Version: (using KDE 4.3.1) OS: Linux Installed from: SuSE RPMs Purple fringing is a well known and awful effect which often affects some lenses. It occurs mainly when taking highly contrasted images (dark subjects against strong background highlights) with wide-angle lenses and large apertures. A digiKam tool for image defringing would be very interesting, and it doesn't seem too complicated to implement. An example algorithm can be found at http://tams-www.informatik.uni-hamburg.de/applets/hades/webdemos/00-intro/02-imageprocessing/purple.html Here a simple algorithm written in Java is run under University of Hamburg's Hades simulator. The effect can be clearly seen in the output vs input images. However, as also stated in the page above, it would be desirable to combine the defringing algorithm with edge detection to avoid artifacts in areas with genuine blue shades.
Hi Francisco and happy new year, Please take a look in GMic Qt plugin for digiKam image editor to see if this kind of tool do not exists yet. Best regards Gilles Caulier
For all digiKam Image Editor advanced improvements, we will delegate this the Gmic-Qt plugin which is stable enough everywhere to be used in production. It include more than 400 filters to use by photographers. https://i.imgur.com/OFerL8H.png