CascadiaPHP 2024

imagewebp

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

imagewebpMostra uma imagem WebP no navegador ou grava em arquivo

Descrição

imagewebp(GdImage $image, resource|string|null $file = null, int $quality = -1): bool

Motra ou grava uma versão WebP da imagem informada em image.

Parâmetros

image

Um objeto GdImage, retornado por uma das funções de criação de imagem, como imagecreatetruecolor().

file

O caminho ou um recurso de stream aberto (que será fechado automaticamente após o retorno desta função) para salvar o arquivo. Se não for definido ou for null, o stream da imagem bruta será enviado diretamente.

quality

quality varia de 0 (pior qualidade, arquivo menor) a 100 (melhor qualidade, arquivo maior).

Valor Retornado

Retorna true em caso de sucesso ou false em caso de falha.

Cuidado

Entretanto, se a biblioteca libgd falhar ao gerar a imagem, esta função retornará true.

Registro de Alterações

Versão Descrição
8.0.0 O parâmetro image agora espera uma instância de GdImage; anteriormente, um resource gd válido era esperado.

Exemplos

Exemplo #1 Gravando um arquivo WebP

<?php
// Cria uma imagem vazia e adiciona texto
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);

imagestring($im, 1, 5, 5, 'WebP with PHP', $text_color);

// Grava a imagem
imagewebp($im, 'php.webp');

// Libera a memória
imagedestroy($im);
?>

add a note

User Contributed Notes 7 notes

up
30
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);

?>
up
33
Khalyomede
5 years ago
As of today (end of january 2019), WebP is now supported across all the major browsers (Edge, Chrome, Firefox, Opera).
up
18
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;
}
up
8
day4gerard
4 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.
up
1
Sam
2 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
up
-8
orangefish at sogetthis dot com
10 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!)
up
-8
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.
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