Month: April 2015

Viewport meta tag for better page rank in mobile Google search

Algorithm changes are rolled out to Google’s data centres to let mobile-friendly web pages get higher ranking on Google Search. Some sensationalist news outlets call this “mobilegeddon“. I think it is much ado about very little.

Google provides a mobile-friendly test and at first odoepner.github.io did not pass.

So I learned about the viewport meta tag and after adding the following to the head section of my html pages they now pass the test:

<meta name="viewport" 
      content="width=device-width, initial-scale=1.0, user-scalable=yes"/>

About the viewport meta tag

180x130_viewport-meta-tag

The “viewport” meta tag is not part of the official HTML standard, but the validator at the W3C will still accept your pages as valid.

The tag was initially introduced by Apple Safari, but is now widely supported by most mobile web browser. As of spring 2015 Microsoft IE for Windows Mobile is the main exception: It requires some vendor-specific CSS.

Non-mobile web browsers typically just ignore the tag, which is fine because the whole “viewport” concept only makes sense for the relatively small screens of mobile devices.

Lacking a standard definition, for now the best specs are the respective web developer pages at Apple, Mozilla and Google.

Responsive accessible web design

Please note: Passing the Google test is nice for your page ratings, but truly “responsive” web design that works well on all browsing devices requires more effort, as this article on html5rocks.com explains quite well.

And of course, all supporters of an open, inclusive web should always ensure the accessibility of their site, for everyone regardless of disability.

OSGeo Open Letter for Open Formats of LiDAR data

A widely unnoticed revolution is going on in the field of capturing landscapes for mapping and other geographic purposes, and it is laser based:

LiDAR is the technology that uses lasers on small airplanes to literally scan in whole geographic regions and turns them into 3d point clouds. In many ways, especially for high-resolution 3D elevation data, LiDAR is already replacing traditional satellite based approaches, and enables a plethora of applications in many fields of science and business.

So far, the de-facto standard file formats for storing these “point clouds” are LAS and its compressed variant LASzip (Open Source, LGPL, developed by the German software engineering firm rapidlasso).

But recently ESRI, the market leader for Geographic Information System (GIS) software, has stepped into the arena with a closed source compression format, deceptively called “Optimized LAS” (aka *.zlas), and is positioning it as a direct competitor to the widely used Open Source LASzip format.

The closed-ness of the ESRI file format and the resulting fragmentation of the LiDAR community and its data stores, has now lead to a concerted “Open Letter of the Need for Open Standards in LiDAR“, signed by many representatives from LiDAR related companies, research institutions and the wider geo-informatics community.

I hope that this is a step towards protecting the LAS format from “hostile takeover” by ESRI and I have added my name to the signature list today.

In the very least the Open Letter will raise awareness of the importance of Open Standards and Open Source in the essential field of geographic data, data about our planet, about the world we all live in, which should be Open Data, available to all via Open Standards via Open Source tools, not locked away in vendor-proprietary binary formats that can only be read and processed using that single vendor’s tools.

How to use Oracle Java 8 plugin in Iceweasel on Debian wheezy

Download the JRE from Oracle website.

Then perform the following steps (adjust the tar.gz filename according to what you downloaded, and replace “jre1.8.0_40” with the directory of your extracted tar.gz):

cd /opt
sudo tar xvzf ~/Downloads/jre-8u40-linux-x64.tar.gz
sudo chown -R root.root jre1.8.0_40
sudo ln -s jre1.8.0_40 jre
sudo update-alternatives --install /usr/lib/mozilla/plugins/libjavaplugin.so mozilla-javaplugin.so /opt/jre/lib/amd64/libnpjp2.so 1000
sudo update-alternatives --set mozilla-javaplugin.so /opt/jre/lib/amd64/libnpjp2.so