The sys admin's daily grind: GIF animations
Trees and Clouds
Beyond flashing web emoticons, animated gif images can present trends that catch your eye in system monitoring.
I recently started experimenting with building animated GIFs. Not because I wanted to add more kitty content to the web (our 16-year-old cat [1] is allergic to exercise, so a still – or prone image – would have done that job perfectly), but because I wanted to visualize cloud movements on the web. The idea came to me from a hurricane warning. By pointing a webcam at the treetops and clouds, I could assess from anywhere in the world whether my home was threatened.
Said and Done
Unfortunately, the Internet connection in the lowlands of the lower Rhine region of Germany is about as dynamic as my cat; you can forget all about streaming. I have the camera grab an image every few seconds and then concoct an animated GIF from the results. The bandwidth-saving results look good on the website for my amateur weather station (Figure 1) [2].
A myriad of tools can create animated pictures, but most of them are graphical rather than scriptable. I decided on convert from the ImageMagick toolkit because it does exactly what its name suggests, and more. In the simplest case, I can convert the images from my webcam to GIF like this:
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