[ Thanks to Dmitri
Popov for this link. ]
“digiKam offers several features that can improve
photos containing under- or overexposed areas. For example, the
Exposure Blending tool lets you merge multiple shots with different
exposures into one perfectly exposed photo. But what if you have
just a single image? In this case, you might want to give the Local
Contrast feature a try. It’s based on the LDR Tonemapping utility
which is designed to improve the dynamic range of the photo by
reducing its global contrast and increasing the local contrast. It
does so by generating a desaturated and blurred version of the
photo. It then combines the RGB channels of the original photo with
the desaturated blurred image using either the Linear or Power
function. Sounds complicated? Don’t worry, the Local Contrast tool
is rather straightforward to use, so you don’t have to understand
all its intricacies in order to achieve pleasing
results.”