If you pay ITV for access to HD via their hub, then it should play in HD but seeing as though your question is about their app functionality you'll probably be better off asking ITV themselves that question because the app is native to all Youview and Freeview boxes and not provided by...
Time Based Arts
I am trying to upgrade the ITV HUB to ITVX but to no avail. I see there are many. many messages on here about this. Rather than spend hours searching
British TV shows are some of the most popular in the world, and viewers now have a variety of ways to watch them online. Some services, likeBBC iPlayerandITV Hub, allow viewers to watch shows live or on-demand. Others, like 4OD, let viewers download or record content for later viewing...
moving into his first senior role responsible for service management as ITV Head of Transmission. Ian is now responsible for managing the Operations teams in ITV's supply chain, from scheduling through to distribution, working with a number of key partners such as Arqiva, BT, and Red Bee. ...