David Esp Video Technical Blog

There exist Wavelet-based filters/plugins for Gimp.

• I wanted such filters for Gimp since experiencing good results with wavelet-based detail-enhancement in RegiStax.
  • I was not alone in this desire: http://stargazerslounge.com/topic/124475-wavelet-sharpening-which-one/
• Others at http://www.flickr.com/groups/gimpusers/discuss/72157623877664801/ seem enthusiastic also.
  • One poster’s impression, from nearly three years ago: <<
    Wavelet Sharpen seems better than Photoshop Smart Sharpen, which was the best sharpening tool I had used. (Never tried PhotoKit.)
    In this comparison, the GIMP image has sharper Yucca plants, it is easier to read the logo letters on the green shirt, and the file size is smaller than from Photoshop.
    >>
  • But it is of course possible that Photoshop’s “Smart Sharpen” may have improved since then.
    • Indeed http://6sightreport.com/2010/04/26/wavelets-sharpen-photoshop-images/:
      • Technology for “Edge Avoiding Wavelets” is in the improved new Sharpen Tool in Photoshop CS5 and its ‘Protect Detail’ feature

Simplest to use are the Wavelet Sharpen and Wavelet Denoise filters.  Nevertheless, the following text-tutorial for Wavelet Decompose filter, provides a useful grounding in the pragmatocs of what wavelets are (in our image-editing-in-Gimp context).

• The following tutorial shows examples of wavelet layers, and how they can be combined:
  • http://blog.patdavid.net/2011/12/getting-around-in-gimp-skin-retouching.html
• The following presentation (as a sequence of webpages) give some gentle technical background to wavelets in image-processing:
  • http://cas.ensmp.fr/~chaplais/Photoshop_Wavelet_Workout/index.html

I stumbled upon the following Forum thread, including a download (Zip file) of a number of filters compatible with Gimp v2.8, including Wavelet-based ones.  Here’s the link:

• http://www.gimpchat.com/viewtopic.php?f=9&t=4216
  • Download is 20 mb and includes 270 plugins for Gimp-2.8
  • (It also includes downloads/advice for MathMap, but ignore those; if you want MathMap then see my earlier post)

Once installed, the Wavelet filters are available in Gimp’s Menu:

• Wavelet Sharpen in [Filters > Enhance]
• Wavelet Denoise in [Filters > Enhance]
• Wavelet Decompose (into Gimp Layers) in [Filters > Generic]

This entry was posted on Saturday, January 19th, 2013 at 01:41 and is filed under Gimp. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.