PHP: imagegif - Manual

Description

bool imagegif ( resource image [, string filename] )

imagegif() creates the GIF file in filename from the image image. The image argument is the return from the imagecreatetruecolor() function.

The image format will be GIF87a unless the image has been made transparent with imagecolortransparent(), in which case the image format will be GIF89a.

The filename argument is optional, and if left off, the raw image stream will be output directly. By sending an image/gif content-type using header(), you can create a PHP script that outputs GIF images directly.

Замечание: Since all GIF support was removed from the GD library in version 1.6, this function is not available if you are using that version of the GD library. Support is expected to return in a version subsequent to the rerelease of GIF support in the GD library in mid 2004. For more information, see the GD Project site.
The following code snippet allows you to write more portable PHP applications by auto-detecting the type of GD support which is available. Replace the sequence header ("Content-type: image/gif"); imagegif ($im); by the more flexible sequence:

<?php if (function_exists("imagegif")) { header("Content-type: image/gif"); imagegif($im); } elseif (function_exists("imagejpeg")) { header("Content-type: image/jpeg"); imagejpeg($im, "", 0.5); } elseif (function_exists("imagepng")) { header("Content-type: image/png"); imagepng($im); } elseif (function_exists("imagewbmp")) { header("Content-type: image/vnd.wap.wbmp"); imagewbmp($im); } else { die("No image support in this PHP server"); } ?>

Замечание: As of version 3.0.18 and 4.0.2 you can use the function imagetypes() in place of function_exists() for checking the presence of the various supported image formats:

<?php if (imagetypes() & IMG_GIF) { header ("Content-type: image/gif"); imagegif ($im); } elseif (imagetypes() & IMG_JPG) { /* ... etc. */ } ?>

imagegif

rokfaith at gmail dot com
06-Jul-2006 03:34


to create an animated gif with gifsicle, but without storing temporary images on disk:

<?

$cmd = 'gifsicle --loop -O1 --multifile --delay 25 - > '.$outfile;

$desc = array(0 => array("pipe", "r"),1 => array("pipe", "w"),2 => array("pipe", "w"));

$proc = proc_open($cmd, $desc, $pipes);

if (!is_resource($proc)) {

  die('Unable to start gifsicle');

}

for ($frame=0; $frame<$total_frames; $frame++) {

  $image = RenderFrame($frame);

  ob_start();

  imagegif($image);

  fwrite($pipes[0], ob_get_contents());

  ob_end_clean();

  imagedestroy($image);

}

fclose($pipes[0]);

fclose($pipes[1]);

fclose($pipes[2]);

proc_close($proc);

?>



just define $outfile and RenderFrame(), and that's it.

joconoco at yahoo dot com
03-Feb-2006 05:12


i havent worked with it, yet. but for the discussion about animated gifs, this might help, too:

http://ffmpeg-php.sourceforge.net/apidoc.php

fieldy
31-Jan-2006 03:54


For using the new animated gif functions of gd you can build in some functions in php. I took the patch from http://hyvatti.iki.fi/~jaakko/sw/. But it's a patch on php 5.0.2. I made it on php 5.1.2.

On http://www.linuxforhomies.be/view_artikel.jsp?id=10 you can see how to do it. Sorry that it's in dutch, but I think it's understandable. 



It adds following functions:

int imagegifanimbegin(int im [, string filename [, int GlobalColormap [, int Loops]]]);

int imagegifanimadd(int im [, string filename [, int LocalColormap [, LeftOfs [, int TopOfs [, int Delay [, int Disposal [, int previm]]]]]]]);

int imagegifanimend([string filename]);

cascade at mylifesucks dot de
29-Nov-2005 04:02


I would rather use gifsicle ( http://www.lcdf.org/gifsicle/ ) instead of convert. It runs much faster with big animations. I got large animations with over 500 frames rendered where convert was killed by my system because of memory consumption. And it contains pretty well optimization.



A sample gifsicle usage (not much optimized):

<?

// Sample gifsicle usage to create a scrolling text



$gifsicle = "/usr/local/bin/gifsicle"; # http://www.lcdf.org/gifsicle/

$time = time();

for ($rend_frame = 0; $rend_frame <= 26; $rend_frame++) {

    $im = @imagecreatetruecolor(300, 20);

    $background = imagecolorallocate($im, 0, 0, 100);

    $red = imagecolorallocate($im, 255, 0, 0);

    $filename = "/tmp/giftest_".$time."_".str_pad($rend_frame, 10, "0", STR_PAD_LEFT).".gif";

    $framefiles[] = $filename;

    imagestring($im, 3, ($rend_frame * 15)-80, 3, "Animation rox", $red);

    imagegif($im,$filename);

    imagedestroy($im);

};

$outfile = "/tmp/giftest_".$time.".gif";

$cmd = "$gifsicle --loop -O1 --delay 25 /tmp/giftest_".$time."*> $outfile";

exec($cmd, $out, $err);

foreach ($framefiles as $framefile) {

    if (file_exists($framefile)) unlink($framefile);

};

header('Content-type: image/gif');

header('Content-Transfer-Encoding: binary');

header('Content-Disposition: inline; filename=test.gif');

header('Content-Length: '.@filesize($outfile));

readfile($outfile);

unlink($outfile);

?>



Or get patches from http://hyvatti.iki.fi/~jaakko/sw/ to be able to do it all inside php...

Leigh Purdie
03-Jul-2005 05:17


Simple animated-gif hack (requires ImageMagick):



<html><body>

<?php

        $icount=0;

        for($count=0;$count<40;$count++) {

                $im=imagecreate(200,200);

                imagecolorallocate($im,0,0,255);

                $white=imagecolorallocate($im,255,255,255);

                imagerectangle($im,$count,$count,200-$count,200-$count,$white);

                $icount++;

                $tcount=sprintf("%04d",$icount);

                imagegif($im,"/tmp/test-$tcount.gif");

                imagedestroy($im);

        }

        exec("/usr/bin/convert -delay 2 -loop 10 /tmp/test*.gif /var/www/html/Tests/Test-Anim.gif");

?>

<img src="/Tests/Test-Anim.gif">

</body>

</html>

Lauri Harpf
23-Jun-2005 09:25


Using <IMG SRC="image.php"> to dynamically generate images is a bit problematic regarding cache. Unless caching is activated, IE seems to get confused about the type of the image when attempting to save it. A .GIF created in the above way causes the browser to suggest saving the image with .BMP, not .GIF.



A solution is to activate cache with session_cache_limiter('public'); in "image.php", after which IE will correctly save as .GIF. If you do not want the cache to block any changes in the dynamic image, make sure that the SRC keeps changing with every reload. Something like "image.php/" . mt_rand(1,100000) . ".gif" seems to work well.



Might be trivial to some, but I spent a couple of hours figuring out why IE always wants to save my dynamic .GIF's as .BMP's.

jemore at nospam dot m6net dot fr
22-Nov-2003 10:24


If you open a truecolor image (with imageCreateFromPng for example), and you save it directly with imagegif, you can have a 500 internal server error. You must use imageTrueColorToPalette to reduce to 256 colors before saving the image in GIF format.

tom et lenderlab dit com
05-Dec-2002 01:08


The rgb2gif utility included in giflib can be used for fast and easy gif output with any version of GD

http://ietpd1.sowi.uni-mainz.de/cgi-bin/man2html?rgb2gif



use either the rgboutput or the rgboutput_truecolor functions, depending on your GD version/style of image you're working with:



<?

$x=40;

$y=40;



//make a simple image with some text

$im = imagecreate($x, $y);

$bg = imagecolorallocate($im, 0,0,0);

      imagefill($im, 0,0, $bg);



$red=imagecolorallocate($im, 255, 0, 0);

    imagestring($im, 1, 2, 8, "testing", $red);



//output the 24 bit rgb-formatted image to file

$f = fopen("image.rgb", "w");

fwrite($f, rgboutput($im));

imagedestroy($im);



//load that file into rgb2gif and capture the output

$status = `rgb2gif -1 -s $x $y image.rgb`;

$f = fopen("test.gif", "w");

fwrite($f, $status);



function rgboutput($im) {

    $x = imagesx($im);

    $y = imagesy($im);

    $output="";

    for($i=0;$i<$y;$i++) {

        for($j=0;$j<$x;$j++) {

            $c=ImageColorAt($im, $j, $i);

            $c = imagecolorsforindex($im, $c);

            $c = array_map("chr", $c);

            $output.=$c['red'].$c['green'].$c['blue'];

        }

    }

    return $output;

}



function rgboutput_truecolor($im) {

    $x = imagesx($im);

    $y = imagesy($im);

    $output="";

    for($i=0;$i<$y;$i++) {

        for($j=0;$j<$x;$j++) {

            $rgb=ImageColorAt($im, $j, $i);

            $r = chr(($rgb >> 16) & 0xFF);

            $g = chr(($rgb >> 8) & 0xFF);

            $b = chr($rgb & 0xFF);

            $output.=$r.$g.$b;

        }

    }

    return $output;

}

?><img src="test.gif">

polone at townnews dot com
03-Apr-2002 11:40


read also RFC2557: http://www.ietf.org/rfc/rfc2557.txt


For handling inline images in email.


----








I've been playing around with the "data" URL scheme as proposed by RFC 2397 which states how to perform inline, bas64 encoded images. A number of browsers support this format from some of my tests and would be an interesting way of removing overhead from multiple HTTP connections. Basically, the IMG tag would be:





<IMG SRC="/-/data:image/gif;base64,R0lGODdhMAAwAPAAAAAAAP///ywAAAAAMAAw AAAC8IyPqcvt3wCcDkiLc7C0qwyGHhSWpjQu5yqmCYsapyuvUUlvONmOZtfzgFz ByTB10QgxOR0TqBQejhRNzOfkVJ+5YiUqrXF5Y5lKh/DeuNcP5yLWGsEbtLiOSp a/TPg7JpJHxyendzWTBfX0cxOnKPjgBzi4diinWGdkF8kjdfnycQZXZeYGejmJl ZeGl9i2icVqaNVailT6F5iJ90m6mvuTS4OK05M0vDk0Q4XUtwvKOzrcd3iq9uis F81M1OIcR7lEewwcLp7tuNNkM3uNna3F2JQFo97Vriy/Xl4/f1cf5VWzXyym7PH hhx4dbgYKAAA7" ALT="Larry">





Something like that. Note also that I start the URI with "/-/" before the rest of the data scheme spec. If you don't start it with this, it won't work in a lot of the different browsers I tested (such as IE). Note this is useful for very small images only (as most browsers appear to have a limitation on the size of HTML element data of 1024). Browsers where this syntax worked that I tested are the following:





IE 6.x (windows)


Mozilla 0.97+ (linux)


Opera 5, 6 (windows)


Netscape 4.7+ (mac, windows)


IE 5 (macintosh)





This should work for other image types as well, such as PNG. JPEG files aren't really suggested (usually, these files are too large). BTW - there is no advantage to this method if the image will appear more than ONCE in the page because you will be transmitting the same data multiple times as opposed to just once (most browsers realize that already downloaded data that has multiple references only requires one HTTP call).





Consider using this method if you want to make a single PHP program that outputs both text and an image AND you want to make only on HTTP call. Cheers.

kremlin at home dot com
26-Feb-2001 09:45


Animated GIFs as well as transparent GIFs qualify as GIF89a's and you should use ImageColorTransparent().

danny at arbitrary dot com
22-Aug-2000 02:31


If you want to have a page with dynamic text and a dynamic image based on one form, use two php's.  One is the page which has a call to the other in an img tag:


<img src="myImage.php?name=value...

david at hooshla dot com
28-Apr-2000 07:45


This is how you load and display an image file:





<?


Header("Content-Type: image/gif");


$fn=fopen("./imagefile.gif","r");


fpassthru($fn);


?>





Note that there are no new-lines in the content type header.

till at comets dot de
03-Nov-1999 08:48


ImageGIF() outputs an image created by PHP. Since php cannot create animated or multiple images in a single file 


it cannot handle animated GIFs. 


To read GIF images use the function ImageCreateFromGIF.





--marcus





imagegif doesn't seem to work on "animated" gifs. .-(