[Qgis-user] Re: New python plugin: "1-band raster colour table"

[Benoit de Cabissole]

Hi Giovanni,

Thanks for testing this plugin.

See comments below.

On Friday, 23 July 2010 18:46, Giovanni Manghi wrote:
> 
> Hi!
> 
> 
> On Fri, 2010-07-23 at 10:01 +0200, Benoit de Cabissole wrote:
> > Good day Agus,
> > 
> > Thanks for your words of encouragement!
> 
> 
> sorry, I missed to leave my feedback in the past days.
> 
> I also think that this is a great addition to QGIS! thanks! potentially
> it can fill the void about the lack of symbology colormaps for rasters.
> I would love to see this as a core feature instead of a plugin.
> 
> http://trac.osgeo.org/qgis/ticket/782
> 
> I tested the plugin under qgis 1.5 in Ubuntu 10.04 and this are my first
> impressions:
> 
> *) it takes really a lot to load rasters, even small ones (a few MB
> tiffs).

I totally agree with you that the time it takes to read the raster is far too long due to the need to get all values of the raster. The original program is written in VB6 and is far faster than the plugin but limited to Windows.
My knowledge of python and the QGIS API is close to nill, so any help on how to speed up things are more than welcome.
Obviously, programming the plugin in C++ could help a lot, but this is far above my capabilities!


> *) there is no way to stop loading the raster after having clicked the
> plugin icon

I'm busy on the next version that will have progress bars (and an abort button), so that user can at least see that something is happening, albeit at a snail pace :-(


> *) the GUI has a few glitches under linux, gnome at least

For the GUI glitches, again, it must be due to my lack of experience with Qt. I will try to fix that as well.
Something is bothering me in the image you have attached: does the raster get coloured after you click 'Create'? Or does it stay grey?


> *) the new colormap should be directly imported/used

Again this is due to my lack of knowledge of the QGIS API. I simply did not find how to load a colour ramp into a raster, the API is very daunting here!

As a side note, when you create a colour table, the raster data is saved in a compressed form so that if you use the plugin on the same raster again it will open much faster.

Cheers,
Benoit

>  
> 
> cheers
> 
> 
> -- Giovanni --
>