It's no secret that the video processing built into most displays - be they projectors or flatpanel - is a compromise, dictated by pricing. In this competitive marketplace, manufacturers will shave off as much cost as possible and advanced video processing (which is not quite as sexy to would-be buyers as impressive-sounding contrast ratio, brightness and resolution specifications) is often the first to go.

Consequently, much of the really interesting work in processing is not being conducted by the large manufacturers. Instead, it tends to be the domain of specialist developers like Gennum, Faroudja and Silicon Optix. These companies then license their technology to bigger brands.

If you don't want a new display, though, there's another way of being able to benefit from cutting-edge processing - and that's to use an external scaler. These boxes contain specialist technology, and effectively replace the 'front-end' of your existing display.

The name is actually something of a misnomer - they have several functions. The typical scaler will select from several different sources, allow you to make adjustments to the picture and deinterlace your video (assuming its interlaced in the first place) before it scales the picture to match the native resolution of your display.

It's the latter two areas in which the aforementioned specialist developers excel. The overall result can be a dramatic improvement in picture quality from one or more sources, subject to the pedigree of the kit you're partnering it with.

Gennum contributes its VXP processing to Themescene's 1080p-capable HD3000 scaler, which is not dissimilar to the 'controller box' that accompanies the display manufacturer's HD81 1080p DLP projector.

The HD3000 is a neat and low-profile box that leaves you with no doubts as to the exemplary quality of its construction. Top marks to the convenient front-panel AV inputs (composite, S-video and PC RGBHV) that sit with basic menu-driving controls behind a solid flap.

Inputs aplenty

Also noteworthy is the sheer variety of inputs on the rear panel - two composite, two S-video, two component and two RGB (which can be configured for component - or Scart-type RGB and composite sync).

There's only one HDMI input, but the HD3000 includes an in-built three-way HDMI switcher. This operates independently of the processor itself. The HD3000 also gives you two programmable 12V triggers for motorised screens.

There's only one video output, and it's HDMI. The lack of analogue outputs means that owners of HD-capable tubed projectors should look elsewhere. This is very much a video-centric controller. Unlike competing models such as the Vantage HD or Crystalio II, the HD3000 has no audio connectivity, and thus no ability to delay the audio to compensate for video processing times - something that can manifest itself as lip-sync errors. But most serious AV amps have adjustable input delays nowadays.

Setting up the HD3000 won't give enthusiasts any sleepless nights. The 'system' menu offers a choice of resolutions and refresh rates for the (progressively-scanned) output. They include 50Hz and 60Hz variants of 1280 x 720 (720p), 1366 x 768 (WXGA - as specified by many LCD and PDP TVs) and 1920 x 1080 (1080p). There is, alas, no custom mode here for non-standard formats.

Five banks of output video settings - including 'day' and 'night' modes for ISF-certified calibrators - can be independently configured, stored and recalled. Among the parameters here are gamma, colour-temperature, noise reduction, contrast, edge enhancement, brightness, hue and saturation.

Then there's the input video processor, which will adjust settings like colour level, white/black level, noise reduction and hue. Different banks of settings are memorised for each input and signal type. Note that no manual control over deinterlacing parameters is given.

The backlit handset lets you activate many functions without recourse to the menus, which proved most welcome. Each input has its own source-select button. There are six buttons that jump to various aspect ratios. The five aforementioned preset output modes can also be brought into effect at a whim.

Overall, this scaler does a fine job, although the improvements you can expect will ultimately depend on how good your other equipment is.

The adjustments on offer go way beyond what you'll find on most sources and displays - you can thus tweak to your heart's desire until you get the best possible picture.

With a Panasonic DVD recorder configured for 576i, I noted that the HD3000 yielded improved clarity (notably in background detail), enhanced colour depth and smoother movement (the BBC News 24 'ticker' and horizontally-scrolling credits are a good test here) than the recorder's own upscaling modes.

Self-made DVDs also benefit, the HD3000's noise-reduction managing to reduce artifacts without significantly penalising the definition of trickier textures. After swapping to Arcam's DV139 I found that improvements were harder to see.

In the HD realm, there proved to be a discernible visual benefit in processing the 1080i HDMI output of a Sky HD box - noise, in particular, became less of a problem.

I then tried a Toshiba HD-XE1 HD DVD player, with the new Silicon Optix HQV hi-def benchmark amongst other things. Here, the sample HD3000 was found to fail the film resolution-loss test (revealing, theoretically at least, that movie-derived material would be compromised in terms of vertical definition). A second sample fared no better.

Subjectively, though, there appeared to be little deterioration; indeed, the gamma tweaks and other adjustments can benefit the displayed picture - you can, for example, see more 'in the shadows' on occasions, giving the impression that dynamic range has been expanded somehow.

So far, I've concerned myself only with HDMI. Analogue inputs fare well, but there is some inevitable degradation relative to the 'all digital' route. There's little you can do about this, other than use HDMI whenever you can.

The lack of an audio delay function didn't really affect real-world performance - clearly, this processor is fast. Optoma told us that the HD3000 is popular with gaming enthusiasts for this reason.

Overall, the HD3000 is an interesting box of tricks that can help you to make the most from your video. It's well worth comparing with some of the other scalers out there and could add the final touch of polish to your system.