Due to its interferometric nature, digital holographic microscopy (DHM) provides access to the complex wavefront and holds the capability of imaging simultaneously amplitude and quantitative phase. Thus, DHM is an attractive research tool in many fields of biological research and an interesting alternative to classical fluorescence microscopy. For such intensitybased microscopy, however super-resolution methods are available. Consequently, we propose a method to improve the resolution of coherent microscopy systems, too.