For a while now I’ve been frustrated with the quality of images downloaded through O2′s mobile network on my iPhone. It seems like O2 heavily compresses any images that goes through it’s mobile network before transmitting it.
As you can see, there’s a significant difference in the quality of the images.
I have recently stumbled upon a fix for this that seems to work (at least for now). In Settings > General > Network > Cellular Data Network, change the APN from idata.o2.co.uk to mobile.o2.uk and change the username from vertigo to bypass
These settings work like a charm for bypassing that awful image compression. Do bear in mind however that pages with lots of images will take longer to loadand your data usage will increase.
You may need to turn your phone off and then on again before the new settings will take effect. Alternatively, you can switch Airplane Mode On and then Off.
Why does O2 do this?
The most obvious reason is so that they can reduce the demand for bandwidth on their network, specially with the recent surge in iPhone users.
It may however be something O2 does for user experience related reasons. Ironic? Well, given the larger size of the uncompressed image files, pages that have a lot of images take longer to load. This is specially noticeable when you’re out of 3G coverage (using GPRS). Try loading the App Store or even the iTunes Store with the compression bypass settings and you’ll find that the page loads with just text to start with. The images (App Icons and Album Art) don’t display until much later than you would expect for a smooth user experience.
Using image compression is therefore definitely an advantage when you want speedy page loads but not so when you want to view pictures.
What irritates me though is that at no point during the process of signing up for an account with O2 was it mentioned that they use heavy image compression on their network, nor do they make it clear that you can opt out of the image compression by using different settings.
What do you think? Should O2 be more open about using image compression on their mobile network?