Image sizes in PHP

Napalm Llama · 07-13-2005, 07:44 AM

Hello there. I need a method of finding out how large (memory-wise) an image is - it doesn't mastter when this is found out (ie. before or after the image is sent), but the size does need to be recorded in a MySQL database.

Anybody know how to do this?

Cheers.

keefaz · 07-13-2005, 07:52 AM

I assume the image is uploaded as you said :
"(ie. before or after the image is sent)"

Say you named the upload field 'image' in your form,
then you could get the size as :

PHP Code:



$size = filesize($_FILES['image']['tmp_name']);

Nylex · 07-13-2005, 07:54 AM

You could use the filesize() function to do that. Read this.

Edit: damn it, too slow.

Napalm Llama · 07-13-2005, 11:17 AM

No, it isn't uploaded - that'd be the easy way

It's an image proxy, to measure how much bandwidth is being used, and only send a small placeholder image after 200mb.

A code fragment is:

PHP Code:



case "jpg": 
        $orig = imagecreatefromjpeg( $imgurl ); 
        header('Content-type: image/jpeg'); 
        imagejpeg($orig); 
        break;

It loads the image resource directly from the site. It has to do this due to oddities in my hosting, where I only get a tiny amount of 'smart' CGI-enabled space and a huge amount of 'dumb' space for keeping images and the like.

I could have it download the image to a temporary file, but this way is much more efficient - if I can measure the image's size. It is in memory, after all - surely there's a way of finding out how much it's using?

The result has to be stored in a MySQL database. (I guess it could be stored in a file instead, but I don't really see the point...)

vharishankar · 07-13-2005, 09:07 PM

What about the getimagesize() function?

Napalm Llama · 07-14-2005, 09:55 AM

No, I looked at that - as far as I can tell, it takes the path to a saved file as input and gives you it's physical sizes (ie. width x height) rather than its data size.

I've decided to do it the inefficient way now - it saves the file to disk using the copy() function, then gets its size before loading it in as an image.

Thanks for all your help though, it's greatly appreciated.

Hmm, would this constitute a possible feature request?

keefaz · 07-14-2005, 12:44 PM

You could get the size from the gd resource with something like :

PHP Code:



... 
$orig = imagecreatefromjpeg( $imgurl ); 
header('Content-type: image/jpeg'); 
ob_start(); 
imagejpeg($orig); 
$image_string = ob_get_contents(); 
$image_size = strlen($image_string);

then in $image_size, you should have the image size in bytes

Napalm Llama · 07-15-2005, 10:01 AM

Thanks, but I've realised that the way I've used is actually better now.

It measures the exact filesize transferred from the storage space, which is what I need to know - if the script re-encodes the image itself, its ouput might be a different length.

Thanks for the method, though - I'll refer back to this next time I'm confronted with a similar problem!