PanoTools:
Re: Blending Large Overlaps
Yuval Levy 2006-Jun-12 09:49:16
Geraldine Joffre wrote:
> Try those other tonemapping algorithms (with Artizen HDR for instance)
it crashed my computer.
> I don't have the impression that you tried the most used exposure
> blending function of Photomatix named "H&S - Auto". People like it
> precisely because it gives results that look natural.
I do not know about Jeffrey, but I have found that your "H&S details
auto" is exactly what I need most of the times. At about 8 EV brackets
the result becomes a little bit too dull for my taste (but then all of
this tonemapping is an extremely subjective topic) and in that case I go
with HDR and tonemapping.
Tonemapping with Photomatix provides enough variation through the
sliders and settings and I get immediate feedback on how the picture
will look like. I can slide/set until the halos are not disturbing me.
The main advantage I found of tonemapping vs. exposure blending is that
it can give a spin to the panoramas. I recently shot a rainbow on a lake
at sunset and the added tonemapping contrast makes it awesome and surreal.
> Moreover, it is
> more convenient for panographers than tonemapping because it does not
> require to stitch differently exposed panos. You only need to stitch
> the images resulting from combining the bracketed shots in Photomatix.
I will have to try the process you describe above. I admit a certain
reluctance because my guts feeling tells me that the separately combined
individual images will have different exposure and color balance? You
might push me to try it if you add chromatic aberration and vignetting
correction to your RAW conversion. Then I'd feed the RAWS into
Photomatix and forget about Adobe RAW converter.
Which brings me to another question posted by Roger on this thread: the
ghosting people and other moving objects.
In some panos I find the ghosts of people moving between shots to be
part of the artwork - e.g. when shooting on a busy pedestrian area.
The technique to avoid moving objects has become very simple since the
latest PTgui can take alpha-transparent TIFFs as an input. I know you
are using another software than Photoshop, Roger, but I am confident
that you can try my process below also with that software:
* open tiff file of individual shot
* switch from layers to channels
* click on little icon to add an alpha transparency layer
* set colors to foreground white background black
* fill the whole area in white
* make the RGB channels visible again
* take the eraser tool in block mode and remove unwanted details - in
doing so pay attention that you have overlap from another input shot. I
always open two adjacent shots together to decide what area of which I
want to erase.
* save the tiffs with alpha channels and feed into PTgui.
* repeat if this did not yield the expected result.
Then, to backup the whole project, since I do not save the (heavy)
TIFFs, but only the RAWs, the XMPs (Photoshop's conversion data) and the
PTSs (Ptgui's project):
* rightclick on alpha layer and duplicate channel to a new document
* save for later reference as photoshop XXXXalpha.psd where XXXX is the
number/name of the image
This way I optimize storage (all the images and information needed to
re-create the pano are stored) and replicability (I can replay any step
in the process).
Yuv
>
>
>
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
------------------------ Yahoo! Groups Sponsor --------------------~-->
Home is just a click away. Make Yahoo! your home page now.
http://us.click.yahoo.com/DHchtC/3FxNAA/yQLSAA/.Cr1lB/TM
--------------------------------------------------------------------~->
<*> PanoTools.Info Wiki
http://wiki.panotools.org
<*> PanoTools.Info List Archives
http://lists.panotools.info/pipermail/ptml/
<*> PanoTools List Reader @ GMane:
http://news.gmane.org/gmane.comp.graphics.panotools
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/PanoTools/
<*> To unsubscribe from this group, send an email to:
#removed#
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/