(PHP 4, PHP 5)
imagegif — Invia l'immagine al browser o in un file
$image
[, string $filename
] )
imagegif() creates the GIF
file in filename from the image image. The
image argument is the return from the
imagecreate() or imagecreatefrom*
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.
imageUna risorsa immagine, restituita da una delle funzioni di creazione immagine, come imagecreatetruecolor().
filenameIl percorso in cui salvare il file. Se non è impostato o è NULL, viene restituito il flusso raw dell'immagine.
Restituisce TRUE in caso di successo, FALSE in caso di fallimento.
Example #1 Outputting an image using imagegif()
<?php
// Create a new image instance
$im = imagecreatetruecolor(100, 100);
// Make the background white
imagefilledrectangle($im, 0, 0, 99, 99, 0xFFFFFF);
// Draw a text string on the image
imagestring($im, 3, 40, 20, 'GD Library', 0xFFBA00);
// Output the image to browser
header('Content-Type: image/gif');
imagegif($im);
imagedestroy($im);
?>
Example #2 Converting a PNG image to GIF using imagegif()
<?php
// Load the PNG
$png = imagecreatefrompng('./php.png');
// Save the image as a GIF
imagegif($png, './php.gif');
// Free from memory
imagedestroy($png);
// We're done
echo 'Converted PNG image to GIF with success!';
?>
Nota:
GIF support was removed from the GD library in Version 1.6, and added back in Version 2.0.28. This function is not available between these versions. For more information, see the » GD Project site.
The following code snippet allows you to write more portable PHP applications by auto-detecting the type of GD support which is available. Replace the sequence header ("Content-Type: image/gif"); imagegif ($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);
}
?>
Nota:
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. */
}
?>