Viewing Thread:
"I'm still having trouble with PHP image functions."

I've never been able to get these to work:

$img_file = "sourceimage.jpg";

header("Content-type: image/jpeg");
$width = 180;
list($width_orig, $height_orig) = getimagesize($img_file);
print("$width_orig, $height_orig

");
$height = (int) (($width / $width_orig) * $height_orig);

$image_p = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($img_file);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

imagejpeg($image_p, $img_file, 100);
imagedestroy($img_file);

Lifted mostly from PHP.net. Am I supposed to make this in a seperate file, then use it with HTML image tags? Had a look around the web, but couldn't find anything helpful. There's no apparent output, and my GD build is ok.

I shouted out about 6 months ago, more than once, then left it.

This has made my day though.

Ya shoulda shouted earlier - I've just made a gallery site using these exact functions. I'd have emailed you my code!

Help yourself mate, I got it mostly from php.net

Really bloomin' useful, wish I'd sorted it out sooner! (by that I mean "wish I'd got Garin to sort it out sooner")

You don't mind me lifting this code at some stage do you m_m. Obviously it wont be exactly the same but I need something similar for a gallery.

OK, cheers for the help Garin, I can't begin to tell you how many sites this is going to help me out on!

You, sire, are a genius.

EDIT: Yeah I did a quick test, uploaded a 0.5Mb file, thumbnailed it as a 27k file. Supoib.

monkey_man wrote:
> One more thing: I'm assuming that if I upload a large image, this
> technique is to dynamically create a thumbnail of small filesize? I
> know it's obvious, but just making sure it doesn't load the entire
> image first, then resize it...

Yes, the image resizing is being done on the server by PHP, which outputs a smaller image that the browser downloads.
If you're going to use this alot, you'd be advised to look at doing the resizing once and writing out file, rather than doing it on the fly everytime though.

EDIT: Aha - the header was in the wrong place, d'oh!

$img_dir = "../images/products/image_";
$img_format = ".jpg";
$img_file = "$img_dir$img_id$img_format";
$width = 180;

header("Content-type: image/jpeg");
list($width_orig, $height_orig) = getimagesize($img_file);
$height = (int) (($width / $width_orig) * $height_orig);

$image_p = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($img_file);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

imagejpeg($image_p, null, 100);
imagedestroy($image_p);

Super.

One more thing: I'm assuming that if I upload a large image, this technique is to dynamically create a thumbnail of small filesize? I know it's obvious, but just making sure it doesn't load the entire image first, then resize it...

Haha, ok. Still not working. Also, am I destroying the right image? Should that be image_p too?

EDIT: OK, this is what I have in the load_image.php file:


header("Content-type: image/jpeg");
$img_dir = "../images/products/image_";
$img_format = ".jpg";
$img_file = "$img_dir$img_id$img_format";
$width = 180;
list($width_orig, $height_orig) = getimagesize($img_file);
$height = (int) (($width / $width_orig) * $height_orig);

$image_p = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($img_file);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

imagejpeg($image_p, 100);
imagedestroy($image_p);

?>

What HTML do I need to put in? ?

monkey_man wrote:
> So I won't be able to set the quality?

You can if you like. :)

imagejeg($image_p,100);

Garin wrote:
> should be....
>
> imagejeg($image_p);

So I won't be able to set the quality?