Failed to read the file imagick exception

i am trying to convert PDF to image but it shows me "Failed to read the file imagick exception" error.i am already installed ghost script and imagick. both are showing me in Apache $path. but still this issue is coming.please help me.

Thank you

my code is like this

if(!empty($society_member_details['user_society_member_id_proof'])){
$id_proof_array = explode(".",$society_member_details['user_society_member_id_proof']);
                if (end($id_proof_array) == "pdf"){
                    $image = new Imagick();
                    $image->pingImage(base_url().'/uploads/users/'.$this->session->user_id.'/society_forms/id_proof/'.$society_member_details['user_society_member_id_proof']);
                    $page_count = $image->getNumberImages();
                    
                    for ($i=0; $i < $page_count; $i++){
                        $img = new imagick(APPPATH.'../uploads/users/'.$this->session->user_id.'/society_forms/id_proof/'.$society_member_details['user_society_member_id_proof']);

                        //set new format
                        $img->setImageFormat('jpg');

                        $image_name = str_replace(".pdf","",$society_member_details['user_society_member_id_proof']).$i;
                        //save image file
                        $img->writeImage(APPPATH.'../uploads/users/'.$this->session->user_id.'/society_forms/id_proof/'.$image_name.".jpg");
                        chmod(APPPATH.'../uploads/users/'.$this->session->user_id.'/society_forms/id_proof/'.$image_name.".jpg", 0777);
                        $id_card_data .= '<img style="max-width:600px;max-height:600px;" src="'.base_url().'uploads/users/'.$this->session->user_id.'/society_forms/id_proof/'.$image_name.'.jpg" /><br/>';
                    }
                }

 

Error is in this line

$image->pingImage(base_url().'/uploads/users/'.$this->session->user_id.'/society_forms/id_proof/'.$society_member_details['user_society_member_id_proof']);