webp with transparency

how to keep transparency from PNG to WEBP ?
I use code for thumbnail

add_filter('wp_generate_attachment_metadata', 'custom_webp_thumb');

function custom_webp_thumb($metadata) {
	// URL
	$uploads = wp_upload_dir();	 // 
	$path_parts  = pathinfo($metadata['file']);  // for 2018/10
	
	$file = path_join( $uploads['basedir'], $path_parts['dirname'].'/'. $metadata["sizes"]["medium"]["file"] ); // original image file
	$image = imagecreatefrompng($file); // or imagecreatefromjpeg
	
//	imagepalettetotruecolor($image); - not help 
//	imagealphablending($image, false); - not help 
//	imagesavealpha($image, true); - not help 
		
	// Save the image
	imagewebp($image, '/home/****/2018/10/'.$metadata["sizes"]["medium"]["file"].'.webp');
	// unlink($file);
	
	return $metadata;
}

pictures are obtained with a black and not transparent background

——— PNG with transparency ————- WEBP with Black background —–

• This topic was modified 7 years, 7 months ago by kolshix.
• This topic was modified 7 years, 7 months ago by kolshix.
• This topic was modified 7 years, 7 months ago by kolshix.