US retailer Barnes & Noble has announced two new tablets for the UK market – the Nook HD and the Nook HD+.

The aggressively priced devices run a forked version of Android 4.0 and boast HD displays that comfortably one-up similarly priced tablets in terms of pixels per inch.

They're expected to launch in November 2012, and will ship with Nook's app, video, book and periodical stores preinstalled.

Fighting fire with Nook

The 7-inch Nook HD has a starting price of £159 (roughly $260) – the same as Amazon's Kindle Fire HD and Google's Nexus 7. However, it has both of these devices beat in terms of display resolution, boasting a 1440 x 900 display that's unmatched by any 7-inch device currently on the market.

The Nook HD is lighter than its main rivals, too, and Barnes & Noble is claiming that its 1.3GHz processor is 80 percent faster than the Kindle Fire HD's when it comes to graphics processing.

In a final piece of one-upmanship, both the Nook HD and Nook HD+ will feature expandable memory through a microSD reader – a feature that's missing from Amazon and Google's offerings.

Packing in pixels

The 9-inch Nook HD+ is more expensive, with prices starting at £229 ($370).

However, its 1920 x 1280 'full HD' display rivals that of the new iPad in terms of pixel density – the Nook HD+ squeezes 256 pixels into every inch, while Apple's latest slate has a ppi of 264.

That particular spec similarity – and price disparity –is one that Barnes & Noble is keen to emphasise, with the company's CEO William J. Lynch emphasising the iPad connection in an emailed statement.

"We designed our larger format tablet NOOK HD+, because we think there's big demand from customers for a super-light, extremely high quality 9-inch tablet, at half the price of the iPad."