Hey Georg, I quickly tried you patch on some images. it does a decent job on darker images, but can ruins everything on a correctly exposed image, saturating and creating too much highlights.
there's probably something wrong in the implementation as the histogram is indeed flat, except for a peak at the right... could you please open an enhancement bug with your patch attached, so it doesn't get lost ? regards s On Tue, 2008-04-22 at 19:20 +0200, Georg Leugner wrote: > Am Dienstag, den 22.04.2008, 14:05 +0200 schrieb Stephane Delcroix: > > On Mon, 2008-04-21 at 16:32 +0200, Georg Leugner wrote: > > > So it has been done... I implemented RGB to HSV, or be precise HSI, at > > > my own, because I didn't get the lcms stuff... > > > I'm a little bit disappointed, because the result is in gray is more > > > impressive, but I have some more ideas. > > > > > > So let's come to the good things: > > > * the result is most of the time nicer than the "Histogram Equalizer" in > > > gthumb and that is the same algorithm. > > nicer with the same algorithm ? we're is the magic ? > > I didn't look into their source code. But I think they are using the HSV > color space and I implemented it in HSI. I'm working with the I > component ((r+g+b)/3 ), which is more exact than the V (max (r,g,b)). > > > > > > * the result is in dark images most of the time nicer than 'color > > > improve' from f-spot > > > > > > Now to the ugly stuff: > > > * I am maybe not too objective about the quality of output image > > am ok to try that on some of mines > > > * noise and image can be seen better > > as expected > > > * the performance could be really improved. Help wanted. > > doing the conversion in managed code (c#) is expensive (due to the > > additional checks), rewriting the conversions in C, or better with > > mmx/sse will probably kick ass, but that could be done later... > > > * the conversion from RGB to HSI and back again manipulates the image > > > due to rounding faults. More Help wanted... > > as expected. as long as the diff is minimal (1 bit per channel) it's ok > > > > > > I put the code into src/Filters (that's not a good place for > > > HSIImage.cs, i know...). > > > > could you please also send the patch to f-spot you used to test the > > feature (even if you think it's ugly (like reusing the autocolor > > button :) )) > > Why did you know that? I used even more ugly the tilt filter to test my > filter and color filter together. > > > > > regards > > > > s > > > > > > Regards, > > > > > > georg > > > > > > > > > Am Montag, den 14.04.2008, 10:58 -0500 schrieb Larry Ewing: > > > > The interactive color adjustment dialog does a lot of this sort of > > > > transform but it does it via an adjustment profile that it creates on > > > > the fly. It may be hard to follow the code because we use lcms and the > > > > actual image color profile to convert to luminance space, adjust, then > > > > convert back again in single pass. That code could be adapted to convert > > > > to a colorspace of your choosing which could then be used collect the > > > > statistics you want to create an adjustment back to rgb. > > > > > > > > If you would like try that direction I can help walk you through the > > > > darker corners of the code. Otherwise as Stephane points our there > > > > isn't much existing infrastructure to help you out at the moment. > > > > > > > > --Larry > > > > > > > > On Mon, 2008-04-14 at 14:37 +0200, Stephane Delcroix wrote: > > > > > Hey, > > > > > > > > > > 1. no, there's no doc but the code itself... > > > > > 2. AFAIK, (Gdk)pixbuf doesn't support HSV. so "converting a RGB pixbuf > > > > > to HSV" doesn't make a lot of sense > > > > > so, you'll probably have to do the RGB->HSV conversion (and back) > > > > > yourself, but you might find some converter already available on the > > > > > web. My .02€ tip: don't do that in managed code, it'll be way too > > > > > slow. > > > > > > > > > > s > > > > > > > > > > On Sun, 2008-04-13 at 19:59 +0200, Georg Leugner wrote: > > > > > > Hallo, > > > > > > > > > > > > I'm currently coding on the one click contrast filter like picassa > > > > > > has. > > > > > > But I need some information: > > > > > > 1. First and most important. Is there somewhere hidden more > > > > > > documentation than on the get involved page? > > > > > > 2. I need to convert a RGB pixbuf to HSV. I couldn't find a method > > > > > > which > > > > > > does that, but i found some methods using hue, saturation... Do I > > > > > > miss > > > > > > something? > > > > > > > > > > > > Kind regards, > > > > > > > > > > > > georg > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > F-spot-list mailing list > > > > > > [email protected] > > > > > > http://mail.gnome.org/mailman/listinfo/f-spot-list > > > > > > > > > > > > > > > > _______________________________________________ > > > > > F-spot-list mailing list > > > > > [email protected] > > > > > http://mail.gnome.org/mailman/listinfo/f-spot-list _______________________________________________ F-spot-list mailing list [email protected] http://mail.gnome.org/mailman/listinfo/f-spot-list
