\documentclass[aspectratio=1610,compress]{beamer}
\frenchspacing
\usepackage[italian]{babel}
\usepackage[latin1]{inputenc}
\usepackage{xspace,colortbl}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{amsfonts}
\usefonttheme[onlymath]{serif}
\usetheme[]{Madrid}
\useoutertheme[footline=authortitle, subsection=false]{miniframes}
\setbeamertemplate{blocks}[rounded][shadow=true]
\setbeamercovered{transparent}
\newcommand\BackgroundPicture[1]{%
\setbeamertemplate{background}{%
\parbox[c][\paperheight]{\paperwidth}{%
\hfill \vfill \centering
\includegraphics[height=.9\paperheight]{#1}
\hfill \vfill
}}}
\title[Project]{}
\institute[Institute]{Institute Long}
\defbeamertemplate*{footline}{mytheme}
{
\leavevmode%
\hbox{%
\begin{beamercolorbox}[wd=.3\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%
\usebeamerfont{author in head/foot}~\insertshorttitle
\end{beamercolorbox}%
\begin{beamercolorbox}[wd=.7\paperwidth,ht=2.25ex,dp=1ex,right]{date in head/foot}%
\usebeamerfont{date in head/foot}\insertshortinstitute{}\hspace*{20em}
\insertframenumber{} / \inserttotalframenumber\hspace*{2ex}
\end{beamercolorbox}}%
\vskip0pt%
}
\usebeamertemplate{mytheme}