Temporal Imagery Comparison Technique

I was recently made aware (thanks Minfeng) of a cool infographic put together by ABC News in Australia showing a slick interface for comparing two pictures of the same location. You can see the pages here and here. In this case they are using the overlay technique to allow users to evaluate the impact of the Brisbane flooding by comparing aerial imagery taken before and immediately after the flood event.

The imagery comparison technique was so compelling to me that I thought I would see if I could do it in Magik. My scenario was to use imagery available via Web Maps Connector to compare imagery supplied by Bing with imagery supplied by NearMap. What I came up with was a class called a canvas_comparer. It could be used to take two snapshots of the same canvas with different contents and then easily compare the two snapshots dynamically as sliding overlays.

This video demonstrates how it works. I'm wondering if there are other temporal-type applications that this might work for. (I threw this canvas_comparer together in about 1 hour using Graham's very cool Dialog Designer. If you haven't tried the tool yet, you should!!).

Viewing Brisbane (AUS) flood imagery in Smallworld Applications

If you have been reading world news recently, you will have seen much reported about flooding in and around Brisbane, Australia. The disaster has been devastating to the people in its path and I wish them well as they try to piece their lives together in the aftermath.

I realized that there might be value in taking recent flood imagery and integrating it as a layer in various Smallworld telecom and utility applications. With this data a technician could determine which hubs or switch gear might be under water. The key to this, though, is to have near realtime flood imagery. Enter NearMap.com. They have flood imagery as of January 13 for Brisbane. You can view all their activity announcements at http://twitter.com/NearMap.

I have created a silent video of a proof-of-concept of integrating Smallworld with NearMap's Brisbane flood imagery. At the end of the video there is also a section on creating Smallworld trails from OpenStreetMap data. Remember that this is all data accessed over the web with no need to host any data on your servers.

The integration is done with Web Maps Connector which is a product offered by my employer iFactor Consulting.