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GRASS Google Summer of Code 2016

About

• ​The OSGeo GSoC 2016 main page
• ​Official GSoC 2016 page at Google

Ideas

Post your ideas here or to the ​grass-dev mailing list if you want to discuss them more. To edit this wiki, you need to ​login with an ​OSGeo Userid; read also some help for using trac.

If you are a student you can suggest an new idea or pick up an existing one in any case write about it to ​grass-dev mailing list.

You are invited as well to have a close look at (and re-suggest!) ideas from previous years (​2007, ​2008, ​2009, ​2010, ​2011, ​2012, ​2013, 2014, 2015) which have not yet been implemented. You can also look at accepted GRASS GSoC projects from previous years for an idea of scope.

Include "GRASS GIS" in the title of our idea to easily distinguish ideas and projects inside OSGeo.

Some bigger ideas may have their own pages, so you can link them here. The pages can be either independent if the page already exists (e.g. wxGUIDevelopment/SingleWindow), or more preferably subpages of this page if the idea is (re-)developed for this GSoC. In the later case, use the word "idea" in the page name to distinguish the idea page (e.g. GSoC/2015/CoolGRASSProjectIdea) from the possible student project page (e.g. GSoC/2015/CoolGRASSProject).

Mapnik rendering engine for GRASS GIS

• Mapnik is a powerful rendering engine written in C++ with Python bindings.
• The project tend to add Mapnik engine as alternative backend to ​WxGUI Cartographic Composer
• The implementation will have most of the capabilities of actual ​WxGUI Cartographic Composer
• The plugin will be able to create different format of images (PNG, PDF, etc)
• The plugin will be able to export XML Mapnik file
• A similar implementation is ​quantumnik
• Language requirements: Python
• Mentor: Luca Delucchi
• Co-Mentor: Martin Landa

Complete basic cartography suite in GRASS GIS wxGUI Map Display

• With few additions the wxGUI Map Display could cover large number of cartography needs so that users wouldn't be forced to switch to ​WxGUI Cartographic Composer or different software (Inkscape, QGIS) to create fully-featured map usable, e.g. for scientific publications. The development can happen in phases so that the easy-to-implement things, which gives greatest gain, are done first in case it is not possible to implement everything during summer.
• first phase:
  • store legend, scale bar, north arrow and text (and others if added) in workspace (#2369)
  • add units to legend (optionally also title) as parameter
  • possibility to add any image (as in animation tool), use cases: logo/watermark, workaround for overview maps
  • disable rendering when adding multiple layers into layer manager using Add multiple... (disabled rendering when loading workspace already implemented in r63319)
  • determine map window size without the need to change map display size manually when loading workspace (currently there is a bug, when loading workspace, map display has correct size but map window is smaller and one must resize the window to get the right size of map window)
• second phase:
  • support map units in scale bar, not only meters
  • allow user to set the length of scale bar (in map units)
  • manual breaks/ticks for legend (it is possible to set number of breaks/ticks but the values are not rounded), additional feature would be an option for automatic breaks/ticks every ten, hundred, ...
  • legend background (currently the legend has transparent background), additional features include rounded corners, border and opacity settings
  • general shapes
    • can be implemented using d.* commands (e.g. d.graph) or wxPython or both (wxPython might be easier for interactivity, d.* commands for scripting)
    • use cases: workaround missing background of legend or text, manual marking of special points
  • include map-display-like object
    • useful for overview maps (insets) or histograms
    • would be represented as image but the image would be dynamically generated
    • controlled using something like nested map display
    • might be implemented as a standard Map Display whose saved image would be inserted as an image, perhaps image from other Map Display can be used
    • the important feature is the user does not have to create an intermediate file
    • Simple Layer Manager classes can be used to manage layers in the additional/nested map display
• third phase:
  • implement vector legend:
    • Perhaps we can find some workaround (i.e. some easy implementation) and wrap it into a module, e.g. vector legend drawn as vector with attribute table (enables even line with border thanks to different vector layers).
    • May get complicated with (enhancements of) vector thematic mapping
  • enhance d.vect.thematic
  • make d.text, d.graph, d.erase and perhaps other existing d.* modules accessible from wxGUI
  • implement module which can parametrize workspace (similarly as g.gui.animation is doing for 3D View) and render it with different maps
    • if the implementation would be wxPython free (ideal option) then it would have to translate some wxPython/wxGUI specific things to plain d.* commands
    • this can be also implemented as a script generator (rather than workspace renderer)
    • it should work as a simple automatic map ("atlas") generator and should accept also time series as the input
  • general system and (GUI) manager for additional object on map display
    • should support multiple legends and scale bars
    • should include general shapes
    • should work with any d.* commands, e.g. d.histogram
• It would be great to make as much things as possible to work also in 3D Views (wxNVIZ).
• Thorough (manual) testing on different platforms and version of wxPython is needed (by student or mentors).
• See also:
  • map decorations idea from last year
  • vector legend idea from last year
  • #2582 (implement d.vect.thematic2 addon module features in d.vect.thematic core module)
  • ​grass-dev future of thematic mapping in GRASS
  • ​grass-dev future thematic cartography in GRASS
  • slightly related color tables idea from last year
  • #2080 (changing properties of scale bar or legend)
• Language requirements: Python, wxPython, C and OpenGL will be needed for some parts
• Co-mentors: Anna Petrasova, Helena Mitasova, Martin Landa, Vaclav Petras
• Accepted student: Adam Laza
• Accepted project page: wiki:GSoC/2016/BasicCartographySuiteInGRASS

Generalized GUI code for Qt-based GUI

• wxPython/wxWidgets uses native system libraries for rendering, however there is in fact a lot of platform-dependent behavior and high instability of some features
• Qt is used more and more, QGIS uses Qt
• the current GUI code (wxGUI) often lacks proper design and is hard to maintain, addition of new features requires hacks or refactoring
• a new fresh implementation of GUI is need
• this new implementation should use proper GUI code design so that relevant parts of the code can be used with the new Qt GUI but also with the current wxPython GUI
  • this is necessary to avoid duplication of the GUI code and spending the resources on maintaining two code bases (except for the Qt- and wxPython-specific parts)
  • this will also show that the logic is actually from the graphical representation
  • this avoids dropping wxGUI at the point when the new doesn't have all the features of the new one
  • in this was separated parts of the GUI can be implemented in Qt separately
• Mentors: Martin Landa, Anna Petrasova, Vaclav Petras
• Similar project accepted: wiki:GSoC/2016/PyQtGUI (student: Ondrej Pesek)

GRASS GIS 3D viewer NVIZ module independent of the main GUI

• GRASS GIS 6 has a Tcl/Tk interface to NVIZ, a GRASS GIS 3D visualization library, and the interface is a standalone application in GRASS GIS environment. This has its disadvantages and thus wxGUI in GRASS GIS 6 and GRASS GIS 7 contains in fully integrated 3D view which is using NVIZ library as a backend. However, this also has its disadvantages and ideal solution is to have both.
• The existing examples are g.gui.iclass, g.gui.animation and g.gui.vdigit which is closest to proposed g.gui.nviz because it is also integrated into wxGUI Map Display.
• The implementation should use/reuse/refactor the existing code and all current functionality should be preserved (comparisons with the original version should be done throughout the whole development period).
• The command line interface should be similar to m.nviz.image module but should also accept wxGUI workspace file.
• Some refactoring will be needed to uncouple GUI controls (now part of Layer Manager) and the rendering
  • rule of thumb is that the new code should work even without GUI controls, e.g. as API, and the rendering should be possible not only in the wxPython window but also using m.nviz.image module
  • usage in g.gui.animation could be considered too
  • having a Python API might be quite advantageous for scripting (although m.nviz.image solves most of the problems)
• This would bring benefit to QGIS Processing which is using the standalone Tcl/Tk NVIZ with GRASS GIS 6, so this project should be (co-)mentored by mentors from both GRASS GIS and QGIS projects.
• Language requirements: Python, wxPython, (C and OpenGL shouldn't be necessary)
• Other requirements: basic software design patterns and GUI programming experience

Web-based GUI for GRASS GIS

• This idea will consist in building a web application "WebGRASS" which allows to run GRASS modules on modern browsers.
• The user interface for WebGRASS will be built using ​Wt, Web Toolkit.
• WT provides C++ API for developing web widgets.
• Each grass module is described by an XML file generated the module's --interface-description parameter, the xml file is then parsed to generate the Module Form interface.
• Parsing of the xml file and generating tokens is already available in GRASS GIS.
• The main User Interface will be composed by:
  • Auth-module (user log-in)
  • mapset-location wizard
  • map canvas (based on openlayers)
  • menu bar with same layout of grass desktop
  • toolbar with:
    • pan
    • query
    • zoom in - out - to bbox - to layer - to region
    • save to img mapcanvas
    • save display extent to region
• Command line prompt (a GRASS shell based on IPython Notebook)
• Security concerns
  • By default Web-GRASS is designed to allow access to trusted users.
  • Each user will be an UNIX user on the server with his own home.
  • The web-grass UI interface will be accessible through an opportune registration/auth/login framework.
  • The communication over the network will be encrypted using HTTPS.
  • The input parameters will be parsed and sanitized, this will be part of the UI itself, based on the ​GRASS command-line parsing
  • Will be choice of deployment team to decide to adopt any 'Extra security layer'. This can be achieved using tools like:
    • ​docker
    • ​lxc
    • ​supervisors
    • ​ulimit
• Discussion on the grass-dev mailing-list ​GRASS GIS Web UI
• Detailed ​Idea description
• page for more broad idea description including alternatives (unfinished)
• Language requirements: C++, HTML5, Javascript
• Mentor: Rashad Kanavath
• Co-Mentor: ?
• Sample PyWt implementation to call GRASS commands from a PyWt web UI by ​Massimo Di Stefano
  • ​source code

GRASS GIS Locations created from public data

The organisation of data in Location and Mapsets in the GRASS GIS database is often one of the biggest problems for GRASS novices (see also discussion here: ​http://lists.osgeo.org/pipermail/grass-dev/2015-January/073268.html). The reasons can be that GIS novices and users of some other GIS software (which often tries to hide projection complexity), are not used to solving projection issues, or are not used to centralized organization of their data. However it is also one of the big strength of GRASS GIS esp. in a multi-user environment. This project aims at automatized organization of open, real world data in a GRASS GIS database which can be provided for download. This database will serve as an example for clever organization of spatial data in GRASS GIS and therewith illustrate this feature to new users and help understanding it`s concept. At the same time it provides ready to use real world data (which sometimes comes formats targeted at proprietary software) so that starting working with GRASS becomes more efficient.

• There are some datasets freely available such as OSM, US government data or some INSPIRE (see also: ​http://grasswiki.osgeo.org/wiki/Global_datasets).
• The task of the student would be to write scripts which can run on a server and create GRASS Locations which will be made available for download.
• Additional metadata must be generated too such as web pages and XMLs with links to provide access to these datasets.
• This project should also prepare an infrastructure, so that in the future users can contribute their country-specific scripts.
• Finally, the project would involve writing of a GUI interface integrated into wxGUI start/welcome screen which would offer download of the location.
• This can be also combined with the standardized GRASS GIS Sample Dataset. Maps would get standardized names and one would for example select different area to focus on, e.g. script would be able to download data for the whole USA with focus on North Carolina (creating maps according to the standardized sample dataset) but user can change it to focus on California (semantics and extent of maps would be the same).
• Scripts should be usable as standalone scripts when downloaded separately (so user can download some fresh data or can import into an existing GRASS Location or create a new Mapset). Compatibility with the ​OSGeo Live sampler DVD would be a major bonus.
• Original metadata should be preserved, distributed with the data and used to create a description in the download side and in the GUI.
• Requirements on student:
  • Basic knowledge of GRASS scripting, wxPython, HTML/XML, and UNIX is needed. Some (again basic) understanding of downloading and online protocols will be necessary for data acquisition.
  • Deep knowledge of GRASS GIS is not necessary.
  • The student must be prepared to work with many different data sources and perhaps contact people from community to get suggestion where and how to get the data.
  • Language requirements: Bourne shell scripting, Python (Python would the the primary tool used)
• Mentor: ?
• Co-mentor: ?

Additional segmentation algorithms for i.segment

GRASS GIS has the i.segment which provides the possibility to segment an image into objects. This is a basic step in object-based image analysis (OBIA). Currently, the module only provides one segmentation algorithm: region-growing. Many others exist: mean-shift, split-window, watershed, etc. The code of i.segment was structured in a way that allows addition of other algorithms. The core of the GSoC project would thus be to add a series of these algorithms. In addition, the current implementation only uses distance within the multidimensional space of all input bands as the criteria whether to merge segments or not. Adding shape as an additional merge criteria would be helpful. A first implementation exists in the code, but is not functional as such. If time permits, the student should implement this feature. Special care should be taken for the whole project to code as efficiently as possible, i.e. to make the code run in reasonable time, even for very large images.

The project implies coding in C, with extensive use of the GRASS GIS raster libraries, but with most of the framework already in place.

• Co-mentors: Moritz Lennert, Markus Metz

v.in.osm enhancement

OpenStreetMap is a powerfull dataset. A module to import these data is neeeded. Until now a script, called v.in.osm, exists, but it is able to import data only from a PostgreSQL database after using ​osm2pgsql to convert OSM format to PostgreSQL/PostGIS. This project has to implement the capabilities to import directly the .osm or .pbf format. It should use different backend to import the data, the different options could be:

• ​osm2pgsql using PostgreSQL/PostGIS
• ogr library through ​OSM format
• ​impoosm version 2 is written in Python, version 3 is written in ​go language
• could be possible to develop a C library to convert OSM data directly inside GRASS

• Language requirements: Python, C
• Co-mentors: Luca Delucchi, Pietro Zambelli

Tips for students

• If you have your own ideas we encourage you to propose them. Explain them on the ​grass-dev mailing list.
• If you like some idea here or from previous yeas, write about it on ​grass-dev mailing list and any ideas of your own which could improve it.
• Follow some good practices in your ideas and proposals:
  • Stress why the project would be useful.
  • Show that you know how you will proceed. That is, make sure that you can demonstrate that the proposal is feasible in the given time frame.
  • Be specific in the implementation (or at least as specific as you can).
  • Explain what the final product will look like and how it will work. Perhaps you can add some drawings or mock-ups. (here in a wiki page)
  • Explain how the idea relates to existing GRASS GIS functions, features, and needs.
  • Do not include steps such as "install GRASS", "compile GRASS libraries (on my machine)", "read about the API". You should do this before applying to GSoC.
• Compile GRASS GIS 7 (trunk) from source and prepare environment for development:
  • See links appropriate for you at ​http://grass.osgeo.org/development/how-to-start/.
  • If you get stuck with the setup, feel free to consult the ​grass-user mailing list.
  • Familiarize yourself with wiki:Submitting rules.
• Prove your worth by being active on the GRASS mailing lists (​grass-user, ​grass-dev), fix some ​bugs, and/or implement some (smaller) features, or write some (simpler) GRASS module, and post it to mailing list. There's no better way to demonstrate your willingness and abilities.

• GRASS GIS hopes to participate in GSoC as part of the ​OSGeo Foundation's GSoC program umbrella. See the official OSGeo template for application details and other important information at the ​OSGeo GSoc Ideas page.