[GRASS-dev] FW: FW: OSGeo-SoC 2016 application

Moritz Lennert mlennert at club.worldonline.be
Thu Mar 24 04:52:03 PDT 2016

Dear Bo,

On 24/03/16 06:26, Yang, Bo (yangb2) wrote:
> Dear Moritz,
> Thank you for the reply, and thanks you and Markus could be the
> mentor of the i.segment project! There are only two days left for
> submitting the proposal, take into consideration I think I need to
> switch to the topic of i.segment project now.

Thank you for the flexibility !

> For my cokriging fusion
> topic I think I could do it after this summer in the future work.

Great !

> I've read the source code and Eric's wiki of GSoC 2012 [0]. I think I
> will prepare the proposal following the direction of adding new
> algorithms to segment an image into objects-- more than
> region-growing algorithm. Moritz, you mentioned segmentation
> algorithm: mean-shift, split-window and watershed.

Yes, as the general logistics of the i.segment module is in place, 
adding new segmentation algorithms should not be too hard, so adding 
several should be possible during this GSoC.

> I think some
> unsupervised classification algorithms would also be possible such
> as: dynamic thresholding and markov random field (MRF).

Unsupervised classification could be an interesting addition.

However, I would think KISS. So, concentrate on the segmentation. You 
can add classification in the the project as a possible extension, in 
case you finish early with the segmentation.

In any case, classification should be a separate module. The idea is to 
have each module do one thing. Currently classification is proposed by 
v.class.ml and v.class.mlR (but the latter is a very simple hack I did 
for teaching - I'm currently busy rewriting it), but they are supervised.

For classification segment characterization is also important. Currently 
we have two Python-based modules for that v.class and i.segment.stats. 
One option might be to think about more efficient approaches and more 
variables for that.

> If you think
> it is OK, I will start the preparing the draft of proposal from now
> on, and I think I could have the first version send back to you by
> tomorrow (Thursday).

Perfect. Markus and I are in Europe so don't forget about time zones 
when thinking about when to send us your draft...

> If you have any suggestions and comments please
> let me know.

Markus can give you more details about the actual implementation. I 
think in your proposal you should show that you have a general idea of 
how i.segment works, and you should review different segmentation 
techniques, possibly with relevant literature references. You might also 
want to have a look at Orfeo Toolbox and their implementation of some of 
the segmentation algorithms.

In general, it would be nice to add at least one or two top-down methods 
as this would allow top-down hierarchical segmentation, while the 
current region growing approach only allows bottom-up hierarchical 

Final note just to make sure that this is clear: please be aware that 
there are other GRASS-related proposals and that we do not know how many 
slots we will get for GRASS. There is thus no guarantee that your 
proposal will be chosen.

Best wishes,

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