vb.org Archive - generating real thumbnails on the fly

vb.org Archive (https://vborg.vbsupport.ru/index.php)

- vB3 Programming Discussions (https://vborg.vbsupport.ru/forumdisplay.php?f=15)

- - generating real thumbnails on the fly (https://vborg.vbsupport.ru/showthread.php?t=58861)

matthew tucker

11-28-2003 04:41 AM

generating real thumbnails on the fly

Has anyone worked out how to generate a real resized image thumbnail on the fly using PHP and the GD library? I can't find a hack for it.

In other words, not just displaying the image in a resized <img> tage, but displaying a real re-sized image?

I can do it from an image FILE read directly from an images folder, but I can't work out how to pass the data from $attachment(filedata) to the ImageCreateFromJPEG ($imgfile) function. Just replacing $imgfile with $attachment(filedata) doesn't work of course.

The top image in the left hand column at the following website is done from a file in a folder.
http://www.screeneditors.com/forums/index.php

the other images in the left hand column are just resized. Modem users complaining a bit ...

is there a better way than saving the imagedata in a temp file then processing it?

NTLDR

11-28-2003 03:01 PM

You need to specify a filename and path, passing the data won't work. You can use the URL to the attachment and pass that:

PHP Code:


		
			
imagecreatefromjpeg('hhtp://www.mysite.com/forums/attachment.php?attachmentid=2');

Something similar to the above should work.

matthew tucker

11-29-2003 08:33 PM

Thank you Lee

But most of my images are in the MYSQL attachments database.

How can I do the above transformation on them *without* exporting them to disk as files??

I'm think about installing the "attachments as files" hack but I don't want to unless I really need to.

(Botley? I was brought up in Botley, Oxford! first time I've seen that name in 20 years!)

filburt1

11-29-2003 08:37 PM

Quote:

Originally Posted by matthew tucker

Look at (IIRC) imagecreatefromstring: http://www.php.net/imagecreatefromstring

matthew tucker

11-30-2003 08:13 AM

imagecreatefromstring() does it!

thanks for that pointer.

but it seems REALLY slow ... is this normal? I mean, it seems slower than just loading the whole image!

using basic code from PHP.net ...

PHP Code:


		
			
 header('Content-type: image/jpeg');
$data = $attachmentinfo[filedata];
$size = 150; 
$src = imagecreatefromstring ($data);
$width = imagesx($src);
$height = imagesy($src);
$aspect_ratio = $height/$width; 
 
if ($height <= $size) {
$new_w = $width;
$new_h = $height;
} else {
$new_h = $size;
$new_w = abs($new_h / $aspect_ratio);
}
 
$img = imagecreatetruecolor ($new_w,$new_h); 
 
imagecopyresampled ($img,$src,0,0,0,0,$new_w,$new_h,$width,$height); 
 
// or imagecopyresized()
 
imagejpeg($img ); //,'', 90

matthew tucker

11-30-2003 08:49 AM

OK yep, its normal. Just read up a bit more on PHP.net.

So ... I think from now on I'll be generating thumbs on upload and store in database...

All times are GMT. The time now is 10:49 AM.

X vBulletin 3.8.12 by vBS Debug Information
Page Generation 0.00973 seconds Memory Usage 1,735KB Queries Executed 10 (?)
More Information
Template Usage: (1)ad_footer_end (1)ad_footer_start (1)ad_header_end (1)ad_header_logo (1)ad_navbar_below (2)bbcode_php_printable (1)bbcode_quote_printable (1)footer (1)gobutton (1)header (1)headinclude (6)option (1)post_thanks_navbar_search (1)printthread (6)printthreadbit (1)spacer_close (1)spacer_open Phrase Groups Available: global postbit showthread	Included Files: ./printthread.php ./global.php ./includes/init.php ./includes/class_core.php ./includes/config.php ./includes/functions.php ./includes/class_hook.php ./includes/modsystem_functions.php ./includes/class_bbcode_alt.php ./includes/class_bbcode.php ./includes/functions_bigthree.php Hooks Called: init_startup init_startup_session_setup_start init_startup_session_setup_complete cache_permissions fetch_threadinfo_query fetch_threadinfo fetch_foruminfo style_fetch cache_templates global_start parse_templates global_setup_complete printthread_start bbcode_fetch_tags bbcode_create bbcode_parse_start bbcode_parse_complete_precache bbcode_parse_complete printthread_post printthread_complete
Messages: