Category talk:Atlantic hurricane season maps

Creation

These images were all downloaded/created from [1] via a script using bash, wget, and ImageMagick on Debian/Linux.

year=1851
while test "x$year" != "x2005"; do
  wget http://www.aoml.noaa.gov/hrd/hurdat/track_maps/$year.jpg
  convert $year.jpg "$year"_Atlantic_hurricane_season_map.png
  rm $year.jpg
  year=$(($year + 1))
done

The same source will no doubt include future track maps as well. It also includes higher-resolution maps in PS format which could someday be used to replace these.

Usage

My plan is to include these automatically inside the hurricane articles. For instance [[:Image:{{PAGENAME}}_map.png]] will let the file be included automatically, either in {{Infobox hurricane season}} or {{Hurricane season map}}. This will run into a problem when used for the "collective" seasons (1889 and earlier). Here they'll have to be included by hand. Jdorje 01:05, 23 October 2005 (UTC)

File sizes

I noticed that the file sizes for these images are around the 500K mark and even the thumbnail images used in articles take a noticably long time to download. The images are stored as full RGB PNGs, which since there are large areas of solid colour (white mainly) is rather wasteful. You can halve the file size, without reducing quality, by indexing the PNG.

For example, Image:1937_Atlantic_hurricane_season_map.png is 507.3K at the moment. I indexed it and it went down to 241.6K!

This would take only a few extra command-line options on the convert command above. To be precise, you'd just need to add:

+dither -colors 256

--David Johnson [T|C] 16:31, 4 January 2006 (UTC)