A professional friend of mine recently made me aware of a new online mapping tool named OpenStreetMap, and I thought it would be worth a blog entry to try and help draw a little more attention to the effort. Founded by Steve Coast, OpenStreetMap is a free and editable mapping tool that hopes to eventually compile data of the entire planet. It allows you to view, edit and use geographical data in a collaborative way from anywhere on Earth. Great idea! I wish them all the best in the months and years to come as they attempt to expand and improve their image data.
Of course, one of the items of primary interest to me in evaluating their service was to see how efficiently they were optimizing their image tiles which make up the interface. Many other services such as Google Maps, Yahoo Maps, MapQuest, etc. leave a great deal of room for improvement related to image optimization, and I wanted to see how OpenStreetMap might compare.
Unoptimized 256×256 pixel 254-color (8-bit) .png image – 15,843 bytes
Optimized 256×256 pixel 64-color (6-bit) .png image – 10,455 bytes
OpenStreetMap seems to be in about the same boat as many of the other mapping services out there…with a 34 percent larger image file size than is actually necessary. Obviously, file size savings would vary from tile to tile (across millions of image tiles). However, the greater point is that a tremendous opportunity exists for OpenStreetMap to dramatically decrease image load times and bandwidth consumption within their service.
I also took a look at their logo on their web site as well:
Unoptimized 120×120 pixel 24-bit .png logo – 24,142 bytes
Optimized 120×120 pixel 24-bit .png logo – 20,641 bytes
The optimized version of their logo could be reduced in size by roughly 15 percent, although if they could re-configure their page to avoid the need for image transparency and use an 8-bit .png image instead, the size of that image could be reduced to just under 7 KB in size…a dramatic improvement.
I’ll see what I can to about contacting OpenStreetMap to gage their interest in optimizing their .png image tiles. Who knows? Being 25-30+ percent faster in download/display times than many of the other online mapping services out there might be key in their effort to thrive in years to come!
