By Roy Ping - CTO, Helios Labs
The home theatre environment has certainly come a long way over the past 60 years. Back then, the typical home theatre experience involved the entire family huddled around a black and white analogue set in the living room, watching the same TV programme as every other person in the country. It certainly is an archaic concept to most of us nowadays when, thanks to recent technological advancements, we can enthusiastically devour cinema theatre-quality experiences in the comfort of our own private spaces.

Enter the HD experience
The advent of high definition (HD) technology has resulted in HD TVs becoming a feature of our domestic spaces. 15% of homes in the United States have an HDTV, with numbers growing steadily. As the insatiable appetite for the HD experience grows, the consumer market is expanding from niche to mainstream. But misconceptions surrounding the technology and capabilities of the product still abound.

The misconceptions
As a manufacturer of HD DVD players, we understand about consumers' desires to reap all the benefits their HDTV’s promise. Some of the most frequently asked questions asked are: 'What resolution should I choose from my DVD player that is best suited to my LCD TV?' 'Will 1080i work well on my TV?' 'How can I get the best high definition resolution from my TV?'
We have also noticed some misconceptions that have come into play. One common mistake is to wrongly interpret HDTV specifications that read something like 'This TV supports 720p and 1080i high definition video input' as meaning that the HDTV will support 720p and 1080i resolutions. The truth is, very few HDTV screens have a 'native' resolution that can match 1080i.
The thing to note is that each LCD, plasma and DLP TV has its own native resolution. To answer the above questions therefore, we must first find out what the 'native resolution' of your TV is. Older- generation plasma TV screens, for example, only have a resolution of 852 x 480, while the new generation plasma TV screens have a higher resolution of 1024 x 1024.

Video signal conversion
The diagram below shows how the video source, such as a DVD player, talks to the HDTV to play images in the analogue domain.

Caption - Video output scaled to match TV display resolution.

Step 1
The video source will output a resolution signal that is different to the HDTV's native resolution. 
Step 2
This video signal passes through a video processor called a scaler. This scaler is a processing chipset that upscales or downscales the received video signal to match the native resolution of the HDTV's screen.
Step 3
The scaler sends this processed signal to the screen to display the image in the TV's native resolution.
When content from a video source, such as a DVD player, is output to a scaler, the original digital format is decoded first by the player, then sent in an analogue format that can be read by the scaler. With that already decoded information, the scaler 'upscales' or 'downscales' the signal and then outputs it to the HDTV, based on the screen's resolution.

Choosing the right video source
While many HDTVs now on the market claim to support 1080i resolution, you will not be able to play your DVD titles in 1080i resolution on these TVs. The key to getting the best images possible out of your HDTV is to choose the right video source - one that can output the exact same digital signal as the resolution of your HDTV's screen, direct from the video source into the HDTV, bypassing the 'scaler'.
Skipping the scaler step is one way of getting a sharper, crisper image from your HDTV. By removing this one step, the digital video signal, in its original format, is sent directly from your video source into your HDTV. DVD players that are able to do so are those equipped with HDMI (High-Definition Multimedia Interface). It is this HDMI feature that takes advantage of a DVD player's ability to upscale or downscale the DVD title according to the HDTV's native resolution. 
HDMI is the new standard for 'pure digital' connection, and was designed as a common interface for devices from set-top boxes to digital TVs. Currently, HDMI offers the best video quality on the market - far better than if an analogue scaler were used to process the signal. 
Thus, the key to getting the most out of your HDTV is finding out your display panel's native resolution, then matching your video source's HDMI output to this specific resolution. DVD players with the HDMI function will allow you to choose from a number of resolutions for matching purposes. Not all DVD players on the market, however, offer a wide range of choices. So if the native resolution of your particular screen is not available from the list of choices on the DVD player, the best thing to do is opt for the next nearest resolution, whether it is slightly higher of lower, and then test by trial and error to see which of the two images appears sharper.
DVD players that offer a large choice of resolution-matching options are the HELIOS line of high-definition upscaling DVD players and high-definition Network Media Players which have the widest range of output and resolution options in the market today. Indeed, owners of DVD players that offer a large choice such as this, have a higher chance of getting the right match for their HDTVs, and are able to reap the benefits from a larger pool of HDTVs available, no matter what the brand, model or resolution.