Overview

MuPDF can optionally make use of a color management engine to offer a fully color managed workflow.

Its use of the engine is encapsulated within the fz_cmm_engine structure. Currently we provide an implementation of this structure using a modified version of LCMS2 (known as LCMS2MT), but systems with other CMM engines in already can use those instead by reimplementing the functions therein.

By default, on start-up, MuPDF has no color management engine enabled. This keeps the library size down (and performance up!) for people who do not wish to use it.

The relevant functions are:

$\begin{lstlisting} /* fz_set_cmm_engine: Set the color management engine to be... ...to a single thread. */ extern fz_cmm_engine fz_cmm_engine_lcms; \end{lstlisting}$

Thus to enable the color managed workflow using LCMS, call:

$\begin{lstlisting} fz_set_cmm_engine(ctx, &fz_cmm_engine_lcms); \end{lstlisting}$

It is best to do this immediately after creating the base context.

It is possible to switch between ICC and non-ICC workflows in the same instance of MuPDF (and even to use the two simultaneously). It is, however, not generally possible to swap a given context once operations on that context have started. This is because any outstanding fz_colorspaces (such as those found within the store) will still refer to the wrong color management implementation!