Small Tutorial on GD Library

[mr e]

This is just something small I threw together to help those people who couldn't figure out how to use this gd library thing

I did this on a home server so that's how I'm gonna explain it, otherwise just ask your host to add the gd library.

I did this on Win XP, and I followed TECK's tutorial for installing PHP, Apache, and MySQL.

1) Install/Upgrade to PHP v4.3.2 (RC1 or whatever), I have 4.3.2 RC1


2) Open php.ini and find this line

;extension_dir =

or something like that, uncomment it and change it to the directory you have your extensions in, for me it was

extension_dir = "c:\network\php\extensions"


3) Still in php.ini find this line

;extension=php_gd2.dll

and uncomment it


4) Restart Apache


I assume most of you will just want to add text to a picture so this is how to do it.

Using a .jpg

1) Create a file with this in it

PHP Code:

<?
Header("Content-Type: image/jpeg");

$img = ImageCreateFromJpeg("LOCATIONOFIMAGE"); // eg: images/test.jpg or test.jpg

$color = ImageColorClosest($img, 255, 255, 255); // image, rrr, ggg, bbb 

ImageString($img, FONTNUMBER, DISTANCEFROMLEFT, DISTANCEFROMTOP, "TEXTTODISPLAY", $color); // the distance is in pixels and the font # is 1 through 5

ImageJpeg($img); // make the image

ImageDestroy($img); // get the image out of memory
?>

Using a .png

1) Create a file with this in it

PHP Code:

<?
Header("Content-Type: image/png");

$img = ImageCreateFromPng("LOCATIONOFIMAGE"); // eg: images/test.png or test.png


//a png uses ImageColorAllocate instead of ImageColorClosest like jpeg ueses
$color = ImageColorAllocate($img, 255, 255, 255); // image, rrr, ggg, bbb

ImageString($img, FONTNUMBER, DISTANCEFROMLEFT, DISTANCEFROMTOP, "TEXTTODISPLAY", $color); // the distance is in pixels and the font # is 1 through 5

ImagePng($img); // make the image

ImageDestroy($img); // get the image out of memory
?>

Note: If you wanted to have say...forum stats in this then you would query the stats and then instead of

PHP Code:

ImageJpeg($img);
//or
ImagePng($img);

//you would do

ImageJpeg($img, 'FILENAMETOOUTPUT', 100); // last number is the quality
//or
ImagePng($img, 'FILENAMETOOUTPUT'); 


then you would just do a regulare <img> tag with the image pointing to the FILENAMETOOUTPUT, then do a cron job (i have NO idea how to do [sorry]) to run that script every so often.

For searching purposes: graphic development library