The fire insurance maps of Charlottetown from the early years of the last century – the maps I mentioned here last week – are some of my favourite maps of the city: they’re not only beautiful, but they’re packed with all sorts of information about buildings here and gone. The Island Imagined project at Robertson Library has made high-resolution scans of a set of these maps first created in 1903 and evolved, through patch-and-paste, through 1917, and you can view them all at IslandImagined.ca.
Jumping off from some experimenting I did with the 1878 panoramic view of Charlottetown a few years ago, I did some experimenting over the weekend with using Zoomify and OpenLayers to create an alternative way of viewing the maps. What I really wanted to get to was a way of being able to bookmark maps at specific locations and zoom-levels, so I could reference locations.
So I started by grabbing each of the 20 fire insurance maps from IslandImagined at a zoom-level of 7, which results in a nice, large image about 7,000 pixels wide, like this:
wget -O fedoraimages/firemap-01.jpg \ "http://188.8.131.52:8080/fedora/get/imagined:208604/ilives:jp2Sdef/getRegion?level=7"
Here’s a Bash script to do this automatically if you want to do it yourself.
This resulted in 20 large images that I then ran through the free-to-download Zoomify tile-creator, which resulted in 20 directories filled with tiled images.
At this point I could simply drop the Zoomify Flash component into any of the directories and have a Flash-based map viewing solution, like this one for the main index map to the fire insurance maps. This is certainly more usable than the IslandImagined viewer, but it relies on Flash and it doesn’t make for bookmarkable maps.
From there it was a simple matter of crafting (crufting?) some PHP code to create an OpenLayers-based viewer for the same tiles, which has the added features of creating an index page linking to all 20 maps and the ability to bookmark any of the maps at any zoom-level and position.
You can take a look at the resulting map viewer or grab the the PHP code here in github; it’s by no-means feature-complete, but I enjoy the map browsing experience, and I really like the ability to bookmark.