 0 0 0'.
  '--------0  0 00   0 0 0 0   0 0 0 0 0 0  0 0 0  '.
  '--------0  0  000 0 0 000   00 00 000 0  0 000 0';

(and update the header to the new dimensions, 40x5), the output would be this 96 byte png:

Which URI encodes to 150 bytes:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAFAQAAAAAft5MoAAAAJ0lEQVR4nGPIv/7//y6GnCvlLosYuEJLQ1cxZF4tDV3NkBNS5LoIANqBDTt5Av0NAAAAAElFTkSuQmCC

I think that's about as small as you're going to be able to get, and still be considered "human readable".


Further Analysis

You may have noticed that we've been toting along an extra byte at the beginning of each scanline (denoted by --------). This isn't solely for decoration. Each byte specifies the filtering used by each scanline. According to the PNG specification, "Filtering transforms the PNG image with the goal of improving compression." So let's try that.

The are five different filtering operations which can be applied independently to each scanline. The PHP implementation that I used for each can be seen here: http://codepad.org/xCQpBPC3 where $bytes represents the raw bytes for the current scanline, and $prior represents the raw, unfiltered bytes for the scanline above the current.

Let's start with the first 45x7 image. Seven scanlines each with 5 different filterings makes 78125 different possibilities to grind through. The initial encoding of the data block was 52 bytes in length, and after a bit of grinding zlib found a one byte improvement using filtering pattern [1, 1, 1, 1, 0, 0, 0] (that is, the first four scanlines with Sub filtering, and the last three unfiltered). The result is this 108 byte png:

Which of course looks identical to the last. But I'm not convinced that zlib is producing the best possible encoding, and I think i have good reason to be skeptical. I decided to try AdvanceComp (which uses the same DEFLATE engine used for 7-zip), and Zopfli, an implementation which claims to "find a low bit cost path through the graph of all possible deflate representations." Sure enough, Zopfli mananged to compress the same data data pattern [1, 1, 1, 1, 0, 0, 0] down to 50 bytes, producing this 107 byte png:

Once again, visually identical. (As a point of interest, it should probably be mentioned at this point that AdvanceComp with the setting -z3 (compress-extra (7z)) didn't manage to find anything shorter than 60 bytes - the data was left uncompressed. It seems it refuses to compress anything this short). The above URI encodes to 165 bytes:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAC0AAAAHAQAAAAC0VvlnAAAAMklEQVR4AWPMz9Bg+HMVRuVkLbVYsZWR2yvtU+0yhozQXWurLjBkXwVSNxhywmqLqwUA+IMVKa7QjrYAAAAASUVORK5CYII

Fully 11 bytes shorter than squeamish ossifrage's attempt at more or less an identical image.

Onwards to the 40x5 image. Five lines with 5 filterings each means we only have 3125 possibilities this time. The original encoding was 39 bytes in length, and with a bit of grinding, zlib found quite a few 38s. The one I've chosen is [1, 0, 0, 2, 0], which contains the largest number of unfiltered lines, and Sub and Up filters on lines 0 and 4, which are the simplest. Zopfli wasn't able to improve this result any further. The result is this 95 byte png:

Which URI encodes to 149 bytes:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAFAQAAAAAft5MoAAAAJklEQVR4nGPMz9Bg2M2Qc6XcZREDV2hp6Cqm+AYGBkaGnJAi10UAju4JJ/1zkEIAAAAASUVORK5CYII

You might be tempted to think that the last 18 or so bytes of this aren't necessary. After all, this 121 byte URI will still display correctly, at least in Chromium:

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAFAQAAAAAft5MoAAAAIUlEQVR4nGPMz9Bg2M2Qc6XcZREDV2hp6Cqm+AYGBkaGnJAi10U

But if you save it to a file, it will break in very many image viewers. In fact, any compliant decoder is required to report an error. So what have we chopped off?

From end towards beginning:

  • 4 bytes - CRC32 for IEND chunk (always 0xAE426082)
  • 4 bytes - IEND chunk marker (always IEND)
  • 4 bytes - IEND chunk length (always 0x00000000)
  • 4 bytes - CRC32 for IDAT chunk
  • 4 bytes - Adler32 for zlib data
  • 1 byte - Stop marker for zlib data

Additionally adjusting the IDAT length marker down by 5 (to compensate for the bytes we deleted) seems to "fix" the image in Windows Previewer.

\$\endgroup\$
2
  • \$\begingroup\$ The question state that it should have a white or transparent background. I myself think that the rules should be relaxed to allow black too, but for now, it fails the spec at this point. \$\endgroup\$ Commented Feb 2, 2014 at 5:25
  • \$\begingroup\$ @Victor Unfortunately, the gd2 library - as exposed by PHP, at least - doesn't have an option to specify the default color. Setting black to be transparent does work, though. Or simply to negate the entire image before adding the text. \$\endgroup\$
    – primo
    Commented Feb 2, 2014 at 6:08
9
\$\begingroup\$

C + Cairo: 238 221 202 bytes

#include <cairo/cairo.h>
main(){cairo_surface_t*s=cairo_image_surface_create(0,99,50);cairo_t*c=cairo_create(s);cairo_move_to(c,0,9);cairo_show_text(c,"Hello world!");cairo_surface_write_to_png(s,"o");}

$ cc `pkg-config cairo --libs --cflags` mini.c && ./a.out && display o

Here is the un-minified version:

#include <cairo/cairo.h>
void main (int argc, char* argv[])
{
    cairo_t *cr;
    cairo_surface_t *surf;
    surf = cairo_image_surface_create (0, 99, 50);
    cr = cairo_create (surf);
    cairo_move_to (cr, 0, 9);
    cairo_show_text (cr, "Hello world!");
    cairo_surface_write_to_png (surf, "out.png");
}

Best enjoyed while listening to this song :)

\$\endgroup\$
4
  • \$\begingroup\$ You can save some chars by removing the type declaraction, i.e. the void for main and the int for x, and possibly the char for **a (I'm not sure about the last one though). In C the type is default to be int if no type is specified, and you don't necessarily need to return a value for int main. This may produce compilation warning messages, but not errors and the program will still work. \$\endgroup\$
    – user12205
    Commented Feb 2, 2014 at 10:54
  • 1
    \$\begingroup\$ Shaved 17 bytes by removing the pointless #define C(n,...) …. Also, main returns int, not void (and as of C99 it's not required to explicitly "return 0" at the end of main; the implementation implicitly adds it for you). \$\endgroup\$ Commented Feb 3, 2014 at 2:09
  • \$\begingroup\$ @ace Thank you! I had forgotten that types defaults to int i C. But it looks like it's all-or-nothing; you can't have some variables in the call signature use default types while others don't. So I just changed it to main() and hardcode the filename to o instead of passing it to main. Now it's smaller than the Java version :) \$\endgroup\$ Commented Feb 3, 2014 at 2:35
  • \$\begingroup\$ @Quuxplusone Thanks! Did not know that C99 add an implicit return 0 to main if not already there. That was why I choose to (incorrectly) return void instead of int. Since you got rid of the vararg macro, C99 is not required to compile the code anymore. <rant>Which makes it more portable to compilers who's vendors has chosen to not implement C99 [read: Microsoft] :)</rant> \$\endgroup\$ Commented Feb 3, 2014 at 2:45
9
\$\begingroup\$

make a PNG image that says "Hello world!" …

You'll hopefully excuse my very loose interpretation of the above requirement. :)

OSX bash:

printf '"Hello world!" and nothing else on a distinguishable background using only an image making API (eg ImageMagick) and return the image.' > hello.png
say -f hello.png
\$\endgroup\$
5
  • \$\begingroup\$ But it's not a PNG image, is it? \$\endgroup\$
    – Ruslan
    Commented Feb 4, 2014 at 10:58
  • 2
    \$\begingroup\$ Well, it's technically a .png file, and it does say what is needed. :-) \$\endgroup\$ Commented Feb 4, 2014 at 11:26
  • 1
    \$\begingroup\$ PNG image is not "ASCII text, with no line terminators", as said by file. It's a .png file, but not PNG image. \$\endgroup\$
    – Ruslan
    Commented Feb 4, 2014 at 11:28
  • 2
    \$\begingroup\$ Fail point. I didn't manage to find a way to fool the file utility by pre-pending the whole thing with the relevant code (i.e. decimals 137 80 78 71 13 10 26 10). Perhaps you might know of a way? ;-) \$\endgroup\$ Commented Feb 4, 2014 at 12:27
  • \$\begingroup\$ seems you'd need to make full header with all information like dimensions, palette etc., because file prints this information. With your relevant code it only says "data". \$\endgroup\$
    – Ruslan
    Commented Feb 4, 2014 at 14:47
9
\$\begingroup\$

Javascript! 105 104 101

c=document.createElement('canvas');open(c.toDataURL(c.getContext('2d').fillText('Hello world!',0,9)))

Outputs this size-optimized and pretty image:

Hello world!

\$\endgroup\$
9
\$\begingroup\$

Octave, 47

axis('off')
title("Hello World!")    
print -dpng x.png

\$\endgroup\$
2
  • \$\begingroup\$ -1 until you remove the axes (I think it would be axis('off'), not sure, see here) It would also be nice if you attached the generated output as well. \$\endgroup\$
    – Nick T
    Commented Feb 6, 2014 at 20:58
  • \$\begingroup\$ +1 now :D why bother keeping the bigger/broken ones though... \$\endgroup\$
    – Nick T
    Commented Feb 11, 2014 at 3:28
8
\$\begingroup\$

Sage notebook, 22

text("Hello world",0j)
\$\endgroup\$
2
  • \$\begingroup\$ Does this produce a PNG image? \$\endgroup\$
    – Timtech
    Commented Feb 4, 2014 at 1:02
  • \$\begingroup\$ Yup. That's why I specified 'notebook', the CLI pops a window open, but the notebook saves a .png for the browser to display. \$\endgroup\$
    – boothby
    Commented Feb 4, 2014 at 6:31
8
\$\begingroup\$

Ruby, 138

I'm golfing this hole with just my putter. (I chose a PNG library without fonts or a string draw method.)

require'chunky_png';i=ChunkyPNG::Image.new 34,4
136.times{|v|i[*(v.divmod(4))]=9*(0xb0fae0f02e0eae0ece00eae0f0f0bf0f2f&1<<v)>>v};i.save ?h

Actual output is 34x4 pixels. (Enlarged below.) This plots very, very small and nearly transparent hand-drawn chars onto a very small transparent background. Image is saved to a PNG file named h.

output

\$\endgroup\$
2
  • \$\begingroup\$ Would it be shorter in Ruby to store 0xb0... in Base64 and call a decode function? \$\endgroup\$ Commented Feb 2, 2014 at 10:10
  • 1
    \$\begingroup\$ @Mechanicalsnail, I think that would require another require and then some, so the savings would be blown. I think. I did look at Base 36 (since that can be done with to_i alone) but that ends up a bit longer. \$\endgroup\$ Commented Feb 2, 2014 at 10:14
8
\$\begingroup\$

TI-BASIC, 22

Text(0,0,"HELLO WORLD!

White background. Use TI-Connect if you wish to retrieve it from the calculator. Resulting PNG:

enter image description here

\$\endgroup\$
9
  • 8
    \$\begingroup\$ There's a PNG file on the calculator? \$\endgroup\$
    – skeevey
    Commented Feb 1, 2014 at 20:29
  • 22
    \$\begingroup\$ The calculator may have a 94 by 62 bitmap, stored in its own uncompressed format. I'll put my money on Ti-Connect converting it into a PNG when it's retrieved. \$\endgroup\$
    – Tobia
    Commented Feb 1, 2014 at 23:00
  • 18
    \$\begingroup\$ Can you post the resulting PNG? \$\endgroup\$ Commented Feb 2, 2014 at 5:44
  • 9
    \$\begingroup\$ This does not produce a .png image in the calculators memory. Retrieving it from the calculator converts it to a .png image. \$\endgroup\$
    – Rolf ツ
    Commented Feb 4, 2014 at 13:13
  • 12
    \$\begingroup\$ Personally, I think this is like displaying Hello world! on my computer screen and then saying "Oh, but I can easily convert it to a .png by taking a screenshot of it!" \$\endgroup\$ Commented Feb 7, 2014 at 1:12
8
\$\begingroup\$

BASH + RST + ImageMagick = 43 chars

Just for fun, here's another (quite ugly) one:

echo 'Hello World!'|rst2pdf|convert - a.png

Output:

Hello World!

\$\endgroup\$
6
\$\begingroup\$

Gnuplot

Not really a true competitor, just for fun. (homepage)

#!/usr/bin/gnuplot
set terminal pngcairo
set output "hw.png"
set label "Hello\nWorld!"
unset xtics
unset ytics
set yrange [-1:+1]
plot -1 notitle

or, as a oneliner (thanks to Phil H): 74 characters

se te pngc;se ou "q.png";se la "Hello world!";se yr[-1:1];uns ti;pl -1 not
\$\endgroup\$
2
  • 1
    \$\begingroup\$ You can shorten each of those commands to the minimum unique stub - so set te works, and set out etc. And you only need the top line to make it executable in the terminal, which is not a usual code golf requirement. So: se te pngc;se ou "q.png";se la "Hello world!";se yr[-1:1];uns ti;pl -1 not - 74 chars \$\endgroup\$
    – Phil H
    Commented Feb 4, 2014 at 16:31
  • \$\begingroup\$ @Phil H: yeah, sure, thanks ;-) Actually I knew commands could be shortened, but as this contrib wasn't really designed to compete with more efficient solutions, I thought I might as well show full length commands for educational purposes. \$\endgroup\$
    – kebs
    Commented Feb 5, 2014 at 18:59
5
\$\begingroup\$

Perl, 95:

The whole command incantation:

perl -MGD::Simple -e'$i=new GD::Simple;moveTo$i 9,50;string$i "Hello world!";print$i->png'>.png

Because of (reasonable) module defaults, it's 95 characters (or 92 if single letter file name allowed).

On Windows we need to binmode STDOUT, the shortest way I think can be -M-encoding+ get rid of double colons:

perl -MGD'Simple -M-encoding -e"$i=new GD'Simple;moveTo$i 9,50;string$i 'Hello world!';print$i->png">.png

i.e. 105

enter image description here

\$\endgroup\$
5
\$\begingroup\$

Data URI: 446

Following Chloe's idea, applied some basic optimisation to the image.

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAEEAAAALCAAAAAAFX7+TAAABBUlEQVQoz2P4Tylg+M8IohiRRUCIkC6E0sFlwhFBJo5kmPAdWSYmuTsgGa6y/3pMf/8yLYEJMcQwARXckmZi8YCawAAG//8L537ZxbEMaoKCwuvXCkogE2y0/nMyL1vC/BcmxKC6AqhAXurBc1kGkNUINzCBDIqFmsB84f//c8wgmcVs91j13d3U4EIMl0AKmM78/38GqJQXyQSWQ///H3sJMwGo7ALYhL/MQUq1wkK1cCEGsE+ZgSacAzKNkUxQ1/kygfEczBeKb18rKICDS4U58SUT8ye4EMQEBelHz+WAzEokE+6IM7HkI4ekLDgk/5cxnPrPK/4fLgQxARSSUdCQpBQAAFZKE8rQG60FAAAAAElFTkSuQmCC

Might be able to hack it further, but then would not be a perfectly conformant PNG and some viewers may not display it correctly.

\$\endgroup\$
10
  • \$\begingroup\$ Could you explain what kind of optimizations did you perform? \$\endgroup\$
    – svick
    Commented Feb 3, 2014 at 15:48
  • \$\begingroup\$ PNG2, stripped optional chunks, optimal (not streamed) compression \$\endgroup\$
    – OrangeDog
    Commented Feb 3, 2014 at 16:22
  • 1
    \$\begingroup\$ If you reduce the font size slightly, remove the spacing, the actual binary size of the image would be smaller than some of the posted solutions. \$\endgroup\$
    – OrangeDog
    Commented Feb 3, 2014 at 16:24
  • 1
    \$\begingroup\$ @OrangeDog I got it down to 179: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAC0AAAAHAQAAAAC0VvlnAAAAOklEQVR4nGLIv/57/+9rDGDqAkPOterN 0YIM3KG712pdZcgI3bW26gZD9lUwlRNWW1wtAAAAAP//AwCcyhjs3+7tWQAAAABJRU5ErkJggg== \$\endgroup\$
    – r3mainer
    Commented Feb 3, 2014 at 16:37
  • 1
    \$\begingroup\$ @squeamishossifrage That doesn't load in Firefox for me. \$\endgroup\$
    – OrangeDog
    Commented Feb 3, 2014 at 17:05
5
\$\begingroup\$

Python and Matplotlib - 66 65 chars

from pylab import*;title('Hello world!');axis('off');savefig('X')

Bit of whitespace, but it has the text and nothing else. File is saved as X.png:

enter image description here

\$\endgroup\$
3
  • \$\begingroup\$ from pylab import* \$\endgroup\$
    – Timtech
    Commented Feb 3, 2014 at 23:04
  • \$\begingroup\$ @Timtech thanks, I'm a golfing noob clearly ;) \$\endgroup\$
    – Nick T
    Commented Feb 4, 2014 at 0:36
  • \$\begingroup\$ I think you did a great job! \$\endgroup\$
    – Timtech
    Commented Feb 4, 2014 at 0:47
4
\$\begingroup\$

Ghostscript command line incantation, 84 (i.e. Postscript) :

 gs -sDEVICE=png16 -oa.png -c '/ 72 selectfont 9 9 moveto(Hello world!)show showpage'

Missing font message is intentional ;-). And proper (i.e. not hidden) name for our PNG file, too :-)

\$\endgroup\$
4
\$\begingroup\$

Python with PIL 122 Chars

from PIL import Image,ImageDraw;d=Image.new("RGB",(70,9));i=ImageDraw.Draw(d);i.text((0,0),"Hello World!");d.save("a.png")

It could probably be much smaller but I haven't worked with PIL extensively and made this in 5 minutes.

Output: enter image description here

\$\endgroup\$
4
  • 2
    \$\begingroup\$ You beat me to it by 10 minutes! With about 10 less chars! +1 :D Lose another char by going from 10 to 9 in your new, but you left out the !. \$\endgroup\$
    – Aaron Hall
    Commented Feb 2, 2014 at 1:29
  • \$\begingroup\$ The question state that it should have a white or transparent background. I myself think that the rules should be relaxed to allow black too, but for now, it fails the spec at this point. \$\endgroup\$ Commented Feb 2, 2014 at 5:26
  • 2
    \$\begingroup\$ Couldn't you save lots of characters with from PIL import*? \$\endgroup\$
    – Timtech
    Commented Feb 4, 2014 at 0:54
  • \$\begingroup\$ You would expect so, but you have to import them individually or else you get a not defined error from PIL import Image,ImageDraw;d=Image.new("RGB",(66,10));i=ImageDraw.Draw(d);i.text((0,0),"Hello World");d.save("a.png") NameError: name 'Image' is not defined \$\endgroup\$
    – globby
    Commented Feb 7, 2014 at 21:14
3
\$\begingroup\$

Bash + DOT, 46 41

dot -Tpng<<<'graph{label="Hello World!"}'

This outputs a png into the standard output. It is saving a file, but I don't think that was a requirement.

Outout: Hello World!

\$\endgroup\$
7
  • \$\begingroup\$ I we allow them be in ellipses, it can be 8 chars shorter... \$\endgroup\$
    – Bach
    Commented Feb 2, 2014 at 10:57
  • 1
    \$\begingroup\$ I am not sure whether you should add the bash chars as well for compiling this dot script. This adds dot -Tpng -op d, which is 15 chars. \$\endgroup\$
    – Bach
    Commented Feb 2, 2014 at 11:01
  • \$\begingroup\$ You should count the command line options/argument if they are needed to make your program solve the task. Normally the dashes are not counted, so I think you only should add Tnpg, op and d to the character count (+7), and specify how to run it in the answer itself. \$\endgroup\$
    – daniero
    Commented Feb 2, 2014 at 18:40
  • \$\begingroup\$ It can be better if you don't echo but instead write it in a file and run dot -Tpng on the file; it makes it 38, but I don't know if it counts... \$\endgroup\$
    – Bach
    Commented Feb 2, 2014 at 19:28
  • \$\begingroup\$ Why would it not count? \$\endgroup\$
    – daniero
    Commented Feb 2, 2014 at 20:13
3
\$\begingroup\$

Python, with 118 115 117 116 114 chars

Here's a full criteria passing with white text on alpha background at 116 114 chars!:

from PIL import Image,ImageDraw as D
m=Image.new("LA",(99,9))
D.Draw(m).text((9,0),'Hello World!')
m.save('r.png')

(You can replace newlines with semicolons - count is the same regardless.)

\$\endgroup\$
1
  • \$\begingroup\$ ImageDraw as D, and then D.Draw saves 3 chars. \$\endgroup\$
    – primo
    Commented Feb 2, 2014 at 3:02
2
\$\begingroup\$

PureBasic - 128 chars

UsePNGImageEncoder()
CreateImage(0,99,24)
StartDrawing(ImageOutput(0))
DrawText(0,0,"Hello World!")
SaveImage(0,"a.png",4673104)

enter image description here

Not the shortest here, but I have to support my favorite Basic language :)

edit: just in case there is a complain about the black background, at 133 chars:

UsePNGImageEncoder()
CreateImage(0,80,16)
StartDrawing(ImageOutput(0))
DrawText(0,0,"Hello World!",0,-1)
SaveImage(0,"a.png",4673104)

enter image description here

\$\endgroup\$
2
\$\begingroup\$

bash + netpbm: 31 chars

pbmtext "Hello world!"|pnmtopng

Will make:

Hello world by netPBM

\$\endgroup\$
2
\$\begingroup\$

Rebol/View 45

save/png %i to-image layout[h1"Hello World!"]  

writes a png image file named i into current directory

\$\endgroup\$
2
\$\begingroup\$

Internet 11

Internet is an API!

ow.ly/thgUJ -> http://dummyimage.com/99x9/f/0.png&text=Hello+world!

\$\endgroup\$
1

Not the answer you're looking for? Browse other questions tagged or ask your own question.