On Thu, May 24, 2012 at 7:29 PM, Eric Momsen <[email protected]> wrote: > Hi, > > Thanks everyone for the nice greetings, I'm very impressed with how polite > and helpful the GRASS community is. > > There is a wiki [1] and source code repository [2] for the Image > Segmentation - Google Summer of Code project. > > The mentors for the project have already provided a lot of advice, if there > is anyone else with an interest in segmentation you are welcome to add to > the Specifications or other areas of the wiki. > > For the "code" I have started an outline, but I think there are still too > many questions to call it pseudocode yet!. Many of the questions are for > myself to research and answer. Of course, I welcome input and suggestions > for all of it, but some of the bigger questions are: > > 1. How to best deal with images that are larger then available memory. (I > assume too much disk I/O would be slow, but simple tiling could lead to poor > segmentation at the tile borders.)
There are two tile cache mechanisms in GRASS, once the read-only cache used by r.proj and i.rectify, once the more flexible and read/write cache of the segment library. In this case I would opt for the segment library because the data stored there can be any size, determined on run-time. You could e.g. put all input bands (all maps in a group) into one array and cache that array with the segment lib. The size of the array corresponds thus to the number of input bands. > > 2. How to find neighbors. (Is this already available somewhere in GRASS?) What neighbors do you mean? The eight adjacent neighbors or neighbours in a larger neighborhood? You could look at r.neighbors for a general solution of any neighborhood size and at r.watershed for the eight adjacent neighbors. > > 3. Would any functions would be useful as a general library function. What functions exactly do you have in mind? > > 4. If library functions are already available for any steps. > I hope the above comments help a bit. A lot of useful functionality is implemented not only in libraries but also in modules. > > I saw GSoC is on the agenda for the Sprint, if it would be helpful (and > isn't too early in the day!) I can join by Google video / IRC / etc. > We address items on the agenda more in an ad-hoc approach, no fixed schedule, but you can contact us any time. Hope that helps, Markus M > Regards, > Eric > > [1] http://grass.osgeo.org/wiki/GRASS_GSoC_2012_Image_Segmentation > > [2] > https://trac.osgeo.org/grass/browser/grass-addons/grass7/imagery/i.segment > > _______________________________________________ > grass-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-dev _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
