Merry Christmas Mr. Lawrence is one of those titles that, while very relevant to the film it headlines, tells you nothing whatsoever about it. Indeed, anyone browsing late December TV schedules might even be misled into thinking they'd stumbled on a seasonal children's film, one where kindly old Mr. Lawrence is revealed to be none other than the benevolent Mr. Kringle. Hey, let's get the family together on Boxing Day and watch it with a plate of two-day-old sausage rolls and a glass of peach schnapps.

As most of you will know, it's nothing of the sort, and while that title may not reveal anything about the film's tone or content, it does tell you something about the status of its director, Ōshima Nagisa. This is not a hard and fast rule by any means, but it strikes me that if you want to go with a title that keeps your audience guessing until they actually sit down to watch the film (or start scouring through reviews), then it's probably best to be either an indie newcomer or a filmmaker of some clout. Which is how first-time director Darren Aronofsky could make a film whose title was the mathematical symbol for Pi (driving magazine setters everywhere potty in their search for a font in which it was a character), and how after the humongous international success of Alien, Ridley Scott could persuade The Ladd Company and Warner Brothers to spend millions on a science fiction film with the once baffling title of Blade Runner.

Merry Christmas Mr. Lawrence is one of those films whose title is drawn from a line of its dialogue (this is not uncommon – these films even have their own IMDb category), and while I'm not about to reveal where and in what context this particular line is delivered, just know that every time I watch the film and these words are spoken, I end up with tears waterfalling down my face.

Director Ōshima Nagisa made his name in the early 60s as a leading light of the Japanese new wave, flirted with the experimental with works such as Death by Hanging and Diary of a Shinjuku Thief, then came close to being labelled the enfant terrible of Japanese cinema with his sexually explicit Ai no korîda [In the Realm of the Senses]. Merry Christmas Mr. Lawrence was his first English language film (there's something like a 50/50 split between English and Japanese) and his first featuring an international cast. Based on the partially autobiographical novel The Seed and the Sower by South African born writer Laurens Van der Post, the script was written by Ōshima in collaboration with English screenwriter Paul Mayersberg, whose track record includes The Man Who Fell to Earth and Eureka for Nicholas Roeg. The result, in my humble view, is one of the smartest, most exquisitely realised and emotionally compelling films to emerge from anywhere in the 1980s.

Effectively this new Double Play release from StudioCanal (which contains both DVD and Blu-ray copies of the film – I was only supplied the Blu-ray for review) is an upgrade of their DVD from 2005, when they were trading in the UK as Optimum Releasing. You can read my coverage of that release here, which outlines the plot and explains in more detail just why I hold the film in such high regard. With the extra features the same as the earlier disc, the key difference here lies in the new HD transfer, which leads us nicely to...

It's funny how things change. As technology advances, we are forced to intermittently re-evaluate our definition of what constitutes the cutting edge of picture and audio quality. Just ask any long-standing video gamer how long any game that is the current benchmark for top-of-the-line graphics holds on to that spot (ah, Lunar Jetman...). When DVD first arrived it marked a genuine revolution in picture quality for those of us who never got around to buying a laserdisc player, and only later did we appreciate just how much the quality of transfers could vary. Then Blu-ray comes along to spoil the party by setting a new standard for sharpness and picture detail. Except it's not that simple. In the switch from CRT televisions to LCDs and Plamas, DVDs have to now be upscaled to view at even half-decent quality, a process that transforms a line-based image into one constructed from pixels, and how well this works depends on the upscaling capabilities of your player and television, and somewhat less predictably, the disc itself. Some DVDs look superb when upscaled (the US DVD of John Carpenter's In the Mouth of Madness looks glorious on my setup), while others that look fine on a CRT television just don't make the grade on a 42-inch plasma.

Optimum's DVD of Merry Christmas Mr. Lawrence certainly looked good on a CRT screen back in 2005, and at the time was a real improvement on the previous cropped DVD release. But what was good for DVD back then now inevitably gets judged against what current HD transfers (or, indeed, what DVD's transferred from restored HD masters) are able to deliver, and upscaled to a plasma the Optimum disc doesn't look quite as impressive as it once did. Of course I am being a little unfair here, having watched the Blu-ray first and them popped the older DVD into the adjoining machine for a side-by-side comparison. And it's a comparison worth doing, as while not the most pristine HD transfer I've seen, this new Blu-ray disc of Merry Christmas Mr. Lawrence is still a significant improvement on that previous DVD, and not just in the expected area of higher visible detail – the colours are bolder (this is especially evident in the country garden flashback, which appears washed out by comparison on the DVD) and the contrast is punchier, though in some night scenes this has been graded down to allow a far higher level of shadow detail than is visible on the earlier release. Grain is certainly evident, as it tends to be when the picture is this much sharper, but oddly enough seems less pronounced on some shots (the white sky in panning shot of the jeep at the start of chapter 2) than it is on the same image on the DVD. As so often, it's in facial close-ups (the upward angled shot of Yonoi at the start of the climactic confrontation about the weapons and munitions experts is a fine example) and detailed wide shots that the resolution increase really makes itself known.

You can chose between DTS-HD Master Audio 5.1 surround and LPCM stereo soundtracks – both boast an impressive clarity and a decent dynamic range, but while there is a pleasing spatial feel to the DTS track, the sound sits almost exclusively at the front, with only elements of Sakamoto Ryuichi's astonishing score making use of the full sound stage. The low frequency bass is also more aggressive on the DTS track, providing some subwoofer rumble to the music, but sometimes at the expense of dialogue clarity. The DTS track has more punch, but overall I preferred the LCPM track.

The included extra features are exactly the same as those on the previous DVD, which you can once again read about here.

All are worthwhile, particularly the documentary The Oshima Gang and the interviews with Jeremy Thomas and Sakamoto Ryuichi, but all have been ported over at the same quality as they were on the DVD, complete with the sometimes intrusive background hiss. It may well be a rights issue, but it's also a tad disappointing that we still only get a 10 minute extract from the Scenes at the Sea documentary instead of the full thing.

A still marvellous drama of cultural conflict and kinship that boasts terrific performances, a killer music score, and enough thematic material and subtext to fill a small book. The remastered transfer is a notable improvement on Optimum's previous DVD release, and that was pretty damned good for its day – a shame that the same extras have been recycled instead of being enlarged on or even remastered. If you don't have the DVD then they are all still worth having, even in their slight fuzzy, low resolution state. If you do then the decision to purchase will be based solely on the picture and sound upgrade, and fortunately they both deliver. For the film and the transfer, the disc comes warmly recommended, and if you don't already have the DVD then it's an absolute must-have.