High Definition Television (HDTV) Resolution Explained

HDTV’s look much better then standard definition TV’s and the reason is resolution! So it does play an important role in creating a high definition image. High definition televisions are capable of displaying over 1 million pixels and more to create what we call an HD image. If your getting all confused with all the numbers we are sure once your done reading this you will have a good understanding on what all the numbers mean!

Native Resolution: Explained

LCD and Plasma HDTV’s use what we call fixed pixel displays, we call them fixed because they use an un-fluctuating matrix of pixels. And If the input signal is not the same resolution as the display, complex algorithms adjust (scale) the resolution up or down to conform to the display's fixed number of pixels in each row and column.

All LCD and Plasma Television displays have a native resolution specification which tells you the number of pixels the TV actually has. The Native Resolution is the maximum number of pixels which makes up the image details you will see. Today the most common Native resolutions are 720p and 1080p the p is for progressive scan, progressive scan means the picture is being painted in sequence, this is in contrast to the interlacing used on older televisions where only the odd lines then even lines of each frame are painted alternately.

Remember fixed pixel displays will always convert or scale the input signal to fit it’s native resolution, this is where all the confusion begins. Relax we’ll explain it below in detail.

UP-Converting

Okay, If the input signal source (Cable, DVD, blu-ray, etc.) displays more pixels then the displays native resolution loss of visible detail and sharpness will occur. But.. The picture still looks good, just not as sharp, showing slight visible degrading of picture quality is normal in this case.

Down-converting

In-turn, if the input signal source outputs fewer pixels than the native resolution, you will not experience any extra sharpness from your television, nor will the picture be degraded.

Now for perfect harmony! If you input signal source outputs the same pixels as your televisions native resolution your display won’t have to up or down scale the signal resulting in little to no distortion. This is the way to go. But, It’s not as easy as said. Unfortunately every type of signal has a different signal pixel output resolution. EXAMPLE: Standard TV broadcast at 480i, that's 480 interlaced lines of resolution. If you have a 720p or 1080p your set would have to down convert the signal resulting in a decrease of sharpness. Progressive-scan VCR output at 480p that’s 480 progressive lines of resolution. High definition television broadcast output at 720p and 1080i, so if your TV has a native resolution of 720p then you will not have to up-convert most high definition TV channels unless it’s broadcasting in 1080i. Now if your watching a 480i SD channel and your TV has a native resolution of 720p you will be down-converting the signal with little distortion.

High Definition Television Resolutions

Okay, by now you should be getting a little familiar with how HDTV resolution works. As you are starting to see, it’s all about the source! High definition sources currently broadcast in three different resolutions. Starting with the highest 1080p, 1080i and 720p. As you might have guessed 1080i has more lines of resolution than 720p but 1080i is an interlaced signal. 720p is progressive-scan and it shows smoother cleaner images than 1080i when fast motion action scenes are painted. 1080p merges the high quality 1080 lines of resolution like 1080i with the smooth action produced with progressive-scan like 720p resulting in 1080p (1080 progressive scanning lines of resolution). Unfortunately 1080p sources is limited to Blu-ray, some video on-demand services and newer video games systems. Were still waiting on broadcast technology and major networks to catch up with 1080p.

Yet, 1080i and 720p signals deliver great looking HD images and to an untrained eye most won’t be able to recognize the difference between 1080i and 720p.

The big visual difference is between SD signals like 480i and HD signals like 720p or 1080i.

Remember fixed displays always up-convert or down-convert the incoming signal to fit the TV’s available pixels.

1080p, is it worth it?

Okay, now you might be wondering if you should spend the extra dollars to get a 1080p HDTV. Hopefully we can help you weigh the pro’s and con’s.

Below we have a graph to help you decide what native resolution would suite you best.

As Blu-ray Disc storms the market 1080p is becoming a desired native resolution of the many instead of the privileged few. As technology improves we are sure 1080p will become a broadcast standard, when? We don’t know or will begin to pretend we do. But what we do know is that technology catches up, and usually at a high rate of speed.

Resolution output sources

1080p

1080i

720p

480p

480i

1920x1080

Lines of resolution

1920x1080

Lines of resolution

1280x720

Lines of resolution

852x480

Lines of resolution

480 Lines &

Under

Blu-ray Players

Playstation 3,Xbox360 , some on-demand sources.

Networks broadcast in 1080i, Includes: Discovery HD, NBC, CBS, PBS, Animal planet HD, The CW, A&E HD,  The food network HD, Golf Channel HD, HDNet, HGTV and more..

As you see Most Channels Broadcast in 1080i.

Networks Broadcast in 720p, Includes:

ESPNHD, ABC, FOX. Espn 2 Less channels Broadcast in 720p.

Progressive -scan DVD players

Standard Television broadcast

(SDTV), Non-progressive scan DVD players.