Screen capture with PHP and GD
Posted by Pierre in
Uncategorized
Tuesday, April 17. 2007
To get a snapshot of a HTML page, a window or a complete screen was always something tricky to do in PHP. For one of my current projects, I had to check that our changes did not affect visually any page. An easy way to achieve this goal is to compare the rendered pages in the browsers itself, easy and time consuming (for a human being 
).
That’s why I finally sit down and implemented imagegrabscreen and imagegrabwindow . They capture respectively the whole screen or a window (using its handle).
Thanks to Edin Kadribaši?, you can fetch a 5.2.x (Threadsage build only) DLL here, simply replace the php_gd2.dll by this one (it is what will be in 5.2.2).
- Screenshot
<?php $im = imagegrabscreen(); imagepng($im,“myscreenshot.png”); ?>
- Capture a window (IE for example)
<br /> <?php <br /> $browser = new <acronym title="“InternetExplorer.Application”">COM</acronym>;<br /> $handle = $browser->HWND;<br /> $browser->Visible = true;<br /> $im = imagegrabwindow($handle);<br /> $browser->Quit(); imagepng($im, “iesnap.png”);<br /> $im = imagegrabscreen(); <br /> ?><br />
- Capture a window (IE for example) but with its content!
<?php $browser = new <acronym title="“InternetExplorer.Application”">COM</acronym>; $handle = $browser->HWND; $browser->Visible = true; $browser->Navigate(“http://blog.thepimp.net”); /* Still working? */ while ($browser->Busy) { com_message_pump(4000); } $im = imagegrabwindow($handle, 0); $browser->Quit(); imagepng($im, “iesnap.png”); ?>
- IE in fullscreen mode
$browser = new <acronym title="“InternetExplorer.Application”">COM</acronym>; $handle = $browser->HWND; $browser->Visible = true; $browser->FullScreen = true; $browser->Navigate(“http://blog.thepimp.net”); /* Still working? */ while ($browser->Busy) { com_message_pump(4000); } $im = imagegrabwindow($handle, 0); $browser->Quit(); imagepng($im, “iesnap.png”); ?>
I use Internet Explorer as example, if you like to play more with IE and com, check out the IBrowser2 documentation at MSDN. It should work with any kind of window as long as you give the correct handle (usually $obj->HWND).
- php_gd2.dll for 5.2.x thread safe build
- php gd image documentation
- IE manual (useful to tweak it from com_dotnet
Pierre - #4 - 2007-04-18 09:56 - (Reply)
Byron:&quot;Thanks Pierre! I've always wondered how to go about this....&quot; Same here Markus:"Any examples of doing this with FF too? Does FF provide COM object" No idea. If not it is maybe possible using some custom .net code. Please leave a comment if you find a solution 
@Marco "I just get black png files. Whats wrong?" Code?
Pierre - #12 - 2007-04-19 16:41 - (Reply)
Bill911 In what this product (49$ per user) has anything to do with automatic screen captures from PHP? It is even not possible to use from a script. Is it me or this comment smells like an Ad? Hamish Thanks, fixed.
Pierre - #14 - 2007-04-20 13:19 - (Reply)
@jca0811 It should be possible to do it using the Document property. See:
http://msdn.microsoft.com/workshop/... Let us know how it works out
Pierre - #21 - 2007-05-13 09:55 - (Reply)
Hi Silvano! IRC on freenode or per email are two ways to reach me
Rob - #26.1.1 - 2008-03-27 21:07 - (Reply)
I think I miscommunicated a little, I implemented it on a page (on my webserver) and opened the php file in the browser of another system, but the screenshot it drops is of the server. I got it working, and will probably use this server side screen capturing in other apps, but at the moment I’m looking for a way to get the client’s screenshot without them having to do anything (users get confused easily )
How would I go about creating a desklet application? How is it different then the standard php files I run from my server? I’d like to learn more about this sort of functionality, do you have any resources I could read through?
Rob - #27.1.1 - 2008-04-01 15:04 - (Reply)
I really only need the browser window. But I don’t think I’ll be able to do this without more work then its worth, I’ll just stick with the old trusty ‘Print Screen’ button. Thanks for all the help Pierre, your work on these pages is inspiring
Sascha - #31 - 2008-05-14 16:17 - (Reply)
Hi Pierre,
imagegrabscreen() is a great addon to PHP, but somehow I can’t use it with my current webserver configuration and that’s why I would like to ask for your support:
I first created a threeliner to grab a screenshot and save it to disk; I called it directly via cli and it worked like a charm.
Being convinced that the script would also work from within my webserver, I altered one of my monitoring scripts to grab the screen, save it and show the image on a web page, but all I got was a white (not black like mentioned in other posts) image!
function os_show_screen (){ $im = imagegrabscreen(); unlink(‘temp/screen.png’); imagepng($im, ‘temp/screen.png’); print ‘&lt;img src=\‘temp/screen.png?’.time().’\’&gt;";<br /> }
I checked that both IIS and the WWW Publishingservice were allowed to interact with the desktop, but that didn’t help.
My current setup is as follows:
Windows 2000 Server, IIS 5 with ZendCore for Oracle running PHP as FastCGI
Do you have a clue what would cause this behaviour?
Thanks a lot (also for the great contribution)!!
P.S. The code is a bit messed up but I hope you’ll still see how the script works.
P.P.S. The code highlighter should end with [/geshi] instead of [/lang] 
Sascha - #31.1.2 - 2008-05-16 09:51 - (Reply)
Additional comment:
I was wrong when I said that the CLI script call created a screenshot – I copied my local files to the remote machine, called the script and the file seemed to be created; instead it hadn’t been overwritten because of access restrictions … as a result, imagegrabscreen() never worked on my windows 2000 server 
