Inspired by a comment on my previous blog post about O2 image compression, I want to set the record straight about my personal opinion on compression in the context of mobile broadband.

Compression is used many places, and also in normal broadband connections, so there’s nothing new in that. I’m all for it. If compression can make the transfer speed from web site to my computer faster, then please, go ahead. However, I do have a strong opinion about the compression strategy that is being used. For the sake of example and because many user of this blog site are not techies, let me try to explain what O2 is doing this way:

Lets say you have 1.2 GB of images on your computer that you have to transfer another computer using your 1 GB flash drive. You know, the USB dongles. You have no other means of transporting them. To make this possible you consider compressing the images. There’s two strategies for this:

1. Use zip from to make a compressed archive that is less than 1 GB in size. After doing this, you transfer this archive to your flash drive. You then transfer the archive to the second computer and decompress the archive. You have now succeeded in transferring the files. Badabing!

… or…

2. You choose to open every image and save them again, this time, however, in a lesser quality. After doing so, all the images end up being less than 1 GB all in all. You copy them to the flash drive and from there to the other computer. You have now succeeded in transferring the files. Badaboom!

So what is the major difference in these two strategies? Both did the job, right? Well, basically the first based on lossless compression. It means, that the files, after being decompressed, are in the same state and quality as before compressing them. The second strategy, however, is based on a lossy compression. You’ll never be able to go back to the good quality you had before compressing the pictures. The pictures have been changed “physically” and the low quality will be visible.

In the case of O2 image compression, they’ve chosen something similar to the second strategy. The images travel to your computer like this:

Web site –> (High quality image) –> O2 servers (transforms image) –> (Low quality copy) –> You

I have no problem with compression being used in the dialogue between the mobile broadband provider and my modem as long as it is lossless. But, like O2, using a lossy compression strategy based on “per image” compression with no possibility to opt out is in mine (and others) opinion a really bad strategy. Especially because no-one seemingly are being informed about this aggressive image compression prior to buying the product.

I think that O2 could have introduced the compression “feature” as a cool add-on. Had O2 chosen to enable users to turn it off / on then maybe it would have been more appreciated. Then people could decide themselves what is most important: an aesthetic (normal) experience or to get most internet experience within their data allowance.

Maybe O2 will consider making it configurable some day in the future? For those of you who are affected and bound to a 24 month deal, I sure hope so...

[Update] See fix here.

[Update 2] Fix for O2 iPhones.