Geocortex Blog

Our products team has been working for months with today’s date looming on our calendars. Earlier this year, we committed to delivering a Geocortex Viewer for Silverlight 1.0 by the end of the 2010. And we took that commitment very literally.

I’m happy to announce that our collective fear of December 31st coming too soon has been by replaced by excitement and celebration: today we released version 1.0 of our Geocortex Viewer for Silverlight. It has been a huge project, and I think it’ll be well received by users of Esri’s ArcGIS Server.

Oh yeah, the Geocortex Essentials 3.3 beta ships today too. Thanks to the team that has worked so hard to ensure all this comes together, as well as to everyone who has provided input during the development iterations.

Lot’s more information to come including feature tours and UX design discussion. Until then, happy new year… we’re taking tonight off.

There’s a lot of cool features in the 3.2 release of Geocortex Essentials we just announced, but I’d like to focus on one in particular.  We’ve made some architectural changes to our printing so that we can now support the generation of really, really big printed maps.

Geocortex Essentials has included printing from JavaScript, Flex, and Silverlight since its first release for REST technology.  The print template designer allows authors to add multiple map services, a legend, an overview map, a north arrow, corporate logos or images, titles, copyright messages, client graphics, scale and projection information and all the other stuff you would want on a printed map.  Now, authors have the freedom to make their templates as big as they like, and allow users to run print jobs with them at high resolutions!

There’s a few printing solutions on the market, but I don’t know of any others that can create a 36×44 inch print at 600 DPI from a Flex or a Silverlight-based application.  The image resulting from the above specs is around 570 million pixels.  At 32 bits (4 bytes) per pixel, we’re looking at about 2.3 gigs of images (more if you count the tiles requested from every map service before they’re blended together into a single image).

Here’s an example of a 42×36 inch PDF generated at the 300 dpi.  It shows the effect of the bark beetle within the douglas fir habitat on the North Fraser river in BC.

WARNING:  It’s a ~40MB download (which is still big, but a lot smaller than several gigs thanks to JPG compression).  The preview image below links to the file – considering the file size you may want to “right-click, save as” instead of loading the PDF into your browser.  Also, make sure to “zoom in” once you’ve opened it up!

This morning I attended an Esri caching webinar where they discussed the new enhancements in ArcGIS Server 10.  With 10, it is easier to copy your cache between machines, it takes less time to build a cache, you can mix file types, and merge tiles from different sources into a collaborative cache.

Compact vs Exploded Caches

AGS 10 offers a new “compact” cache storage format, as well as the original “exploded” format.  The exploded format creates caches as you saw with previous versions, where your cache is comprised of 1000s of image tiles organized in folders.  The new compact format groups a large number of files into a .bundle file.  Each cache scale now consists of at least one .bundle & .bundlx file (the tiles are indexed by the bundlx file).  Each bundle covers a specific map extent and can hold ~16000 tiles.  This means that the number of files in your cache is hugely reduced, and you have a much smaller number of files to copy.  An example in the webinar referred to an exploded cache of 3.8 million files which took 9 hours to copy, compared with the same map service using a compact cache which took only 8 minutes to copy. 

Exploded caches can be converted to compact caches, and vice versa, using the Export Map Server Cache tool.  You can also convert your 9.3.1 caches to compact caches.  Esri recommends you use AGS 10 SP1 for cache conversion.  The compact cache will build “several times faster” than an exploded cache.  There should be a negligible difference in performance between a compact and exploded cache as well.

Mixed Caches

Mixed caches are another new feature available with AGS 10.  This enables you to have both PNG and JPG tiles in the same cache.  Ordinarily when overlaying caches you would see a white boundary with a purely JPG service.  In a mixed cache, only the images that require transparency (touch the boundary) are PNG.  The interior tiles that don’t have to be transparent are JPG.  This means you use less disk space and still get the benefit of transparency when overlapping map services.  For imagery caches, keep JPG quality above 60, and for non-imagery use a higher quality JPG (90+) in order to see near seamless quality between the PNG and JPG tiles.

Collaborative Caching

Collaborative caching starts with a regional base map that covers the whole extent of your area.  You can then import data from different sources into your cache, providing they use the same tiling scheme.  You can merge data by scale, extent or feature class boundary.  If you had higher resolution imagery available within a city boundary, you could import it using the city boundary feature class – it even imports down to the pixel so you get an exact boundary.  In this example, you no longer have to overlay two separate services.  Likewise you can export by scale, extent or feature class boundary if you just want to use part of a cache.

A recording of the webinar will be available in a few weeks on the Esri training website, or you can catch the live version again today at 3pm PST.