filters for The GIMP, using math models filter colors

• try out formulas plugin in the prototype directory (same install rocedure as below)
• download our filters in the bin directory
• in simplefilters : basic filters that take the RGB code and transform it with one function. Might not be very efficient, TODO is to rewrite them in the style of the ones in the rowfilter directory
• in rowfilter : filters that work with the entire row of pixels. More efficient (less calls to get_pixel function)

HOW TO INSTALL the filters without gimptool-2.0 : simply copy the files from the bin/ directory into your own gimp plugin directory : It shall be

• on MACOSX /Users/YOURUSERNAME/.gimp-2.8/plug-ins/
• on linux /home/YOURUSERNAME/.gimp-2.6/plug-ins/

then start the gimp, and the filter should be inside the menu plugin->math, and appear in the about box.

To remove the plugins, delete the files from the plug-ins directory above mentionned.

==> exponential.c <==

RESULT = the exponential color code (255*(-1 +exp(code))/(-1 +exp(255)) )

==> sinuss.c <==

RESULT = put the sinus color code (255sin(2PIcode/255))

==> cosinuss.c <==

RESULT = put the cosinus color code (255cos(2PIcode/255))

==> symmetric.c <==

RESULT = the color code symmetric with regards to the point: (128,128,128,128)

==> symmetricrange.c <==

RESULT the color code symmetric with regards to the range of the image the code should stay in the same range R G B A but the values are swaped min to max

*** NOT the same as a NEGATIVE filter ***

==> sinus-hue & cosinus-hue <==

get the sinus (cosinus) of the HUE color component :

• pass from RGB to HSB (vector : Hue,S,B)
• then apply new_Hue = (180* (1+sin(2PIHue/360))) or (180 (1+cos(2PI*Hue/360)))
• then new_Hue,S,B in HSB to RGB.

in ITALIAN -- filtri per The GIMP, modificano il colore sulla base di modeli matematici

i plugin per GIMP si inseriscono nel menu plugin->math Usano un modello già aposto (http://developer.gimp.org/writing-a-plug-in/1/index.html) part II,

purpose: trasformare i colori di ogni pixel secondo un processo matematico, una formula ad esempio 256sinus(2PIcolor/256), compile: gimptool-2.0 su linux

. Gimp a anche possibilità di fare dei Batch, e automatizzare tutto il processo (apri file, applica fitro, salva newfile) che permette di fare il test sensa passare dal GUI. test per adesso : con sinus, cosinus, log, exp, symetric che sono direttamente usabili.

domanda retorica : come integrare un processo iterativo tipo fratale ? e quale fratale ?

ad esempio Lyapunov http://plus.maths.org/content/extracting-beauty-chaos.

E fattibile anche in Ruby con RMagick o ImageRuby (independant) http://tario-project.blogspot.it/2011/04/released-imageruby-flexible-ruby-image.html --------------------------------------- troppo vecchio