php – WordPress – 上传的模糊图像

我没有想象力,所以你必须自己尝试这些功能,但是你有正确的过程,你只需要更新文件名并在下面的数组中输入. PS不会在过滤器中输出任何内容！

function custom_img_size(){
    add_image_size( 'background-image-blurred',true );
}

add_action( 'after_setup_theme','custom_img_size' );


add_filter('wp_generate_attachment_metadata','force_add_size',100);
function force_add_size( $metadata ) {

   if(!isset($metadata['sizes']['background-image-blurred'])){
        //not set so initiate our custom size...
        //I dont have imagick installed so just use your functions here to duplicate
        //note original file = $filename update the $newfilename below...
        //sample resize code ...
        $upload_dir = wp_upload_dir();
        $filename= $upload_dir['basedir'].'/'.$metadata['file'];
        $extension = strtolower(strrchr($metadata['file'],'.'));
        $newfilename= str_replace($extension,'-1200x1080',$filename).$extension;

        copy($filename,$newfilename );
        //end sample resize code.....



        $filetype= 'image/jpeg';
        $metadata['sizes']['background-image-blurred']= array(
            "file"=> $newfilename,"width"=> 1920,"height"=> 1080,"mime-type"=> $filetype 
        );

   }


   return $metadata;

}

更新

>这是为了只捕捉你现有的过滤器失败创建模糊的自定义大小,否则它什么都不做.您仍然应该包含原始过滤器.您可能在原始代码中有问题：您正在删除过滤器中的原始文件,这将导致问题,因为有一个名为’_wp_attached_file’的postmeta字段将需要更新.我已经在这里添加了一个注释.
>过滤器在保存之前捕获元数据,所以任何更改也将在返回$元数据后保存.如果你看源码：https://core.trac.wordpress.org/browser/tags/3.8.1/src/wp-admin/includes/image.php#L72这里你可以看到它的工作原理.我也确认使用wp4.3
>我尝试在下面插入您需要的想像功能.我没有测试,因为我实际上没有安装在任何地方. (imagemagick实际上是一个很棒的开源程序,但服务器密集).尝试此功能代替上述功能：

add_filter('wp_generate_attachment_metadata',100,2);

function force_add_size( $metadata,$id ){

    $upload_dir = wp_upload_dir();
    $filename= $upload_dir['basedir'].'/'.$metadata['file'];
    $extension = strtolower(strrchr($metadata['file'],'.'));
    $newfilename= str_replace($extension,'-blurred',$filename).$extension;

    $image_resource = new Imagick( $filename);
    $image_resource->resizeImage(1920,Imagick::FILTER_LANCZOS,.3);
    $image_resource->writeImage( $newfilename );
    //http://www.dylanbeattie.net/magick/filters/result.html

    unlink( $filename );//delete original image altogether ---> you might want to update the post meta on this '_wp_attached_file',you can actually get the attachment id from the filter,i have added it above. It would be best to have a actual image url in there! something like $sfile= str_replace($upload_dir['basedir'],'',$newfilename); update_post_meta($id,'_wp_attached_file',$sfile );



    switch($extension){
        case '.jpg':
        case '.jpeg':
            $type = 'image/jpeg';
            break;
        case '.gif':
            $type = 'image/gif';
            break;
        case '.png':
            $type = 'image/png';
            break;
        default:
            $type = 'image/jpeg'; // you might want a conditional to check its actually a image...imagick will do this for you as well....it shouldnt get this far if not a image.
            break;
    } 

    $metadata['sizes']['background-image-blurred']= array(
        "file"=> $newfilename,//your custom image size,has to be this! you could get the global var and check for sizes but its this size in particular we want? 
        "height"=> 1080,"mime-type"=> $type 
    );

    return $metadata;
}

更新
为了防止图像展开较小的图像,用这个代替想象代码.

$upload_dir = wp_upload_dir();
$filename= $upload_dir['basedir'].'/'.$metadata['file'];
$extension = strtolower(strrchr($metadata['file'],'.'));
$newfilename= str_replace($extension,$filename).$extension;

$image_resource = new Imagick( $filename);


if($image_resource->getImageWidth() <= 1920 || $image_resource->getImageHeight() > <= 1020) {
    return $metadata;
}

$image_resource->resizeImage(1920,.3);
$image_resource->writeImage( $newfilename );
//http://www.dylanbeattie.net/magick/filters/result.html