Enblend-Enfuse are open source console application created by Andrew Mihal and mostly maintained by Hugin developers.

It consists of Enblend, an image blending tool useful for creating panoramas, and Enfuse, an exposure fusion (HDR merging) and focus stacking tool that combines the depth of field and dynamic range from multiple images of the same scene (bracketing).

[3] Enfuse uses the Mertens-Kautz-Van Reeth (MKVr) approach to exposure fusion, which does not require reconstructing an HDR intermediate.

The MKVr approach involves blending images by quality estimates based on contrast, saturation, and well-exposedness.

For example, a basic focus stack is combined in Enfuse by having the quality estimator only consider contrast, and by having the MKVr blending only use the single best-scoring pixel.