Resizing images with NETPBM

epp_b

I need to copy and resize an image to be a thumbnail. The server that I'm using my PHP on has a tool called NETPBM which can execute server side image editing. In this case, I'm trying to edit a JPEG image. This code works about half-way:

<?php
$image = "images/pic.jpg";
$thumb = "images/pic_small.jpg";
$binpath = "/path/to/netpbm/";

exec($binpath . "jpegtopnm " . $image . " | " . $binpath . "pnmscale - xysize 200 135 | " . $binpath . "pnmtojpeg -quality=75 > " . $thumb);
?>

What it does is: it will copy the image, rename the copied image appropriately ("pic_small.jpg"), but there will be no binary data in the image (size: 0kb; shows up as the little X-in-the-box when viewing in IE). Official Docs: http://netpbm.sourceforge.net/doc/. I've looked over the docs, still am, can't quite figure out what's wrong.

Anybody know something about this?

Royce

I use this script to create thumbnail images on the fly:

<?php

//where are the images?
$jpegdir = '';
$jpeg = $jpegdir .''. $HTTP_GET_VARS['img'];
$width=$HTTP_GET_VARS['width'];
$height=$HTTP_GET_VARS['height'];

if($d=getimagesize($jpeg)){
header('Content-type: image/jpeg');
$src = imagecreatefromjpeg($jpeg);
$dst = imagecreate($width,$height);
imagecopyresized($dst,$src,0,0,0,0,$width,$height,$d[0],$d[1]);
imagejpeg($dst);
imagedestroy($dst);
imagedestroy($src);
}

Your image source would look like <img src="http://www.yoursite.com/imageresizer.php?img=yourimage.jpg&width=160&height=120

Here's a real example from my site
http://www.mthigh.com/livecams/thumbmkr.php?img=topeast.jpg&width=195&height=146

I hope that maybe helps you.

epp_b

Hmmm...very interesting. It's a very different approach than what I was thinking of doing. I'll see if and how I can use this script. Very neat -- thanks 🙂

...Sorry, I can't really use this, because the images need to be created statically, not dynamically. So.....anybody familiar with NETPBM?

Umrath

actualy, his way can work.

just add the second parameter to imagejpeg

imagejpeg($im, "/web/user/public_html/staticimagename.jpg", 100);

the 3rd parameter is the quality of the jpeg.

epp_b

Actually, I finally got NETPBM working -- and it works quite nicely too 🙂

Umrath

perhaps you can help me, then.
http://www.phpbuilder.com/board/showthread.php?s=&threadid=10220891

epp_b

Be glad to 🙂

$binpath = "/path/to/netpbm/binaries/";
$original = "originalimage.jpg";
$final = "finalimage.jpg";

// convert to ppm
exec($binpath . "jpegtopnm $original > tmp.ppm");

// resize with only xscale (it will keep the aspect ratio)
exec($binpath . "pnmscale -xsize 100 $tmp1 > tmp2.ppm");

// convert ppm image to final jpeg image
exec($binpath . "ppmtojpeg $tmp2 > $final");

see http://netpbm.sourceforge.net/doc for more info on NETPBM.

Umrath

While I thank you, I think you're missing the idea... I want to find a way to execute netpbm or imagemagick without execution functions.
I'm pretty sure it's impossible, so is it psosible to set up a server where the exec() function only works on certain directories, i.e. the netpbm binaries.