CLAHE update, speed up
Posted by
Stephan Saalfeld on
Aug 12, 2010; 7:21pm
URL: http://imagej.273.s1.nabble.com/CLAHE-update-speed-up-tp3687263.html
Dear friends of ImageJ/Fiji,
we implemented the fast version of the Contrast Limited Adaptive
Histogram Equalization
http://pacific.mpi-cbg.de/wiki/index.php/Enhance_Local_Contrast_(CLAHE)
>From user perspective, the only difference to the old implementation is
a new checkbox in the parameter dialog to toggle between fast and slow
version. Default is fast. In the faster implementation, the local
contrast adjustment is not calculated for each single pixel
independently but for adjacent cells of the given block-size only. The
transfer function for locations in between is interpolated. This is the
approach as described in the original publication for close to real time
video enhancement.
You will notice, that the result is not exactly the same as in the exact
per-pixel evaluation but relatively close. It is convenient to find
appropriate parameters with the fast version and finally apply it with
the accurate version.
The update is available through the Fiji-Updater
http://pacific.mpi-cbg.de/wiki/index.php/Update_Fijior as a standalone jar for ImageJ's plugins folder
http://fly.mpi-cbg.de/saalfeld/download/clahe_.jarSources are published under GPL2 and tracked in the mpicbg git
repository
http://pacific.mpi-cbg.de/cgi-bin/gitweb.cgi?p=mpicbg.git;a=tree;f=mpicbg/ij/claheBest regards,
Stephan