gvsig mobile

This category contains 35 posts

Google’s WebP vs JPEG: a more comprehensive test

My previous post was a bit unfortunate. The only relevant conclusion of it is that WebP does provide better compression ratios than JPEG for the same level of lossiness. Here is a new comparison method: Take the original image and compress it to WebP and JPEG using all possible quality levels. In both cases, the … Continue reading

Just a test on this funny Fedora netbook

The OLPC XO Fedora laptop has fallen into my hands by chance for a few days and I have obviously tested Unofficial gvSIG Mobile for Openmoko on it. The latest swt.jar for Linux x86 devices looks really nice on it. Background is a tiled (client side) Japanese ArcIMS service: The Open Mobile IS synchro engine … Continue reading

On-the-fly reprojection of tiles using your favorite conventional WMS servers

If we accept Spherical Mercator tiles and the ZXY storage scheme as standard and still wish to use all the nice WMS servers we know, we can easily set up a middle tile server like this: For example, this request gets a OSM-like tile from a conventional Bavarian WMS server:,TK50&x=8711&y=5643&z=14 The advantage of this … Continue reading

Water utility management using Open Mobile IS & gvSIG Mobile

A nice example of how data synchronization and GIS software integrate on a mobile platform: Manuel Gomez (from Ubikis, Lyon, France) has published a proof of concept application for Windows Mobile where he integrates gvSIG Mobile and the Open Mobile IS framework. From the main control panel, you can switch between the map and the … Continue reading

Madrid 1656

The year 1656 saw the creation in Madrid of -at least- two graphic masterpieces: while Velázquez was doing that, the Portuguese cartographer Pedro Teixeira was doing this (click to enlarge): A superb map of Madrid in the times of the late Spanish Habsburgs. You can download it as a georeferenced (EPSG:25830) ECW file and also … Continue reading

Large shapefiles on small screens using a drawable spatial index

Sometimes a large vector layer needs to be rendered on a relatively small area on the screen. This happens especially with mobile devices, where screen size ranges between 240 x 320 and 480 x 850 pixels. If the vector layer affects a small number of pixels, it makes no sense to go through all the … Continue reading

Tile pyramids versus TIFF, ECW and such on mobile devices

Due to poor performance and portability issues associated with raster libraries, I don’t think it’s a good idea to use raster formats such as TIFF, ECW or MrSID on mobile devices such as (smart)phones, pocket PCs, tablets, etc. Google Maps, OpenLayers and OpenStreetMap have made quadtree tiles very popular. Initially intended to increase web mapping … Continue reading

Doing nasty things with Spherical Mercator tiles: Ordnance Survey 1857 map versus OpenStreetMap

Since tiles from different sources are being stored in the application cache with a common namespace, you can move tiles from one folder to another to get funny, revealing combinations: And here is a nice screenshot in full-screen mode (click to expand):

Recommended settings to run Java applications on the Neo Freerunner phone: SHR & Jalimo

1. The operating system As far as I know, the word Openmoko means three different things: It’s the name of a project dedicated to delivering mobile phones with an open source software stack. I’ll refer to this as Openmoko(p). It’s the name of the Linux-based operating system that is part of the mentioned project. It’s … Continue reading


The situation in Haiti is an example where synchronization of POIs is a good option: As soon as a surveyor reaches an internet-enabled spot, new POIs are added to the database and WMS clients (for example in a coordination office) can see the changes instantly. As new POIs from surveyors A, B, and C get … Continue reading