As of today (end of january 2019), WebP is now supported across all the major browsers (Edge, Chrome, Firefox, Opera).
imagewebp
(PHP 5 >= 5.4.0, PHP 7, PHP 8)
imagewebp — Output a WebP image to browser or file
Descrizione
Outputs or saves a WebP version of the given image.
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. -
quality -
qualityranges from 0 (worst quality, smaller file) to 100 (best quality, biggest file).
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 Saving an WebP file
<?php
// Create a blank image and add some text
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5, 'WebP with PHP', $text_color);
// Save the image
imagewebp($im, 'php.webp');
// Free up memory
imagedestroy($im);
?>
add a note
User Contributed Notes 7 notes
Khalyomede ¶
5 years ago
vinicius dot sizilio at gmail dot com ¶
4 years ago
To convert a PNG image to Webp, we can do this:
<?php
// Image
$dir = 'img/countries/';
$name = 'brazil.png';
$newName = 'brazil.webp';
// Create and save
$img = imagecreatefrompng($dir . $name);
imagepalettetotruecolor($img);
imagealphablending($img, true);
imagesavealpha($img, true);
imagewebp($img, $dir . $newName, 100);
imagedestroy($img);
?>
JSix ¶
2 years ago
Function to save any image to Webp
public static function webpImage($source, $quality = 100, $removeOld = false)
{
$dir = pathinfo($source, PATHINFO_DIRNAME);
$name = pathinfo($source, PATHINFO_FILENAME);
$destination = $dir . DIRECTORY_SEPARATOR . $name . '.webp';
$info = getimagesize($source);
$isAlpha = false;
if ($info['mime'] == 'image/jpeg')
$image = imagecreatefromjpeg($source);
elseif ($isAlpha = $info['mime'] == 'image/gif') {
$image = imagecreatefromgif($source);
} elseif ($isAlpha = $info['mime'] == 'image/png') {
$image = imagecreatefrompng($source);
} else {
return $source;
}
if ($isAlpha) {
imagepalettetotruecolor($image);
imagealphablending($image, true);
imagesavealpha($image, true);
}
imagewebp($image, $destination, $quality);
if ($removeOld)
unlink($source);
return $destination;
}
day4gerard ¶
5 years ago
WebP is not yet supported by Safari, although they are experimenting with it.
Check out https://caniuse.com/#search=webp for the latest support information.
Sam ¶
3 years ago
Safari on mac now has limited support (limited to Safari 14+ on Big Sur or later)
Safari on iOS 14.4 and higher has full support
orangefish at sogetthis dot com ¶
11 years ago
WebP is a great file format, but it's basically supported only by Chrome. For WebP files with transparency it's necessary to have PNG fallback for other browsers (otherwise it won't work in iOS, Firefox, IE, etc.).
Regular truecolor PNG with alpha gives pretty large files, but there's a special smaller PNG file variant that can be created by pngquant - a command line utility.
If you have pngquant 1.8 on your server (just get package from official pngquant website), then you can create small fallback images (with quality better than from PHP's libgd):
<?php
/**
* Optimizes PNG file with pngquant 1.8 or later (reduces file size of 24-bit/32-bit PNG images).
*
* You need to install pngquant 1.8.x on the server (ancient version 1.0 won't work).
* There's package for Debian/Ubuntu and RPM for other distributions on http://pngquant.org
*
* @param $path_to_png_file string - path to any PNG file, e.g. $_FILE['file']['tmp_name']
* @param $max_quality int - conversion quality, useful values from 60 to 100 (smaller number = smaller file)
* @return string - content of PNG file after conversion
*/
function compress_png($path_to_png_file, $max_quality = 90)
{
if (!file_exists($path_to_png_file)) {
throw new Exception("File does not exist: $path_to_png_file");
}
// guarantee that quality won't be worse than that.
$min_quality = 60;
// '-' makes it use stdout, required to save to $compressed_png_content variable
// '<' makes it read from the given file path
// escapeshellarg() makes this safe to use with any path
$compressed_png_content = shell_exec("pngquant --quality=$min_quality-$max_quality - < ".escapeshellarg( $path_to_png_file));
if (!$compressed_png_content) {
throw new Exception("Conversion to compressed PNG failed. Is pngquant 1.8+ installed on the server?");
}
return $compressed_png_content;
}
?>
So for example when user is uploading a PNG file:
<?php
$read_from_path = $_FILE['file']['tmp_name'];
$save_to_path = "uploads/compressed_file.png";
$compressed_png_content = compress_png($read_from_path);
file_put_contents($save_to_path, $compressed_png_content);
// you don't need move_uploaded_file().
// and for webp:
imagewebp(imagecreatefrompng($read_from_path), $save_to_path + ".webp");
?>
And then you can use URL with .webp version in Chrome and browsers that send Accept: image/webp, and .png for the rest (and all will get small file!)
mauro dot ludovico dot colella at gmail dot com ¶
9 years ago
It is also possible to defer the creation of png replacements for WebP images to the client, with notably the library libwebpjs enabling transparent conversion.
