How to enlarge figure by animate

Question

Objective: First, I put a picture (named test.png) in a circle (made by TikZ). Then, I want to get an animated effect to enlarge the whole figure by controlling the value of the option scale.

The final typeset does not show enlarging figures, however.

Code:

\documentclass{article}
\usepackage{animate,calc,tikz,graphicx}

\newcounter{animate}
\newcommand\test[1]{
  \setcounter{animate}{10 * \real{#1}}
  \begin{animateinline}[autoplay]{12}
    \multiframe{\theanimate}{Rscale=0.1+0.1}{
      \begin{tikzpicture}[transform shape]
        \path
        [path picture={\node at (0,0)
           {\includegraphics[width=2.1cm]{test.png}};},
         draw=orange,thick,scale=\Rscale,
        ] 
        (0,0) circle (1cm);
      \end{tikzpicture}
    }
  \end{animateinline}
}

\begin{document}
\test{3.55}
\end{document}

Answer 1

From my understanding, \multiframe frames value cannot be a real number, it's must be a integral. And your animation graphic need some space for the picture getting bigger. So you need set a enough size of empty background for the picture (consider the final size of the picture). I draw frame for the background just for showing the effect. Following is a working example.

\documentclass{article}
\usepackage[margin=2cm,showframe]{geometry}
\usepackage{lipsum}
\usepackage{animate,calc,tikz,graphicx}

\newcounter{animate}
\newcommand\test[1]{%
\par{\noindent\centering\setcounter{animate}{10 * #1}%
\begin{animateinline}[poster=last,autoplay,loop]{20}
    \multiframe{\theanimate}{Rscale=0.1+0.1}{
      \begin{tikzpicture}
        \path [draw] (-4,-4) rectangle (4,4);
        \node[circle,draw=orange,thick,scale=\Rscale] at (0,0){\includegraphics[width=1cm]{test.png}};
      \end{tikzpicture}
    }
\end{animateinline}\par}
}

\begin{document}
\lipsum[1]
\test{4}
\lipsum[2]
\end{document}

Answer 2

It is not clear, how you like to change image size. Just image in the fixed circle size?

\documentclass{article}
\usepackage{tikz}
\usepackage{animate}

\begin{document}
    \begin{animateinline}[poster=first, controls, autoplay,
                          ]{10}
\multiframe{12}{Rscale=1+1}%
{
\begin{tikzpicture}
    \path[path picture={\node at (0,0)
           {\includegraphics[scale=\Rscale]{example-image-duck}};},
          draw=orange,thick,
         ]  (0,0) circle (22mm);
\end{tikzpicture}
}
  \end{animateinline}
\end{document}