Форум

   $arFile = CFile::GetFileArray($arEl["DETAIL_PICTURE"]);
      $arFile =CFile::ResizeImage(
          $arFile, 
          array(
           "width" => 264, 
           "height" => 351 
          ),
          BX_RESIZE_IMAGE_PROPORTIONAL 
        );
       
       $fileId = CFile::SaveFile($arFile, "iblock");
    
      $el->Update(intval($arEl["ID"]),array("PREVIEW_PICTURE"=>array("del"=>"Y")),false,true,true,true);
      
      $el->Update(intval($arEl["ID"]),array("PREVIEW_PICTURE"=>$fileId),false,true,true,true);