Write a text on an image

Here is the next part of the tutorial to include text in images. To understand this, you must have read the basics on images in PHP with GD2.

Images in PHP with GD2 - Part 2 put some text on the image

The text

The basic function to add a text is imagestring which is used with imageloadfont to indicate the write font. But using these functions is less simple and portable than imagettftext which allows to load a TTF format font. So I will only talk about this last.
imagettftext (resource $image, float $size, float $angle, int $x, int $y, int $color, string $ttf_file, string $text)

$size is the font size in points, $angle is the angle in degree, $ttf_file is the font file to use. So just put this font with the rest of the site to see your script run on any server.

Okay, now we have all the elements to set the text in a empty image. I will put everything as parameter, so you can have fun. This is the HTML code that inserts my image:
<img src="http://azure.ironie.org/fichiers/texte-image.php?l=350&h=100&texte1=azure.ironie.org&texte2=This text is modifiable!&couleur1=FFFFFF&couleur2=AADD44&couleur_fond=1F1F1F" alt="text in image" />


It gives:

Here's the link to the image, try to modify the text and the colors, you will immediately see the useful aspect for the title in images.

Keep in mind that this text won't have the SEO power of a text, but of an image! We can't have everything.

And here's finally the PHP code generating this little wonder.


<?php
/**
 * Text in image - azure.ironie.org
 * The variables to give are: l h texte1 texte2 couleur_texte1 couleur_texte2 couleur_fond
 * = width height text1 text2 text1_color text2_color background_color
 */
 
header ('Content-type: image/png');
 
$im = imagecreate ($_GET['l'], $_GET['h']);
// or $im = imagecreatetruecolor ($_GET['l'], $_GET['h']);
 
$couleur_fond = imagecolorallocate ($im,
   hexdec(substr($_GET['couleur_fond'], 0, 2)),
   hexdec(substr($_GET['couleur_fond'], 2, 2)),
   hexdec(substr($_GET['couleur_fond'], 4, 2)));
 
// and if we choose imagecreatetruecolor, add the background with:
// imagefilledrectangle($im, 0, 0, $_GET['l'], $_GET['h'], $couleur_fond);
 
$couleur1 = imagecolorallocate ($im,
   hexdec(substr($_GET['couleur1'], 0, 2)),
   hexdec(substr($_GET['couleur1'], 2, 2)),
   hexdec(substr($_GET['couleur1'], 4, 2)));
$couleur2 = imagecolorallocate ($im,
   hexdec(substr($_GET['couleur2'], 0, 2)),
   hexdec(substr($_GET['couleur2'], 2, 2)),
   hexdec(substr($_GET['couleur2'], 4, 2)));
 
imagettftext ($im, 18, 10, 30, 45, $couleur1, './desyrel.ttf', stripslashes ($_GET['texte1']));
imagettftext ($im, 24, 0, 15, 65, $couleur2, './desyrel.ttf', stripslashes ($_GET['texte2']));
// Retire stripslashes if magic_quotes is disabled.
 
imagepng($im);
imagedestroy($im);
 
?>

The .ttf file requires of course, to be the the .php file.

Finally I would remind you that the texts and codes on this site are protected by copyright. The goal is that you learn and not copy-paste my PHP code.

On occasion I will continue with the shapes drawing and modification of existing images or pictures. I will also talk about the error handling missing in this example.

This article was posted by David
the Monday 1 September 2008 at 22:12
in the category Graphism, PHP with tags: Graphism, PHP, Programming. You can leave an answer, or backlink from your own website.