imagecreatefromwebp

(PHP 5 >= 5.4.0, PHP 7, PHP 8)

imagecreatefromwebpCrea una nuova immagine da un file o una URL

Descrizione

imagecreatefromwebp(string $filename): GdImage|false

imagecreatefromwebp() returns an image identifier representing the image obtained from the given filename. Note that animated WebP files cannot be read.

Suggerimento

È possibile utilizzare una URL come un nome di file con questa funzione se fopen wrappers è stata abilitata. Vedere fopen() per maggiori informazioni su come specificare i nomi di file. Vedere Supported Protocols and Wrappers per i link verso le informazioni sulle capacità dei vari wrapper, note sul loro uso, informazioni sulle variabili predefinite che forniscono.

Elenco dei parametri

filename

Path to the WebP image.

Valori restituiti

Restituisce un identificatore di risorsa immagine, false in caso di errore.

Log delle modifiche

Versione Descrizione
8.0.0 On success, this function returns a GDImage instance now; previously, a resource was returned.

Esempi

Example #1 Convert an WebP image to a jpeg image using imagecreatefromwebp()

<?php
// Load the WebP file
$im imagecreatefromwebp('./example.webp');

// Convert it to a jpeg file with 100% quality
imagejpeg($im'./example.jpeg'100);
imagedestroy($im);
?>

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User Contributed Notes 1 note

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kawewong at gmail dot com
1 year ago
PHP GD and WebP support:

Normal WebP (VP8): supported since PHP 5.4
Transparent WebP or alpha transparency (VP8X, VP8L): supported since PHP 7.0
Animated WebP (VP8X): not supported at all.

You can use the images from here https://developers.google.com/speed/webp/gallery2
here https://ezgif.com/help/alternative-animated-image-formats
and here https://developers.google.com/speed/webp/gallery1

Test with imagecreatefromwebp('your-image.webp'); and see the errors.

You can detect animated or transparent webp using this code.

<?php
/**
* Get WebP file info.
*
* @link https://www.php.net/manual/en/function.pack.php unpack format reference.
* @link https://developers.google.com/speed/webp/docs/riff_container WebP document.
* @param string $file
* @return array|false Return associative array if success, return `false` for otherwise.
*/
function webpinfo($file) {
    if (!
is_file($file)) {
        return
false;
    } else {
       
$file = realpath($file);
    }

   
$fp = fopen($file, 'rb');
    if (!
$fp) {
        return
false;
    }

   
$data = fread($fp, 90);

   
fclose($fp);
    unset(
$fp);

   
$header_format = 'A4Riff/' . // get n string
       
'I1Filesize/' . // get integer (file size but not actual size)
       
'A4Webp/' . // get n string
       
'A4Vp/' . // get n string
       
'A74Chunk';
   
$header = unpack($header_format, $data);
    unset(
$data, $header_format);

    if (!isset(
$header['Riff']) || strtoupper($header['Riff']) !== 'RIFF') {
        return
false;
    }
    if (!isset(
$header['Webp']) || strtoupper($header['Webp']) !== 'WEBP') {
        return
false;
    }
    if (!isset(
$header['Vp']) || strpos(strtoupper($header['Vp']), 'VP8') === false) {
        return
false;
    }

    if (
       
strpos(strtoupper($header['Chunk']), 'ANIM') !== false ||
       
strpos(strtoupper($header['Chunk']), 'ANMF') !== false
   
) {
       
$header['Animation'] = true;
    } else {
       
$header['Animation'] = false;
    }

    if (
strpos(strtoupper($header['Chunk']), 'ALPH') !== false) {
       
$header['Alpha'] = true;
    } else {
        if (
strpos(strtoupper($header['Vp']), 'VP8L') !== false) {
           
// if it is VP8L, I assume that this image will be transparency
            // as described in https://developers.google.com/speed/webp/docs/riff_container#simple_file_format_lossless
           
$header['Alpha'] = true;
        } else {
           
$header['Alpha'] = false;
        }
    }

    unset(
$header['Chunk']);
    return
$header;
}
// webpinfo
?>

Reference: https://stackoverflow.com/a/68491679/128761

Usage:

<?php
$info
= webpinfo('your-image.webp');
if (isset(
$info['Animation']) && $info['Animation'] === true) {
    echo
'It is animated webp.';
}
if (isset(
$info['Alpha']) && $info['Alpha'] === true) {
    echo
'It is transparent webp.';
}
?>
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