It seems like finding changes is harder than it looks! Thanks to everyone who entered our spot-the-difference competition at Lavacon, New Orleans. We had quite a range of guesses but only a few of you got the correct answer. There were nine differences between the two pictures, but the most popular answer by far was eight.

In case you didn’t get the chance to enter our competition why not have a go now with the images below. At the end of this post is an animated image showing where each of the changes are, as well as an explanation on how we used XML Compare to generate the image.

How our XML Comparison tool did

The two images are saved as SVG – Scalable Vector Graphics – an XML format for creating diagrams and other images. Objects in the picture are defined using lines, polygons and gradient fills grouped together as a single item. To create the competition, we simply edited the original XML image to delete some of the objects and create new ones.

To highlight the changes, we created a simple configuration file for XML Compare, our flagship XML comparison toolkit. The configuration file pre-processes the SVG before comparison, adding a few attributes to use as identifiers. Then the comparison runs to create our delta file, which marks each of the changes in the original XML with some attributes in our deltaxml namespace. The final part of the configuration is to process that delta file to convert the changes into an SVG animation that flashes the changes. This is a simple task to achieve in XSLT as the delta file is designed to facilitate XSLT processing.

Here are all the changes:

And in case you are still missing one, here are them marked:

Below is the key template in the XSLT used to create the animation.

The importance of catching change

Ok, this is a simple example and is a bit of fun for a conference competition, but it serves to demonstrate just how important it is to use automation to identify differences in our content. Don’t forget that almost 85% of you failed to find all of the differences, even though there were only nine!

The impact of missing a single change in your document content could be huge, especially if the content is under regulation or documenting mission-critical tools or processes.

If you need to be sure that you know exactly how your content changes from one version to the next, we’d be delighted to speak with you and help you work towards a solution. Just get in touch with us.