I want to convert cursor data to String so i can insert it in MySQL data base

Im facing an issue! i have been trying to insert data that is fetched from mySQL DB via matlab using cursor, to another table in MySQL after image processing. but facing these errors:

Error using imread>parse_inputs (line 458) The filename or url argument must be a string.

Error in imread (line 317) [filename, fmt_s, extraArgs] = parse_inputs(varargin{:});

Error in db1 (line 17) d = imread(curs.data(:));

I have tried to convert cursor to string but have failed so far..

Here is my code:

function [rr] = db1()
sqlquery = 'select Disease_Image from disease_image where Processed is NULL';
conn = database('e_gardener','root','',...
'Vendor','MySQL',...

'Server','localhost');
curs = exec(conn,sqlquery);

% Initialize rowlimit
rowlimit = 1

% Check for more data. Retrieve and display all data.
while ~strcmp(curs.Data,'No Data')
  curs = fetch(curs,rowlimit);

  curs.Data(:)

    d = imread(num2str(curs.data(:)));

   rr = Detect(d);
    datainsert(conn,'photo_maths',{'Result'},{rr});

end
end