I got a great Christmas present this year: two books by Nathan Yau from Flowing Data. They include some great suggestions for thinking about the design of figures, inventive ways to analyse data and some nice new sources of data as well. One delightful idea was a neat way to view the overall story from a large number of photos in a single graph. Nathan uses the example of his wedding photos. By extracting the most common colour from each photo and then arranging them by the time they were taken you get a lovely impression of what the focus of the celebration was at each moment.
After Christmas my family and I went to the beach for a week and I took a bunch of pictures. So, I thought I could apply the skills I learnt from Nathan’s book to these pictures. It was a fun process and I think the result is not only beautiful but tells the story of our summer holiday really well.
1) The first step was choosing the most common colour in each photo. The first time I tried this I came up with a week’s worth of white photos. Then I realised that white (or possibly black) would always win because there is very little chance of any other colour being well represented among the 16,777,216 potential colours that are recorded in an RGB image. So, I reduced the number of colours used in each photo using a process called colour quantization. With a bit of trial and error, mapping each photo with 16 colours removed most cases in which white was the most common colour but still gave some nice variation between the photos.
2) Below the graph of photograph colours I’ve included some data showing the weather for each day. I got this from wunderground.com.
As you can see – the photographs are dominated by the colours of the beach: sandy brown, blue sky and green sea. It was definitely a summer beach holiday. There are several parts of the story from the week that are nicely shown:
1) I didn’t take the most photographs on the days with the best weather. In fact, Wednesday had clearly the best weather (highest temperature and lowest humidity) and I left the camera in the beach house. We were having too much fun to take the time to take pictures.
2) A cold front came through on the Thursday (you can see the spike in humidity and the decrease in temperature) but we still played at the beach. Interestingly, the front seems to have changed the colour of the water, from blue/grey to green.
It was a great summer holiday and we had a lot of fun. Thanks to Nathan Yau’s books for suggesting a great way to remember the fun.