Warping maps: map reprojection on HTML5 Canvas

Proof of concept for the transformation of map projections with calculation in JavaScript and displaying with HTML5 Canvas in a modern web browser.


Developed during the FOSS4G 2009 code sprint in Sydney in September 

More details:

Foto from the OpenLayers code sprint blog post: Klokan Petr Přidal showing Mike Adair and Marc Jansen that proj4js can do more than just vector reprojection.


Raster map reprojection (warping) with JavaScript and HTML5 Canvas

I wanted to create something nice during the FOSS4G Code Sprint, and I ended up programing a prototype of the client-side raster reprojection implemented with the HTML5 Canvas, JavaScript and Proj4js. It is kind of port of gdalwarp into the web-browser environment.

To try it you need a web browser which supports HTML5, it means the latest version of one of the Firefox, Chrome, Safari or Opera.

Have a look at the demo:

Link: http://www.klokantech.com/labs/map-reprojection-html5-canvas/

It is just a prove of concept in this moment, but I am sure you will come up with plenty of ideas for practical application... post a comment! ;-)


Garmin Custom Maps KMZ from GeoTIFF via MapTiler / GDAL2Tiles

UPDATE: MapTiler 0.6 supports Garmin!

Download the latest version from http://www.maptiler.com/

See the video tutorial:
Step by step documentation: http://www.maptiler.com/how-to/garmin/

Previous post:
Garmin rolled out beta version of firmware for their latest generation handheld GPS receivers allowing you to display scanned paper maps and another raster data in their navigation devices. They have chosen to do that with a simplified variant of Google Earth's KMZ format, so you can prepare maps for your Garmin even in Google Earth.

On the Internet you can find plenty of free maps in the standardized GIS formats, which can be now transfered into your GPS device. Look at USGS topographic maps, USFS maps, or NOAA Nautical Charts, etc.
These geodata has already high quality georeference embedded, but they are using different coordinate systems and map projections then Google Earth and this complicates the conversion into the form supported by latest Garmin handhelds.

I am the author of MapTiler - a graphical application for Windows, Linux and Mac OS X, which allows extremely easy and user-friendly transformation of raster geodata into the web presentation (mashups) and tile overlay for Google Maps, Bing, Yahoo Maps, OpenStreetMap or Google Earth. You can download and use this software for free.

The application now supports direct export into the Garmin Custom Maps KMZ. If you have one of the supported Garmin devices you can try an example map: the USGS map of Grand Canyon encoded for Garmin GPS KMZ (9 MB) or the alternative from USDA Forest Service. (10 MB)