imagegif

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

imagegifInvia l'immagine al browser o in un file

Descrizione

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

imagegif() creates the GIF file in file 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.

Elenco dei parametri

image

Una risorsa immagine, restituita da una delle funzioni di creazione immagine, come imagecreatetruecolor().

file

Il percorso in cui salvare il file. Se non è impostato o è null, viene restituito il flusso raw dell'immagine.

Valori restituiti

Restituisce true in caso di successo, false in caso di fallimento.

Attenzione

However, if libgd fails to output the image, this function returns true.

Log delle modifiche

Versione Descrizione
8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.

Esempi

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);
?>

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');

// We're done
echo 'Converted PNG image to GIF with success!';
?>

Note

Nota:

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

Nota:

You can use the function imagetypes() 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. */
}
?>

Vedere anche:

  • imagepng() - Output a PNG image to either the browser or a file
  • imagewbmp() - Invia l'immagine al browser o in un file
  • imagejpeg() - Invia l'immagine al browser o in un file
  • imagetypes() - Return the image types supported by this PHP build