imagegif

주의

Note: 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
// Create a new image instance
$im = imagecreatetruecolor(100, 100);

// Do some image operations here

// Handle output
if(function_exists('imagegif'))
{
    // For GIF
    header('Content-type: image/gif');

    imagegif($im);
}
elseif(function_exists('imagejpeg'))
{
    // For JPEG
    header('Content-type: image/jpeg');

    imagejpeg($im, NULL, 100);
}
elseif(function_exists('imagepng'))
{
    // For PNG
    header('Content-type: image/png');

    imagepng($im);
}
elseif(function_exists('imagewbmp'))
{
    // For WBMP
    header('Content-type: image/vnd.wap.wbmp');

    imagewbmp($im);
}
else
{
    imagedestroy($im);

    die('No image support in this PHP server');
}

// If image support was found for one of these
// formats, then free it from memory
if($im)
{
    imagedestroy($im);
}
?>

Note: As of PHP 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. */
}
?>