imagegif

(PHP 4, PHP 5, PHP 7, PHP 8)

imagegif — Envia a imagem para o navegador ou para um arquivo

Descrição

imagegif(GdImage $image, resource|string|null $file = null): bool

imagegif() cria o arquivo GIF especificado em file a partir da imagem em image. O argumento image é o retorno da função imagecreate() ou imagecreatefrom*.

O formato da imagem será GIF87a a menos que a imagem tenha se tornado transparente com imagecolortransparent(), e neste caso o formato da imagem será GIF89a.

Parâmetros

image: Um objeto GdImage, retornado por uma das funções de criação de imagem, como imagecreatetruecolor().
file: O caminho ou um recurso de stream aberto (que será fechado automaticamente após o retorno desta função) para salvar o arquivo. Se não for definido ou for null, o stream da imagem bruta será enviado diretamente.

Valor Retornado

Retorna true em caso de sucesso ou false em caso de falha.

Cuidado

Entretanto, se a biblioteca libgd falhar ao gerar a imagem, esta função retornará true.

Registro de Alterações

Versão	Descrição
8.0.0	O parâmetro `image` agora espera uma instância de GdImage; anteriormente, um resource `gd` válido era esperado.

Exemplos

Exemplo #1 Mostrando uma imagem usando imagegif()

<?php
// Cria uma nova instância de imagem
$im = imagecreatetruecolor(100, 100);

// Deixa o fundo branco
imagefilledrectangle($im, 0, 0, 99, 99, 0xFFFFFF);

// Desenha uma string na imagem
imagestring($im, 3, 40, 20, 'GD Library', 0xFFBA00);

// Mostra a imagem no navegador
header('Content-Type: image/gif');

imagegif($im);
imagedestroy($im);
?>

Exemplo #2 Convertendo uma imagem PNG para GIF usando imagegif()

<?php

// Carrega o PNG
$png = imagecreatefrompng('./php.png');

// Grava a imagem como GIF
imagegif($png, './php.gif');

// Libera a memória
imagedestroy($png);

// Pronto
echo 'Convertida a imagem PNG para GIF com sucesso!';
?>

Notas

Nota:
O extrato de código a seguir permite esrever aplicações PHP mais portáveis através de auto-detecção do tipo de suporte GD disponível. Substitua sequência header ("Content-Type: image/gif"); imagegif ($im); pela sequência mais flexível:

<?php // Cria uma nova instância de imagem $im = imagecreatetruecolor(100, 100); // Faz aqui algumas operações // Lida com a saída if(function_exists('imagegif')) { // Para GIF header('Content-Type: image/gif'); imagegif($im); } elseif(function_exists('imagejpeg')) { // Para JPEG header('Content-Type: image/jpeg'); imagejpeg($im, NULL, 100); } elseif(function_exists('imagepng')) { // Para PNG header('Content-Type: image/png'); imagepng($im); } elseif(function_exists('imagewbmp')) { // Para WBMP header('Content-Type: image/vnd.wap.wbmp'); imagewbmp($im); } else { imagedestroy($im); die('Não existe suporte para imagem neste servidor PHP'); } // Se o suporte a imagem foi encontrado para um destes // formatos, libera-se a memória if($im) { imagedestroy($im); } ?>

Nota:
Pode-se usar a função imagetypes() para verificar a presenção de vários formatos de imagem suportados:

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

Veja Também

imagepng() - Envia uma imagem PNG para o navegador ou arquivo
imagewbmp() - Envia a imagem para o navegador ou para um arquivo
imagejpeg() - Envia a imagem para o navegador ou para um arquivo
imagetypes() - Retorna os tipos de imagens suportados pela instalação do PHP

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User Contributed Notes 12 notes

down

polone at townnews dot com ¶

22 years ago


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.

down

coldume ¶

11 years ago


To keep GIF animation, you can try the class writing based on GD 
GD Enhancer http://www.gdenhancer.com/

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stefan at colulus dot com ¶

16 years ago


I worked out a script that allows the transfer of alphanumeric data to be placed on an image. The HTML feature is img src and the php feature is imagettftext. This simple code will increment from 1 to 3 on images.

code:

<?php
//ImageCall.php -- This script will call a script to produce the image.
for($next = 1;$next < 4; $next++){
print "Image $next:<br>";
print "<img src = 'Image.php?\$text=$next'>";
print "<br><br>";
}
?>

<?php
//Image.php -- This script creates a square image and places the text on it.

// image size and color
$im = ImageCreate(77,77);
$color1 = ImageColorAllocate($im,0x66,0xCC,0x00);
$color2 = ImageColorAllocate($im,0x33,0x66,0x00);
$color3 = ImageColorAllocate($im,0x00,0x99,0x00);
$color4 = ImageColorAllocate($im,0x3D,0x3D,0x3D);

// image creation
ImageFilledRectangle($im,1,1,76,76,$color1);
ImageFilledpolygon($im, array (76,1,1,76,76,76),3,$color2);
ImageFilledRectangle($im,5,5,72,72,$color3);

// determine numeric center of image
$size = ImageTTFBBox(45,0,'impact',$_GET['$text']);
$X = (77 - (abs($size[2]- $size[0])))/2;
$Y = ((77 - (abs($size[5] - $size[3])))/2 + (abs($size[5] - $size[3])));

//places numeric information on image
ImageTTFText($im,45,0,($X-1),$Y,$color4,'impact',$_GET['$text']);

//returns completed image to calling script
Header('Content-Type: image/png');
Imagegif($im);

?>

down

rokfaith at gmail dot com ¶

18 years ago


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



<?php

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

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mail at ignore dot area dot nospam dot joshho dot com ¶

12 years ago


apparently GD does not support animated GIFs.



instead, we're stuck with the old fashioned way:

<?php

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

echo file_get_contents($destPathImage);

?>

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kremlin at home dot com ¶

23 years ago


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

down

-1

jemore at nospam dot m6net dot fr ¶

21 years ago


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.

down

-1

grant k. ¶

14 years ago


It should be noted that if you only want to "save" the file, and not display it to the browser, you should catch the imagegif into a variable.



Example:



<?php

//Only saves the file to a destination, no display



$image_value = imagegif($image, $save_file_to_path);



//Saves file and attempts to display it, but will throw an error message



imagegif($image, $save_file_to_path);

    

//Only displays, never saves as a file

imagegif($image);



//Note: In [my] third example, for displaying only, it is probably good to use the "header('Content-type: image/gif'); declaration, but it's not needed in the first example for saving as a .gif file.

?>

down

-1

Lauri Harpf ¶

19 years ago


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.

down

-6

Leigh Purdie ¶

19 years ago


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>

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-4

alan hogan dot com slash contact ¶

17 years ago


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

down

-5

david at hooshla dot com ¶

24 years ago


This is how you load and display an image file:



<?php

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

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

fpassthru($fn);

?>



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

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