WordPress 上传图片自动压缩教程

在主题functions.php函数文件里添加即可，图片只有jpg格式适合压缩。

function wt_handle_upload_callback($data)
{
    $image_quality = 60; // 压缩比例 0-100选择
    $file_path = $data['file'];
    $image = false;

     switch ( $data['type'] ) {
         case 'image/jpeg': {
             $image = imagecreatefromjpeg( $file_path );
             imagejpeg( $image, $file_path, $image_quality );
             break;
         }

         case 'image/png': {
             //$image = imagecreatefrompng( $file_path );
             //imagepng( $image, $file_path, $image_quality);
             //png不支持压缩，可以使用webp代替，但是ie浏览器不支持webp文件格式
             //imagewebp( $image, $file_path, $image_quality);
             break;
         }

         case 'image/gif': {
             // Nothing to do here since imagegif doesn't have an 'image quality' option
             break;
         }
     }

    return $data;
}

add_filter('wp_handle_upload', 'wt_handle_upload_callback');