Question
I am using a background image that has a black border of equal thickness all the way around it (which I created and saved as an .eps file).
In my LaTeX document, however, I cannot seem to get the border to appear in equal thickness all the way around the image. How can I solve this?
Minimum Working Example
\documentclass[landscape,a0b,final]{a0poster}
\usepackage{epsfig}
\usepackage{pstricks,pst-grad}
\newcommand{\background}[3]{
\newrgbcolor{cgradbegin}{#1}
\newrgbcolor{cgradend}{#2}
\psframe[fillstyle=gradient,gradend=cgradend,
gradbegin=cgradbegin,gradmidpoint=#3](0.,0.)(1.\textwidth,-1.\textheight)}
\newenvironment{poster}{
\begin{center}
\begin{minipage}[c]{0.95\textwidth}}{
\end{minipage}
\end{center}}
\usepackage{eso-pic}
\newcommand\BackgroundPic{
\put(10,-50){
\parbox[b][\paperheight]{\paperwidth}{%
\vfill
\centering
\includegraphics[width=\paperwidth,height=\paperheight,
keepaspectratio]{TheSun2.eps}\vfill}}}
\begin{document}
\AddToShipoutPicture{\BackgroundPic}
\begin{poster}
\end{poster}
\end{document}
Note
My image is a .eps file - I'm not sure how to upload this (or whether it's necessary).
My background image is a photo with a black border round it. I took the photo and put it in Inkscape, then made a black border round it, with equal thickness round each side. I specified the thickness mathematically. In Inkscape, the border looks uniform. In Texmaker, it is obvious that the border is non-uniform (with the above MWE at 100% zoom):
