Six months after releasing the Samsung Galaxy S3, the biggest selling smartphone of the year, the rumor mill regarding its successor is going into overdrive.

A Korean Web site is saying that the S4 will have a 5-inch Super AMOLED display with 1920x1080 full HD resolution, giving it a pixel density of 441ppi.

That report corroborates rumors which emerged in October which suggested that Samsung and LG were both working on smartphones with a full-HD display and due to be released in the first-half of 2013.

The source of the leak, reported on the website Asiae, says that the Galaxy S4's display is "beyond the limits of the human eye."

The handset is expected to come with a quad-core ARM Cortex-A15 processor built by Samsung itself under the Exynos brand, clocking in at 2GHz, which is by far the most powerful smartphone processor on the market.

The website also speculates that the device will be thinner than the S3, which is itself only 8.6mm thick, due to a next-generation memory chip being developed by Samsung with a far thinner profile than its current-generation parts.

Finally, the S4 is expected to include a 13MP camera on the rear, a massive increase from the 8MP camera on the S3, and will include a powerful autofocus system and the ability to capture full HD video as well as high-resolution stills. With the introduction of a 360-degree panorama mode for the Android 4.2 Jelly Bean update, that feature is also likely to be supported by the camera, as is a high dynamic range (HDR) shooting mode - something seen in an increasing number of smartphones.

The new device won't be the first full HD smartphone on the market. HTC is preparing to release its Droid DNA in the US in December, which promises a 5-inch display, 1920x1080 full HD with a Super LCD 3 screen coated with Gorilla Glass 2 and a density of 443ppi.

Nothing official has been announced by Samsung, although some people expect the new phone will be unveiled either at CES 2013 in January or the Mobile World Congress at the end of February next year.