webp格式的图片有点我就不说了，不明白的可以看看下面的描述：
WebP，是一种同时提供了有损压缩与无损压缩的图片文件格式，派生自视频编码格式 VP8。WebP 最初在2010年发布，目标是减少文件大小，但达到 和 JEPG 格式相同的图片质量，希望能够减少图片档在网络上的发送时间。2011年11月8日，Google 开始让 WebP 支持无损压缩和透明色的功能。
现在很多站点已经开始使用这个格式的图片作为主力，但是我个人还是比较推荐保留两种格式，毕竟不是所有人都喜欢webp格式的文件，同时存在源文件格式和webp格式文件才是最优解，毕竟现在的硬盘空间已经不值钱了。
看了上面的所有说明，你没有顾虑，可以看看下面的代码：
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<?php /** * Plugin Name: GD WebP Converter * Plugin URI: https://stackoverflow.com/a/67234000 * Description: After uploading an image it will be converted to WebP format using the GD image engine. <a target="_blank" href="https://developer.wordpress.org/reference/classes/wp_image_editor_gd/" rel="noopener">WP GD Image Engine</a> If the file is deleted form the Media Library the created WebP conversions will also be deleted. * Version: 1.0.0 * Requires at least: 5.5 * Requires PHP: 7.2 * Author: lowtechsun * Author URI: https://stackoverflow.com/users/1010918/lowtechsun * License: GPL v2 or later * License URI: https://www.gnu.org/licenses/gpl-2.0.html */ //================================================= // Security: Abort if this file is called directly //================================================= if ( ! defined( 'ABSPATH' ) ) { die; } function debug( $info ) { $message = null; if ( is_string( $info ) || is_int( $info ) || is_float( $info ) ) { $message = $info; } else { $message = var_export( $info, true ); } if ( $fh = fopen( ABSPATH . '/gdwebpconvert.log', 'a' ) ) { fputs( $fh, date( 'Y-m-d H:i:s' ) . " $message\n" ); fclose( $fh ); } } add_filter( 'wp_generate_attachment_metadata', 'gd_webp_converter', 10, 2 ); function gd_webp_converter( $metadata, $attachment_id ) { $gd_webp_converter = new GDWebPConverter( $attachment_id ); $gd_webp_converter->check_file_exists( $attachment_id ); $gd_webp_converter->check_mime_type(); $gd_webp_converter->create_array_of_sizes_to_be_converted( $metadata ); $gd_webp_converter->convert_array_of_sizes(); return $metadata; } class GDWebPConverter { private $file_path; private $file_dirname; private $file_ext; private $file_name_no_ext; private $array_of_sizes_to_be_converted = array(); private $array_of_sizes_to_be_deleted = array(); public function __construct( $attachment_id ) { $this->file_path = get_attached_file( $attachment_id ); debug( $this->file_path ); // https://stackoverflow.com/questions/2183486/php-get-file-name-without-file-extension/19040276 $this->file_dirname = pathinfo( $this->file_path, PATHINFO_DIRNAME ); debug( $this->file_dirname ); $this->file_ext = strtolower( pathinfo( $this->file_path, PATHINFO_EXTENSION ) ); debug( $this->file_ext ); $this->file_name_no_ext = pathinfo( $this->file_path, PATHINFO_FILENAME ); debug( $this->file_name_no_ext ); } public function check_file_exists( $attachment_id ) { $file = get_attached_file( $attachment_id ); if ( ! file_exists( $file ) ) { $message = 'The uploaded file does not exist on the server. Encoding not possible.'; debug( $message ); throw new Exception( 'The uploaded file does exist on the server. Encoding not possible.', 1 ); } } public function check_mime_type() { // https://www.php.net/manual/en/function.finfo-file.php $finfo = finfo_open( FILEINFO_MIME_TYPE ); $this->file_mime_type = finfo_file( $finfo, $this->file_path ); finfo_close( $finfo ); // debug( $this->file_mime_type ); // https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types $this->allowed_mime_type = array( 'image/jpeg', 'image/png' ); if ( ! in_array( $this->file_mime_type, $this->allowed_mime_type, true ) ) { $message = 'MIME type of file not supported'; // debug( $message ); throw new Exception( 'MIME type of file not supported', 1 ); } } public function create_array_of_sizes_to_be_converted( $metadata ) { // push original file to the array array_push( $this->array_of_sizes_to_be_converted, $this->file_path ); // debug( $this->array_of_sizes_to_be_converted ); // push all created sizes of the file to the array foreach ( $metadata['sizes'] as $value ) { // debug( $value['file'] ); array_push( $this->array_of_sizes_to_be_converted, $this->file_dirname . '/' . $value['file'] ); } // // debug( $this->array_of_sizes_to_be_converted ); } public function convert_array_of_sizes() { debug( $this->array_of_sizes_to_be_converted ); switch ( $this->file_ext ) { case 'jpeg': case 'jpg': foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) { $image = imagecreatefromjpeg( $value ); if ( 0 === $key ) { imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 ); } else { $current_size = getimagesize( $value ); // debug( $current_size ); imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 ); } imagedestroy( $image ); } break; case 'png': foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) { $image = imagecreatefrompng( $value ); imagepalettetotruecolor( $image ); imagealphablending( $image, true ); imagesavealpha( $image, true ); if ( 0 === $key ) { imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 ); } else { $current_size = getimagesize( $value ); // debug( $current_size ); imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 ); } imagedestroy( $image ); } break; // animated GIF to WebP not supported by GD - imagecreatefromgif // case 'gif': // foreach ( $this->array_of_sizes_to_be_converted as $key => $value ) { // $image = imagecreatefromgif( $value ); // if ( 0 === $key ) { // imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp', 80 ); // } else { // $current_size = getimagesize( $value ); // // debug( $current_size ); // imagewebp( $image, $this->file_dirname . '/' . $this->file_name_no_ext . '-' . $current_size[0] . 'x' . $current_size[1] . '.webp', 80 ); // } // imagedestroy( $image ); // } // break; default: return false; } } public function create_array_of_sizes_to_be_deleted( $attachment_id ) { // debug( $attachment_id ); $this->attachment_metadata_of_file_to_be_deleted = wp_get_attachment_metadata( $attachment_id ); // debug( $this->attachment_metadata_of_file_to_be_deleted ); // push original file to the array array_push( $this->array_of_sizes_to_be_deleted, $this->file_dirname . '/' . $this->file_name_no_ext . '.webp' ); // debug( $this->array_of_sizes_to_be_converted ); // push all created sizes of the file to the array foreach ( $this->attachment_metadata_of_file_to_be_deleted['sizes'] as $value ) { // debug( $value ); $this->value_file_name_no_ext = pathinfo( $value['file'], PATHINFO_FILENAME ); // debug( $this->value_file_name_no_ext ); array_push( $this->array_of_sizes_to_be_deleted, $this->file_dirname . '/' . $this->value_file_name_no_ext . '.webp' ); } // debug( $this->array_of_sizes_to_be_deleted ); } public function delete_array_of_sizes() { debug( $this->array_of_sizes_to_be_deleted ); foreach ( $this->array_of_sizes_to_be_deleted as $key => $value ) { // debug( $value ); unlink( $value ); } } } add_action( 'delete_attachment', 'delete_webp_conversions', 10 ); function delete_webp_conversions( $attachment_id ) { $delete_webp_conversions = new GDWebPConverter( $attachment_id ); $delete_webp_conversions->create_array_of_sizes_to_be_deleted( $attachment_id ); $delete_webp_conversions->delete_array_of_sizes(); } |
经过测试之后，上传图片确实是可以在后台生成对应的webp图片，效果截图如下：
同样的，你可以尝试一下，上方的图片修改后缀为webp同样可以看到图片。
上面的代码直接保存为一个php文件之后，在function文件中通过include导入即可完成该功能。
[hong unique_number=”hong_c7763c9c91264932b1f2339b58d88053″]
经过尝试，这里需要注意的就是PHP方面需要开启fileinfo扩展，否则会报错，报错内容大概为：Call to undefined function finfo_open()
[/hong]
