Version: (using KDE KDE 3.4.1) Installed from: Gentoo Packages OS: Linux I would like to propose a new plugin that is very effective for removing stripes from slide/negative/positive scans, as well as subtle de-noising without loosing detail. The technique is described here: http://www.no-hype.com/articles/denoise.html For example, for removing vertical-only noise (like horizontal scanner stripes) from the image, you do this in the GIMP: 1. Duplicate the image to _two_ new layers and place the duplicates on top of the original. 2. Use the 'overlay' effect on the two top layers 3. Use the Gaussian Blur (IIR) effect on the topmost layer. Typical radius is 30 pixels 4. Use the Gaussian Blur (IIR) effect on the middle layer, use a horizontal radius of 30 pixels and a vertical radius of 1. 5. Invert the colors of the middle layer 7. Merge all layers into one. 8. Repeat the process one or more times I always use the GIMP to use this method for removing scan-stripes and noise, then I switch to DigiKam for re-focussing (amazing plugin by the way!). The results of the combination of destripe/denoise in GIMP and re-focus in DigiKam are really impressive. It would be very nice to implement this manual destripe/denoise method in a DigiKam image editor plugin. Then I can denoise my pictures entirely using DigiKam.
Try my new Noise Reduction tool from svn trunk branch (future 0.9.0 release), and give me a feedback. There is a preview here : http://www.digikam.org/?q=node/79 Gilles Caulier
Impressive method for reducing stripes! I have another wish for future noise reduction tools: Digital camera noise: Effective commertial noise reduction tools seperate lightness noise and color noise. The lightness noise is fine grained, but the color noise has large flakes. Color noise usually can get blurred far more than lightness noise, that makes it very effective to seperate both and apply different blurring values. Filtering is possible with gaussian blurring, filtering of frequencies or GREYCstoration, I don't know what works best. I use the shareware of NeatImage at the moment, look at the site: http://www.neatimage.com/ It would also be cool to implement that method into digicam.
Dik, This entry still valid using Noise Reduction plugin from 0.9.3 release ? Gilles Caulier
Bringing this up again... is this still valid?
Well, I have access to a high quality slide scanner now, so I no longer need a stripe noise killer. Maybe this is too much of a special purpose filter for DigiKam anyway. Close wish?
Dik, Yes, and we have already 2 tools to reduce noise in editor. Gilles