  \textbf{FlexBox} is a flexible MATLAB toolbox for finite dimensional convex
variational problems in image processing and beyond. Such problems often
consist of non-differentiable parts and involve linear operators. The toolbox
uses a primal-dual scheme to avoid (computationally) inefficient operator
inversion and to get reliable error estimates. From the user-side,
\textbf{FlexBox} expects the primal formulation of the problem, automatically
decouples operators and dualizes the problem. For large-scale problems,
\textbf{FlexBox} also comes with a \cpp-module, which can be used stand-alone
or together with MATLAB via MEX-interfaces. Besides various pre-implemented
data-fidelities and regularization-terms, \textbf{FlexBox} is able to handle
arbitrary operators while being easily extendable, due to its object-oriented
design. The toolbox is available at
\href{http://www.flexbox.im}{http://www.flexbox.im}
