Convert jpg to webp using imagewebp - php

Question

I'm having trouble using imagewebp to convert an image to webp.
I use this code:
$filename = dirname(__FILE__) .'/example.jpg';
$im = imagecreatefromjpeg($filename);
$webp =imagewebp($im, str_replace('jpg', 'webp', $filename));
imagedestroy($im);
var_dump($webp);
$webp returns true but when I try to view the webp-image in Chrome it just shows blank, but with the correct size. If I instead load the image and set headers with PHP (see below) it shows up, but with wrong colors (too much yellow).
$im = imagecreatefromwebp('example.webp');
header('Content-Type: image/webp');
imagewebp($im);
imagedestroy($im);
If I convert the same image with command line it works as expected.
cwebp -q 100 example.jpg -o example.webp
I'm testing this on Ubuntu 14, Apache 2.4.7 and PHP 5.5.9-1ubuntu4.4.

Answer 1

It works:
$jpg=imagecreatefromjpeg('filename.jpg');
$w=imagesx($jpg);
$h=imagesy($jpg);
$webp=imagecreatetruecolor($w,$h);
imagecopy($webp,$jpg,0,0,0,0,$w,$h);
imagewebp($webp, 'filename.webp', 80);
imagedestroy($jpg);
imagedestroy($webp);

Answer 2

I had same problem, my solution is:
$file='hnbrnocz.jpg';
$image= imagecreatefromjpeg($file);
ob_start();
imagejpeg($image,NULL,100);
$cont= ob_get_contents();
ob_end_clean();
imagedestroy($image);
$content = imagecreatefromstring($cont);
imagewebp($content,'images/hnbrnocz.webp');
imagedestroy($content);

Answer 3

I user this
function webpConvert2($file, $compression_quality = 80)
{
// check if file exists
if (!file_exists($file)) {
return false;
}
$file_type = exif_imagetype($file);
//https://www.php.net/manual/en/function.exif-imagetype.php
//exif_imagetype($file);
// 1 IMAGETYPE_GIF
// 2 IMAGETYPE_JPEG
// 3 IMAGETYPE_PNG
// 6 IMAGETYPE_BMP
// 15 IMAGETYPE_WBMP
// 16 IMAGETYPE_XBM
$output_file = $file . '.webp';
if (file_exists($output_file)) {
return $output_file;
}
if (function_exists('imagewebp')) {
switch ($file_type) {
case '1': //IMAGETYPE_GIF
$image = imagecreatefromgif($file);
break;
case '2': //IMAGETYPE_JPEG
$image = imagecreatefromjpeg($file);
break;
case '3': //IMAGETYPE_PNG
$image = imagecreatefrompng($file);
imagepalettetotruecolor($image);
imagealphablending($image, true);
imagesavealpha($image, true);
break;
case '6': // IMAGETYPE_BMP
$image = imagecreatefrombmp($file);
break;
case '15': //IMAGETYPE_Webp
return false;
break;
case '16': //IMAGETYPE_XBM
$image = imagecreatefromxbm($file);
break;
default:
return false;
}
// Save the image
$result = imagewebp($image, $output_file, $compression_quality);
if (false === $result) {
return false;
}
// Free up memory
imagedestroy($image);
return $output_file;
} elseif (class_exists('Imagick')) {
$image = new Imagick();
$image->readImage($file);
if ($file_type === "3") {
$image->setImageFormat('webp');
$image->setImageCompressionQuality($compression_quality);
$image->setOption('webp:lossless', 'true');
}
$image->writeImage($output_file);
return $output_file;
}
return false;
}