Entries tagged as GD
King thief
Posted by Pierre in
Uncategorized
Thursday, December 6. 2007
These guys rock:
I discover them while checking a nice little package on freshmeat. If you are in the St-Louis area and have the chance to see them live, go!
About the little php package, it is a nice antialiased circular arc implementation, if you ever need rounded corners 
ps: yes, that’s coming in the extension as well, s…ooon
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
imagerotate, little confusions in the manual (damned, I cannot say RTFM!)
Posted by Pierre in
Uncategorized
Tuesday, February 6. 2007
imagerotate has special intern functions when the rotation angle is a multiple of 90°, it actually only flips the image. The operation is quite fast as it is a two nested loops with a little copy operation. However it looks like the manual has a little mistake in the function description, which can lead to confusion:
"The center of rotation is the center of the image, and the rotated image is scaled down so that the whole rotated image fits in the destination image – the edges are not clipped."
<br /> $im = imagecreatefrompng(“foo.png”); <br /> imagepng($im, “2.png”);<br /> $imr = imagerotate($im, 90, 1, 1);<br /> imagepng($imr, “foo_90.png”);<br /> $imr = imagerotate($im, 180, 1, 1);<br /> imagepng($imr, “foo_180.png”); <br /> $imr = imagerotate($im, 270, 1, 1);<br /> imagepng($imr, “foo_270.png”); <br /> $imr = imagerotate($im, 30, 0×000FF, 0);<br /> imagepng($imr, “foo_30.png”);<br />
Will return: 
As you can see, as long as the rotation is only a flip (angle is a multiple of 90°), the image dimensions are preserved. If not, the final image will have the exact size required by the rotated image. I hope it is clearer now, I will try to update the manual as soon as possible. Thanks to the phpdoc team, I can now put all kind of psychedelic images in there!
phpgd.com
Posted by Pierre in
PHP
Thursday, March 16. 2006
In his news section, Dams introduces the “new” phpGD website, a site dedicated to PHP and GD. I have not heard about it until now and I am nicely surprised about this initiative.
There is a couple of nice scripts, and your contributions are welcome.
I will hang around the forums, it could be a niceway to get more feedbacks (good or bad :-), even if I try to focus on my vapourware
See you there!
imagepng, take #2
Posted by Pierre in
PHP
Friday, January 27. 2006
Bernhard Seefeld was testing the new compression option for imagepng and was wondering why there is still a relative big difference in image sizes.
In my first attempt to create smaller images, I only allowed to change the compression, it was not sufficient to get really lite pictures.
After a short look to the libpng codebase (and the horrible imagick doc), I added a last argument to imagepng, the filtering mode. Here are the results, sorted by size (a.png is the source image):
<br /> 18650 a.png<br />
<br /> 18556 none.png<br /> 18556 all.png<br /> 24536 sub.png<br /> 28727 up.png<br /> 29095 paeth.png<br /> 32788 default.png<br /> 36658 avg.png<br />
I used this little script, if you like to test it:
<br /> <?php<br /> $im = imagecreatefrompng(“a.png”);<br /> imagesavealpha($im,true);<br /> imagepng($im, “default.png”, 9);<br /> imagepng($im, “none.png”, 9, PNG_NO_FILTER);<br /> imagepng($im, “sub.png”, 9, PNG_FILTER_SUB);<br /> imagepng($im, “up.png”, 9, PNG_FILTER_UP);<br /> imagepng($im, “avg.png”, 9, PNG_FILTER_AVG);<br /> imagepng($im, “paeth.png”, 9, PNG_FILTER_PAETH);<br /> imagepng($im, “all.png”, 9, PNG_ALL_FILTER);<br /> ?><br />
I save the alpha channel as the source image has a transparent “background”, but it is not really relevant here
The option will be present from PHP 5.1.3 (or whatever will be the next 5.x release) have fun while saving your bandwidth
What's new in GD, 5.1.x
Posted by Pierre in
PHP
Friday, December 9. 2005
I brought image convolutions to the public in PHP 5.1.0 (was lying in cvs for some months already), using a 3×3 matrix, the factor and the offset. A lot of really usefull or nice effects can be realized using image convolutions. I will show you some here.
The second introduction will be available in 5.1.2, it is nothing really new and I was even sure it was already done :P, thanks to Christian Stocker to remind me how wrong I was
Continue Reading What's new in GD, 5.1.x
