imagegrabscreen

imagegd

Last updated: Fri, 11 Apr 2008

imagegif

(PHP 4, PHP 5)

imagegif — Producir la salida de una imagen al navegador o a un archivo

Descripción

bool imagegif ( resource $imagen [, string $nombre_archivo ] )

imagegif() crea el archivo GIF indicado por nombre_archivo desde la imagen imagen . El parámetro imagen es el valor de retorno de la función imagecreate() o imagecreatefrom*.

El formato de la imagen será GIF87a a menos que la imagen haya sido convertida a transparente con imagecolortransparent(), en cuyo caso el formato de la imagen será GIF89a.

Lista de parámetros

image: An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
nombre_archivo: La ruta usada para guardar el archivo. Si no se define o se usa el valor NULL, la secuencia pura de la imagen será enviada a la salida directamente.

Valores retornados

Devuelve TRUE si todo se llevó a cabo correctamente, FALSE en caso de fallo.

Notes

Note: Dado que el soporte GIF fue retirado por completo de la biblioteca GD en la versión 1.6, esta función no se encuentra disponible si está usando tal versión de la biblioteca GD. Se espera que el soporte para esta característica regrese en una versión posterior al relanzamiento del soporte GIF en la biblioteca GD a mediados de 2004. Para más información, consulte el sitio web del » Proyecto GD.
El siguiente segmento de código le permite escribir aplicaciones PHP más portables al detectar automáticamente el tipo de soporte GD que se encuentra disponible. Reemplace la secuencia header ("Content-type: image/gif"); imagegif ($im); por la secuencia más flexible:

<?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 hay soporte de imágenes en este servidor PHP"); } ?>

Note: A partir de la versión 3.0.18 y 4.0.2 puede usar la función imagetypes() en lugar de function_exists() para chequear por la presencia de los varios formatos de imagen soportados:

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

Ver también

imagegrabscreen

imagegd

Last updated: Fri, 11 Apr 2008

add a note User Contributed Notes
imagegif

serhio_forever at yahoo dot com
13-Feb-2008 03:24


Note that when converting some transparent png to a gif image , it won't be transparent , don't know why...



from gif to png works fine with :

    $img = imagecreatefromgif($name);



    $x = imageSX($img);

    $y = imageSY($img);

    $new_img = ImageCreateTrueColor($x, $y);

    imagealphablending($new_img, false);

    $colorTransparent = imagecolorallocatealpha($new_img, 0, 0, 0, 127);

    imagefill($new_img, 0, 0, $colorTransparent);

    imagesavealpha($new_img, true);

    imagepng($new_img, $dest, 5);

alan hogan dot com slash contact
12-Nov-2007 11:47


Note that you *can* save with a transparent color **and dither** using GD2.

For a useful example, see the png-to-gif function in my coment here:

http://www.php.net/manual/en/function.imagecolorat.php

rokfaith at gmail dot com
14-Aug-2006 03:33


I've recieved e-mails on this, so i will elaborate (original post ~2 posts down):

the RenderFrame($frame) function should be a function that returns an image resource and does something sensibe with the integer (frame number) that it gets passed.



function RenderFrame($frame) {

  $im = imagecreatetruecolor(100,100); //or just imagecreate for smaller images

  imageantialias($im, true); //works only on true color images, slower

  //draw something on image (imageline, imagerect, imageftt...)

  return $im;

}



this way the image is drawn and destroyed every iteration of the loop, so you can animate moving things, eg. text. if you keep the image between function calls, you get the effect of progressively drawing the image:

change

   $im = imagecreatetruecolor(100,100); 

into

  static $im = imagecreatetruecolor(100,100);

2ge at 2ge dot us
13-Aug-2006 11:02


Hello,



there is many guides how to make animated gif (with or without temp files), but I found this really nice solution, it uses no patched GD, no external utils, just pure PHP. Look into http://www.phpclasses.org/browse/package/3163.html 



Hope this helps.

rokfaith at gmail dot com
07-Jul-2006 12:34


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 02:12


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 12:54


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 01:02


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
04-Jul-2005 02:17


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 06:25


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 07:24


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 10:08


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 09:40


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
27-Feb-2001 06:45


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

danny at arbitrary dot com
22-Aug-2000 11:31


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
29-Apr-2000 04:45


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.

add a note

imagegrabscreen

imagegd

Last updated: Fri, 11 Apr 2008