[Marble-devel] Marble and Google Earth

Sun Oct 26 11:34:15 CET 2008

Hi Maurizio,

On Saturday 25 October 2008 11:38:30 you wrote:
> The inclusion of the landsat imagery would be a big step forward, I
> couldn't understand from your mail if you are already working on it or if
> is ToDo later on.

We are not working on it yet. I have some special specs for it set up during 
the next 2 weeks. You'll then be able to participate. That being said I 
consider the LandSat imagery a very important task for Marble 0.7 / KDE 4.2.
Of course an application like Marble needs to have some somewhat acceptable 
satellite imagery so this is really a task that is important to me.

> I couldn't find it in the ToDo list for 4.2 so I think
> you are planing it for later.

There is a release schedule here:

http://techbase.kde.org/Schedules/KDE4/4.2_Release_Schedule

And a feature list here:

http://techbase.kde.org/Schedules/KDE4/4.2_Feature_Plan

There is also a TODO file available in SVN however the aim of that TODO file is 
rather intended for micro-coordination of feature implementation.

As you might realize "Creating a landsat map" is not part of the official 
feature plan. The reason is this: The feature plan mostly covers features that 
are subject to a feature freeze.

I consider the LandSat task to be an extension of Marble's current "Satellite 
View" and as it doesn't require code changes and doesn't change the 
applications appearance we are able to add map data to this map without time 
constraints. 

However if you wanted to add a completely new map then you need to do this 
until string freeze as the name of the map and its legend need to get 
translated. String freeze will happen on November 18th (That's in 3 weeks 
already).

> I live in a little town near Monfalcone (near Trieste) in Italy and I would
> love to help contribute.

Great to hear!

For now I'd suggest 

- That you either have a look at OpenAerialMap.org (as Andrew had suggested). 
While I know about this site I haven't had the time to look into it very much. 
For now we'd be mostly interested in all the free aerial photo data of major 
cities in Europe and North America. I think that this would be a sane focus as 
most of our user base and developer base is located there.

- As an alternative you could also look into historical maps like these:

http://commons.wikimedia.org/wiki/Image:World_Map_1689.JPG
http://commons.wikimedia.org/wiki/Image:Leonhard_Euler_World_Map_AD1760.jpg
http://commons.wikimedia.org/wiki/Image:Moll_-
_A_new_map_of_the_whole_world_with_the_trade_winds.png
http://commons.wikimedia.org/wiki/Image:Nova_Orbis_Tabula_in_Lucem_Edita.jpg

 I'd really like to have historical world maps in Marble.

Maps for Marble need to get provided in plate carrée projection (also referred 
to as "Equirectangular projection"):

http://en.wikipedia.org/wiki/Plate_carrée_projection

There are morphing tools and HOWTOS on the web that can tell you how to morph 
ancient maps into the desired projection. It doesn't require too many skills. 
It's just a matter of doing research on the matter, finding out about the 
copyright and legal terms and sitting a few hours in front of the computer to 
tweak the map according to your needs (As a reward we can only offer fun and a 
prominent mentioning in the "About Marble Dialog" though ... ).

Have a look here:

http://spin3d.com/

The tool "Morph Man" they are using runs on wine btw.. Unfortunately there 
doesn't seem to be any similar easy to use free software tool out there. I've 
checked out lots of free ones already but unfortunately there's none that 
would be up to this task.

The "equirectangular image" that is the result after half of the tutorial is 
what you need.

Once you got an appropriate image it's very easy and a matter of less than five 
minutes to get such a map imported into Marble (and doesn't require a single 
line of code):

Just have a look here for more information on how Marble deals with maps:

http://www.kdedevelopers.org/node/3269
http://www.kdedevelopers.org/node/3272
http://www.kdedevelopers.org/node/3275

> I'm sorry if I'm bugging you with that many questions about your work with
> this project. Maybe if I'd stop you could keep working on it :-)

Well, no problem. I just enjoy to tell people how they can get involved with 
Marble as long as there's the little slight tiny chance that they will start 
to contribute as well ;-)

I'll write a special mail regarding the LandSat data in a few days.

I'll also give some tips and instructions for people who would like to add 
special Venus and Mars maps for Marble (I'd like to have the base data for 
these "themes" as a GHNS download).

Have Fun,

Torsten

>           Maurizio
>
> ---------------------------------------------------------------------------
>-------------- Chiave Pubblica GPG (PGP) reperibile presso
> http://wwwkeys.eu.pgp.net    Identificativo = 0x38BB80EE
> ----------------------------------------------
>
> On Sat, Oct 25, 2008 at 11:08 AM, Torsten Rahn <rahn at kde.org> wrote:
> > Hi Maurizio,
> >
> > Great to see that you've found your way here (make sure that you
> > subscribe to
> > this mailing list or at least have a look at the archive if you want to
> > follow
> > the discussions here).
> >
> > On Saturday 25 October 2008 10:16:50 Maurizio Pozzobon wrote:
> > > Hi, I'm Maurizio, from google groups
> > > I just wanted to point out that I'm not pessimist about open and maps,
> >
> > just
> >
> > > about open and satellite photos.
> >
> > Yes, satellite imagery is indeed a less easy to solve problem than street
> > maps. So let's have a look at street maps and satellite imagery
> > separately:
> >
> > Looking at the progress that OSM has been making in the last few years
> > I'm pretty sure that in about 2 years it will be better than google maps
> > for most
> > of the part.
> > Even now there are lots of cities that are already better mapped than
> > google
> > maps already: On one hand several bigger cities in europe are already
> > mapped
> > with much more love to detail (especially with the important focus on
> > spare-
> > time activities). On the other hand there are lots of cities which seem
> > to suffer from the lack of commercial interest for google maps:
> > Take e.g. Timisoara (Temesvar in Romania): Although it's a beautiful city
> > with
> > about 300 000 people in Google Maps it's nothing but a bus stop! In
> > OpenStreetMap it looks like it's extensively mapped in detail!
> > Looking at the high momentum that OpenStreetMap has got these days (also
> > compared to Wikipedia's early development) I'm pretty sure that this
> > issue will be solved very soon.
> >
> > For the satellite imagery you're right: it's a lot harder (but from what
> > I see
> > that imagery is also subject to higher restrictions in terms of Google's
> > permissions concerning their data).
> >
> > I think there are several things we need to approach:
> >
> > - Make complete usage of freely available data for Marble:
> >  Currently we are just using Blue Marble for the satellite imagery.
> >  The resolution of that data is just a cumbersome 500m per pixel.
> > And yes, that is a completely unacceptable low resolution.
> >
> >  If we'd make use of the LandSat data (the one that NASA polished up for
> > WorldWind) that would bring us down to 15m per pixel for all continental
> > areas: That is about the same resolution that Google Earth has got on
> > "unoptimized areas: I'm currently in Tampere, Finnland which in terms of
> > population is a 208 000 inhabitants city.
> > If you look at Google's Satellite photos you'll see that it has got that
> > 15m/pixel resolution although it's the third largest city in Finland!
> >
> > So that would already be a major mile stone for Marble (We are talking
> > about
> > approximately 120GB of imagery here).
> >
> > In the next step we'd need to deal with the aerial photos: Unfortunately
> > there
> > are very few free aerial photos out there: we'd need to identify where to
> > get
> > the free ones (especially for big cities).
> > Beyond that the whole issue becomes more tedious: people need to approach
> > their government or offices of cities which have access to that kind of
> > "governmental data" and need to ask whether aerial data with a proper
> > license
> > is available (and/or to persuade them that they should make such data
> > available).
> >
> > > I really would like to know if you (as a group) are working on trying
> > > to get better imagery, like contacting the copyright holders and asking
> > > them to donate them or something like that.
> >
> > That would be a task that especially non-programmers could help with to
> > improve Marble and the state of freely available maps.
> >
> > > About OSM I'm trying to get a GPS to update the images of my zone since
> >
> > the
> >
> > > imagery of yahoo doesn't have a quality high enaugh to let me add new
> > > roads.
> >
> > Just out of curiosity: where are you located? :-)
> >
> > We got a few active OSM mappers on this list - like e.g. Inge Wallin who
> > has
> > mapped most if not all of Linköping (and probably during the last few
> > months
> > much of Sweden ;-)
> >
> > Maybe Inge (or somebody else on this list) can give you a few suggestions
> > and
> > tipps on that topic :-)
> >
> > I'm myself currently preparing the NASA public domain moon imagery for
> > inclusion with Marble. Thank god most of the planetary data that exists
> > is freely available. So beating all other existing solutions out there on
> > this topic is just a matter of compiling the data together and editing it
> > in a way
> > that it becomes more appealing to the interested public.
> > I'm also currently about to prepare a HOWTO for how to prepare satellite
> > imagery so that it can be displayed in Marble.
> >
> > Regards,
> > Torsten
> >
> > >           Maurizio
> >
> > -------------------------------------------------------------------------
> >--
> >
> > >-------------- Chiave Pubblica GPG (PGP) reperibile presso
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> > > ----------------------------------------------