Charting Change Atlas: adding zoom

by Peter Tyrrell Tuesday, October 12, 2010 11:19 AM

First go see the Charting Change Atlases sporting multiple layers of zoom at Then come back. I'll wait.

I previously explained in Charting Change Atlas: the technical details the basics of how we turned static TIFFs of historical City of Burnaby geography into dynamic tiled maps upon which float pins marking points of interest. At the time I remarked that the maps were a victim of their own success in that everyone who used them expected them to zoom.

Hardly was I surprised, then, when the fire-eyed demigods behind directed us to add zoom to the maps or die in the attempt. Also I get paid for this stuff.

Zoom levels as tile layers

Normally, when using an online map tool like Google Maps or Bing Maps, a zoom action actually takes you to a new layer of map tiles. The zoom levels are like a stack of pancakes: move up or down a layer and you're eating another pancake entirely. The more you zoom in, the more detailed the tile sets generally get, to further the illusion you are floating above the earth and getting "closer" to the ground.

 map_layers pancake-stack

Fig. 1 Tile layers stacked like pancakes.

Zoom levels as resized tiles

We couldn't do that. The images are what they are, and no separate layers could be had within the scope of the project. Instead, the application resizes the tiles on the fly. That is, the tiles aren't replaced with other tiles, they are blown up when zooming in or shrunk when zooming out.


Fig. 2 Tiles expand or shrink in size when zooming. Unlike pancakes.

Everything shifts

When the tiles resize, everything else has to. Also, all the pin markers have to recalculate their positions. Fortunately, it's just math. Okay, a lot of math. But the new sizes and positions are cached so they don't have to be redone when the zoom level is revisited, and the javascript is refactored to the point where all the zoom elements have to do is call:

map.zoom(settings.zoom.current, newZoomIncrement);


Fig. 3 Relationship between viewport, map, and map's drag area.


Here's how the Modern Burnaby (1955 - 2000) map looks as you zoom out from 100% to 50%. One tile is bordered in red to show how it changes in size. Same tile, three different sizes based on zoom percentage.


Fig 4. above - map at 100%, tile image is 300 x 330 pixels (original size).


Fig 5. above - map at 75%, tile image is 225 x 248 pixels (300 * 0.75 = 225).


Fig 6. above - map at 50%, tile image is 150 x 165 pixels (300 * 0.5 = 150).

BC Workplace Training for Innovation Program

by Kathy Bryce Friday, October 08, 2010 3:56 PM

This program might be a great opportunity to apply for funding to cover the cost of a training session with us on your Inmagic software.  Checkout the program details to see if you qualify, and then contact us for more information.

The deadline for applications for funding of training under this BC Workplace Training for Innovation Program is January 31, 2011.  The program is designed to provide eligible employers with funding for employee training in order to:

  • Improve productivity
  • Support the introduction of new technology, machinery/equipment or work processes
  • Enhance international competitiveness
  • Introduce innovative training and workplace strategies to increase the long term competiveness of the organization and its workforce.

Both businesses and not-for-profit employers may be eligible to receive funding.   Eligible employers must be:

  • Small organizations (less than 50 employees)
  • In good standing with the BC Corporate Registry
  • In existence for one year or more

In addition, organizations must certify that they would not undertake the training without financial assistance from the Province. Complete eligibility criteria are contained in the application form and program guidelines. The maximum funding available per employer is $5,000 and the maximum funding available per employee is $1,500.  An application is not a guarantee of funding. Applications will be processed on a first-come/first-served basis, subject to availability of funding.

Once you have arranged the funding, call or email us to set up a training time.

Tags: Training

Health care expertise at your fingertips 24/7 – MUHC site goes public

by Kathy Bryce Monday, October 04, 2010 10:08 AM

The McGill University Health Center (MUHC) online patient education library or MUHC Health Education Collection (HEC) is now publicly available.  This virtual consumer health library offers a wide and growing range of bilingual educational material, developed by healthcare professionals.   See the press release and about the collection for further information.

The Health Education Collection can be found at: – English Site – French Site

Andornot began working with MUHC on this project in 2007, and the site has been available for MUHC staff only for more than a year while the collection was being developed. We are delighted that the site is now public as it contains not only useful information, but also has some very neat features.

The collection includes:

  • Full-text documents created by health care professionals at the McGill University Health Centre.
  • Links to full-text documents created by other reliable organizations on the World Wide Web.
  • Information about resources that are available on-site at the MUHC affiliated hospitals.

Behind the scenes, the application is hosted on Andornot servers and uses Inmagic WebPublisher PRO for both searching and data entry. Reached via two different URLs, the French and English sides of the site are actually one and the same; and bilingual functionality is provided via resource files easily editable by authorized MUHC staff.

The secure admin interface, accessible via a web browser, allows authorized staff to search on every field or combination of fields and to add or edit records.

 MUHC search results   MUHC data entry

On the public site search results are filtered according to record status, and only selected publicly accessible records are displayed. Users accessing the site from an authorized IP address however, may view additional restricted access records.

The site also features a “Did you mean” option so that for certain common medical terMUHC Did You Meanms a link is displayed to guide users to search using the preferred term. This is an additional database that is searched concurrently and which can also be expanded to include common misspellings. Query logging has been enabled on the site to help with the ongoing process of adding terms to this list based on actual search terms input by users.

In order to facilitate improving content, end users are able to comment and rate each resource. These comments are moderated and the admin interface provides options to review all pending comments in order to approve or delete them.

Andornot has consistently exceeded my expectations in terms of product development and customer service. When we first approached Andornot with this project, we had several unique features that required extensive customization of WebPublisher Pro, including our “Did You Mean” feature and our database’s full bilingual functionality. Andornot not only rose to these challenges, but exceeded them by providing us with elegant and versatile solutions. [Matthew Flanagan, Health Education Collection Librarian / Bibliothécaire de l’Infothèque]

Working with MUHC staff on this project has been a pleasure. We extend our heartfelt congratulations to them on the public launch of an excellent resource.  Contact Andornot for more information.

Vulnerability in ASP.NET applications – Microsoft Security Bulletin released

by Kathy Bryce Friday, October 01, 2010 11:02 AM

A little over a week ago, a security vulnerability was found in all versions of ASP.NET (Microsoft’s web application framework) that could potentially allow private information disclosure. The vulnerability stems from a cryptographic weakness, specifically involving improper error handling during encryption padding verification. Attacks based on this weakness could allow a hacker to decrypt sniffed cookies or forge authentication tickets, among other attacks.

Microsoft has released an out-of-cycle emergency fix to address this security vulnerability. We strongly urge you or your IT staff to go to to download and install all applicable patches on your Microsoft Windows-based Web servers that may be affected by this vulnerability. Additionally, the fix will be rolled out via Windows Updates in the upcoming week or so.

This vulnerability could affect any web sites using ASP.NET, i.e. recent versions of Andornot’s Starter Kits and Inmagic WebPublisher PRO or Inmagic Genie.  It does not impact desktop only installs or clients using the default Inmagic web interfaces.

If you have any further questions regarding applications we have designed for you, please do not hesitate to contact us.


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