On Sat, 13 Jun 2009 16:16:35 -0500 Chris Gentle <[email protected]> wrote:
| Hi. I need some help using the -modulate option. I use modulate to | "clean up" some dirty looking scans that my old scanner produces. | After I upgraded to Ubuntu Jaunty (imagemagick version 6.4.5) I | noticed that the behavior of -modulate changed. The command I'm using | is basically this: | | convert original.tiff -flatten -depth 8 -modulate 140 new.jpg | | Imagemagick version 6.3.7 in Ubuntu Intrepid produced the following: | | http://home.hiwaay.net/~gentlec/20090613-160502.jpg | | After upgrading to 6.4.5 in Jaunty I now get this: | | http://home.hiwaay.net/~gentlec/20090613-160105.jpg | | I'm definitely not an imagemagick expert. If the -modulate command | has changed, is there any way for me to reproduce what it was doing in | earlier versions? | Change log reports... 2008-04-20 6.4.0-10 Chris Madison <madison...@hotma...> * Default to HSL colorspace when modulating (reference http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=11073). Basically it now used HSL colorspace rather than HSB colorspace which means that images will be brightened toward white rather than toward black. But it is not without its own problems, as was later found in the forum discussion http://www.imagemagick.org/discourse-server/viewtopic.php?t=12640 Your damned with HSB and your damned with HSL! If you want to modulate with HSB, see IM Examples http://www.imagemagick.org/Usage/color/#modulate Specifically convert original.tif -colorspace HSB \ -channel B -evaluate multiply 1.4 +channel \ -colorspace RGB new.jpg Which is what modulate basically does for brightness. Perhaps we should arrange for some switch/flag/option to allow the user to select to modulate in HSL or HSB colorspace, seeing BOTH colorspaces has some negative situations. Anthony Thyssen ( System Programmer ) <[email protected]> ----------------------------------------------------------------------------- Cartoon Law III : Any body passing through solid matter will leave a perforation conforming to its perimeter. ----------------------------------------------------------------------------- Anthony's Home is his Castle http://www.cit.gu.edu.au/~anthony/ _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
