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From "Martin Desruisseaux (JIRA)" <>
Subject [jira] [Created] (SIS-307) Create the foundation of a module for remote sensing data
Date Thu, 18 Feb 2016 10:01:18 GMT
Martin Desruisseaux created SIS-307:

             Summary: Create the foundation of a module for remote sensing data
                 Key: SIS-307
             Project: Spatial Information Systems
          Issue Type: New Feature
          Components: Storage
            Reporter: Martin Desruisseaux
            Assignee: Martin Desruisseaux

This is a proposal for a [Google Summer of Code|] (GSoC)
project. The Apache SIS library needs a module for efficient handling of large _n_-dimensional
remote sensing data. The module shall:

* Provide a common approach to the reading and writing of grid coverages applicable to simple
imagery as to multi-dimensional data structures.
* Allow operations that preserve the scientific meaning of data (e.g. distinguish between
measurements and missing values, why the value is missing, estimation of accuracy).
* Be compliant with international standards, in particular (but not only) _Schema for coverage
geometry and functions_ (ISO 19123) and _Web Coverage Services_ (WCS). The module should provide
extensions to those standards only for aspects that are not covered by an existing standard.

This module will be a redesign of coverage module that existed in previous projects. In particular,
the coverage module of the [Geotk|] project will be used as a starting
point. However an important focus of this project is to fix known limitations of previous
projects, for example:

* Too strong reliance on {{javax.imageio}} API, which was designed for two-dimensional images.
That API is difficult to generalize to three- or four-dimensional data accesses.
* Too strong reliance on {{javax.imageio.metadata}} API, which is basically a XML document.
Ordinary Java objects are more convenient to use and the ISO 19115 international standard
can be a good model for those objects.
* Too strong restriction on the grid geometry (in previous projects, the conversion from pixel
coordinates to "real world" coordinates is restricted to an affine transform).
* Only quadrilateral grid coverages were supported.

h3. Proof of concept
In order to ensure that the module is on the right track, a small application (either a desktop
application for browsing images or a simple web application conforms to the WCS standard)
will be created. This simple application will be created in collaboration with volunteers
of a space agency, and should be able to:

* Read at least one image format of that space agency.
* Allow diffusion of those data in time range, sub-area, sub-sampling and layers selected
by the user.
* Allow searches in some metadata fields (to be selected according the needs of the space

h3. Non-goals
This GSoC project is not expected to create a fully functional coverage module in 3 months.
Performance is not a concern for this initial stage (in particular, building index or storing
information in a database is out of scope), except that the application shall not load all
data in memory: the application should prove that it can work with only a small fraction of
the data in memory and load the remaining parts when needed.

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