% -*- coding: utf-8 -*-
%%kompilacja XeLaTeX
\documentclass{report}
\usepackage{polski}
\usepackage{fontspec}
\usepackage{graphicx, color}
\usepackage{url}
\usepackage{caption}
\captionsetup{justification=raggedright,singlelinecheck=false}
\usepackage{subfig}
\usepackage{xunicode}
\usepackage{xltxtra}
\pagestyle{empty}
%%
\def\source#1{\par \begin{flushleft}\small \SourceName:~#1\end{flushleft}}
\def\SourceName{\emph{\'Zr\'od{\l}o}}
%%
\makeatletter
\g@addto@macro{\UrlBreaks}{\UrlOrds}
\makeatother
%
\begin{document}
%%
\begin{figure}[!hbtp]
\centering
\includegraphics[width=0.75\linewidth]{hors15.png}
\setcaptionwidth{0.85\linewidth}
\caption{Główny podpis pod rysunkiem, wyrównanie do lewej}\label{logotyp2}
\vspace*{-.5mm}
\begin{minipage}[t]{0.85\linewidth}
\source{opracowanie własne na podstawie \url{http://strona.źródłowa.pl}}
\end{minipage}
\end{figure}
%%
\end{document}