image resize

neljan

Hello

I have a .php and an .html file. The php file is pulling an image from somewhere (sorry to be technical :p) and the html file is then displaying it via a string (I believe). Can someone please tell me how I change the size of the displayed image (create a thumbnail if you like).

Heres my php:

if($ds['userpic']) $userpic = '<img src="images/userpics/'.$ds['userpic'].'" alt="" />';
else $userpic = '<img src="images/userpics/nouserpic.gif" alt="" />';

And the HTML:

<td class="picture" height="100" align="left">$userpic</td>

Thanks in advance for any advice.

😃

Krik

Use [man]getimagesize[/man] and then do a bit of math and insert the new sizes into the <img> tag.

neljan

I'm a total php noob and have no idea what I'm looking at there tbh.

Krik

Here is piece of code I used a few months ago.

$imagesize = getimagesize('yourpic.jpg');

if ($imagesize[0] > '200') {

	$widthfraction = ('200' / $imagesize[0]);

	$imagewidth = round($widthfrac * $imagesize[0]);
	$imageheight = round($widthfrac * $imagesize[1]);
}

NogDog

Just a side note: if you "re-size" an image simply by setting width/height attribute values in the HTML <img> tag, you still transmit the full-sized image file to the browser; so it only gets re-sized once it's received by the browser. The alternative to avoid transferring the full-size image is to do the resizing on the server, either creating separate thumbnail image files when the file is uploaded, or re-sizing "on the fly" each time the image is requested via an "image server" script (see [man]imagecopyresampled/man).

neljan

The picture(s) I am trying to resize is/are uploaded by the user, so I dont have a specific designated image url.

Krik

Even for a user uploaded file you have to designate the folder it will be uploaded to and you have to designate the name. Now whether you use the name of the file that the user had on it or you have some other system for naming them your code has to very intentional specify the files name before it can be uploaded.

You may need to do some research on uploading files, http://php.net/manual/en/features.file-upload.post-method.php

johanafm

NogDog;10958370 wrote:
The alternative to avoid transferring the full-size image is to do the resizing on the server, either creating separate thumbnail image files when the file is uploaded, or re-sizing "on the fly" each time the image is requested via an "image server" script (see [man]imagecopyresampled/man).

Or resize "on the fly" once, i.e. the first time this specific image size is requested.