[GRASS5] r.wavelet

[Andrea Antonello]

> Thanks Andrea for prompt replay.
> In r.wavelet code I saw "Gmake" file.
> So I thought that changes are necessary
> to use it with grass6. Can Gmakefilework
> with grass6?

Yes, I simply included the r.wavelet folder in my raster folder and everything 
works.

I have a quite different problem, which I first thought is a code problem of 
wavelets, but I'm not that sure any more.

Some lines of background (very fast, give me the chance :o)): the wavelet 
filtering process creates from one map four maps of half of the resolution. 
So every processing level takes map

1

and creates four maps:

2_11, 2_12, 2_21, 2_22

that have obviously same boundaries but different (half) resolution.
Next level takes the map of the lower resolution map

2_22   (the others contain the difference values in x, y and xy)

and create:

3_11, 3_12, 3_21, 3_22

and so on for all the decomposition levels.


Things should work properly as they did, since the cellhead files look right:

map 1:

proj:   99
zone:   0
north:   730000.0
south:   590000.0
east:   850000.0
west:   580000.0
cols:   2700
rows:   1400
n-s resol:   100.0
e-w resol:   100.0
format:   -1
compressed:   1


map 3_22:

proj:       99
zone:       0
north:      730000
south:      590000
east:       850000
west:       580000
cols:       337
rows:       175
e-w resol:  801.18694362
n-s resol:  800
format:     -1
compressed: 1

So the boundary are the same, but when I visualize, the result is the 
following:

http://www.hydrologis.com/testfiles/wavelet_pbl.png


The bigger map is the third level of wavelet decomposition of the smaller map.
The boundaries are the same, so I can't understand why the lower resolution 
map gets stretched.

In the last years did something change in the raster apis, which I missed?

Sajith, can you try and tell me if you get the same results?

Has anyone some hint? I'm not really happy to go through some code I didn't 
open for years if it is not really necessary. 


> Also why r.wavelet is not part of grass6 distribution?

I guess because they seem not to work at the time :)
Honestly you are the second person that ask for multiresolution analysis in 3 
years, so I think that is why they are in the add-ons section. 

> Does it lacks something, like documentation?

No, the manual pages were made properly and exaustive.


Hope this can be solved,
Cheers,
Andrea








>
> On 7/3/05, Andrea Antonello <moovida at katamail.com> wrote:
> > Hi Sajith,
> >
> > >        I am planing to do some image processing based on wavelet.
> > > I checked the r.wavelet module in the grass addon section, but it is
> > > made for grass 4(?). I wish to upgrade it to the present grass version.
> >
> > the modules were made for the grass5 version. I got in touch only once
> > again with the wavelets modules in grass6, where they gave some strange
> > output, but at that time I had no second free to understand what it was.
> > Since the raster api didn't change (someone correct me if it's not true),
> > those modules should work out of the box.
> >
> > > I am not a grass developer now, and I dont know the changes in grass
> > > libraries between version 4 and 6.
> > > Can some one guide me on how to proceed?
> >
> > What do you mean? Compilation into the release or usage?
> > The man pages in the package should fullfill the second.
> > However for a first quick use:
> > r.biowave.dec input=<mapname> output=<outputname> filter1=sp02.ir
> > filter2=sl05.ir filterpath=<folder where the filters (sp02.ir and
> > sl05.ir) are with / at the end>  NumRec=3
> >
> > This will perform a 3 step wavelets decomposition.
> > The maps will be created and the names are selfexplanatory.
> >
> > If I remeber correct, the starting map has to be floating point, else
> > there will be strange results.
> >
> > Cheers,
> > Andrea
> >
> >
> >
> > --
> > _________________________________________________________________________
> >___ HydroloGIS - Environmental Open Source Solutions
> > www.hydrologis.com
> >
> > Andrea Antonello
> > Environmental Engineer
> > mobile:  +393288497722
> >
> > "Let it be as much a great honour to take as to give learning,
> > if you want to be called wise."
> > Skuggsja' - The King's mirror - 1240 Reykjavik
> > _________________________________________________________________________
> >___

-- 
____________________________________________________________________________
HydroloGIS - Environmental Open Source Solutions
www.hydrologis.com

Andrea Antonello
Environmental Engineer
mobile:  +393288497722

"Let it be as much a great honour to take as to give learning,
if you want to be called wise."
Skuggsja' - The King's mirror - 1240 Reykjavik
____________________________________________________________________________