Adding Text to an Image

Using the PHP GD function called imagecreatefromjpeg, imagecreatefromgif and imagecreatefrompng. We can add a custom text to an already existing image file.
So you have imagecreatefromjpeg for jpeg file, imagecreatefrompng for png file and so on.

< ?php
header("Content-type: image/png");
$string = "copyright: some text";
$font = 4;
$width = imagefontwidth($font)* strlen($string) ;
$height = imagefontheight($font) ;

This will setup the structure of the data being sent to the image file as well as what location to place the text at. In this case we want to place it on the bottom right of the page.

Now, we use imagecreatefrompng to create image from a file, set the text color, get the images dimensions, and figure on where to place the text.

$im = imagecreatefrompng("/path/to/yourimagefile");
$x = imagesx($im) - $width ;
$y = imagesy($im) - $height;
 
$backgroundColor = imagecolorallocate ($im, 255, 255, 255);   //white background
$textColor = imagecolorallocate ($im, 0, 0, 0);   //black text
imagestring ($im, $font, $x, $y,  $string, $textColor);

Finally we produce the new image that will display custom text in an image.

imagepng ($im);
?>

Here is the complete code:

< ?php
header ("Content-type: image/png");
$string = "your text";
// try changing this as well
$font = 4;
$width = imagefontwidth($font) * strlen($string) ;
$height = imagefontheight($font) ;
$im = imagecreatefrompng("/path/to/yourimagefile");
$x = imagesx($im) - $width ;
$y = imagesy($im) - $height;
$backgroundColor = imagecolorallocate ($im, 255, 255, 255);
$textColor = imagecolorallocate ($im, 0, 0,0);
imagestring ($im, $font, $x, $y,  $string, $textColor);
imagepng($im);
?>

You may like to view demo.

1. #1 by josh May 4th, 2008 at 8:07 am
   
   

   it didn’t work.. it only outputs the location of the php file but in image form.

2. #2 by bob the dangerous May 30th, 2008 at 8:37 pm
   
   

   You cannot place any rendering code in this file as it’s returning just an image file.

   No session_start, echo or just plain HTML.