GD libary tutorials

[int3rface]

Just run the phpinfo on my account and it says I have the following:

GD Support: enabled
GD Version: 1.6.2 or higher
FreeType Support: enabled
FreeType Linkage with: TTF library
JPG Support: enabled
PNG Support: enabled
WBMP Support: enabled

WHat I wanted to know is can anyone recommend a good tutorial on creating an image gallery with on the fly thumbnails.

TIA

[Dr Livingston]

Umm....1) www.phpbuilder.com 2) www.devshed.com 3) www.wdvl.com and numerous other sites, though not all tutorials are of decent quality etc

[website]

/me slaps Dr Livingstone for not mentioning Sitepoint

http://www.sitepoint.com/article/937
Haven't read it though (shame on me I know...).

[website]

I would look at this http://www.phpbuilder.com/columns/in...at=2&subcat=17

[The Mog]

IMHO resizing images using the gd lib sucks unless you are using GD2+ then you can use 'imagecreatetruecolor'

the mog

[website]

IMHO resizing images using the gd lib sucks unless you are using GD2+ then you can use 'imagecreatetruecolor'

the mog

I must second that, the new ImageCreateTrueColor() and ImageCopyResampled() are essential, once you see the difference you will never go back! I tried this, had 2 scripts doing exactly the same, the newer one was just so much better then the other one...

Dr Livingston, yes it is definitely time to change!

[Dr Livingston]

Umm... Time I upgraded then ? Website - I'll slap you back remember

[The Mog]

And finally (20 min later) here is the code you would need

<?
  if ($mode == "small") {
    $thumbnailsize = 100;
  } else if ($mode == "medium") {
    $thumbnailsize = 160;
  } else if ($mode == "large") {
    $thumbnailsize = 350;
  }
  $path = "images/$file";
  $img = ImageCreateFromJPEG($path);
  $originalX = imagesx($img);
  $originalY = imagesy($img);
  if ($originalX > $originalY) {
    $sf = (double) $thumbnailsize / $originalX;
  } else {
    $sf = (double) $thumbnailsize / $originalY;
  }
  $neww = $originalX * $sf;
  $newh = $originalY * $sf;
  $tn = ImageCreateTrueColor($neww, $newh);
  ImageCopyResampled($tn, $img, 0,0,0,0, $neww, $newh, $originalX, $originalY);
  Header("Content-Type: image/jpeg");
  ImageJPEG($tn);
  ImageDestroy($tn);
  ImageDestroy($img);
?>

call this file something like resize.php and call your image as such
<img src="resize.php?file=imageName.jpg&mode=small">

The Mog

[int3rface]

cheers for that ;-)

[Jeff Lange]

It's all dependant on register_globals though

add:

$mode = $_REQUEST['mode'];
$file = $_REQUEST['file']; 

to the top of that.

[pootergeist]

that's a GD2+ scriptlet as it uses both imagecreatetruecolor and imagecopyresampled. If those functions will not work on your build, I'd suggest reading the sitepoint article linked above which teaches a trick for raising the palette indices from 256 to 16.7million and thus produces much better images.

If you do have GD2+ you may be interested in a thumbnailing class I also wrote which has a range of effects such as drop shadow, bevel, ellipse, overlay, greyscale etc - located at http://vextron.mirrors.phpclasses.or...kage/1007.html