There's no secret which feature of the HTC One (M8) has been pushed to the forefront of the company's marketing for the device most, the Duo Camera. Like with last year's model, HTC has been most proud of its device's photo-taking abilities and it seems that trend will continue with next year's model too.

If naming convention remains, what could well be called the HTC One (M9) will continue the trend of HTC camera improvements, and it is very likely that the main draw in that respect next time out will be the addition of optical zoom.

READ: HTC One (M8) review

In an interview with Vodafone, HTC's imaging specialist Symon Whitehorn said that it is the company's goal to replace a "big camera" as well as compact cameras in the eyes of its customers.

"We already outperform a lot of compact point and shoot cameras, but we want to approach the performance of regular cameras. Every generation of our cameras seems to close that gap," he said.

"What will happen is that we’ll take over more and more of those daily roles, and make it harder to justify taking out a big camera. That’s already happened with the compact camera market."

To do that, Whitehorn explained, HTC would need to improve the optics on its flagship phones, adding optical zoom abilities along the way.

"Optical zooming in a smartphone is not too far off at all for HTC. I can’t give too much away, but within 12-18 months we’ll see huge advances in phone optics," he said.

"“Two years ago I would have said that phones will never replace DSLRs. Now I’m not so sure."