[Kstars-devel] questions re: gathering images

[Luciano Montanaro]

On Wednesday 06 December 2006 17:26, Jason Harris wrote:
> Hi Glenn,
>
> On Tuesday 05 December 2006 19:46, Glenn Becker wrote:
> > > Alternatively, we can put this
> > > information in a tooltip.  What do you think?
> >
> > Personally I like the tooltip. In my head anyway it is less intrusive.
>
> We'll try it as a tooltip first, we can always switch if it doesn't work.
>
> > > Glenn, how do you envision using the H400 images in KStars?  Just in
> > > the Details window, or also as inline images in the sky display itself?
> > >  For the latter, I think all we can do is add them to the README.images
> > > document, where credit for all inline messier images is listed.
> >
> > Well, it's interesting ... of course I really started thinking about it
> > once I started emailing people for permissions & they'd ask questions! :D
> > Honestly, I think KStars handles inline images better than any other app
> > I have experience ... on Windows for example I use Guide 8 which is a
> > wonderful program, but the inline images show up as square overlaid
> > photos where in KStars they look pretty integrated. Inline images in
> > KStars LOOK like they take a lot of work to get right -- is that the
> > case?
>
> It's not a HUGE amount of work, but it does require manual GIMPing of each
> image.  I basically rotated the image so the major axis is horizontal,
> scaled it down to a small size, and made the background transparent so you
> don't get that "square block" effect in the map.  This actually takes the
> most time, you have to use the "select by color" tool to grab sky pixels,
> and then massage the selection to get rid of cruft.

Wait...
For monochrome images, you could use the image as an alpha channel (inverted, 
maybe -- I never remember if the alpha value 255 means transparent or opaque)
the RGB channels could just be set to white. I think this would give a 
smoother transitione between the bluish background and the image. Maybe this 
didn't work in Qt3 times, but it should work well with Qt4.

I imagine it could work for color images as well -- you just have to use a B/W 
copy of the image as the alpha channel.

Luciano
-- 
Luciano Montanaro //
                \X/ mikelima at cirulla.net