The launch of HDTV or high definition television represents the most important advance in the specification of broadcasting and TV ever since colour. For a flat panel widescreen tv to receive and benefit from a high definition signal it must have a screen resolution of 1280 X pixels 720 pixels and be labelled HD Ready.
What does 'HD ready' mean ?
For a television to be HD ready and display a HD signal it ought to have a minimum screen resolution of 1280 X pixels 720 pixels, where 720 is the number of vertical lines. It should also be capable to receive a signal of the specification of 720p/50 or 1080i/25; the amount of vertical lines is represented by the 720 and the 1080, Progessive or Interlaced signals are signified by the 'p' or 'i', and the number of frames per second is the 50 or 25. Connection for the HD signal is by either DVI or HDMI and Component inputs.
For a 1366 x 768 pixels HD ready TV, if it receives a 1080i signal then scalers within the flat screen tv will down convert the picture to fit the 768 lines flat screen television. This is done using complex algorithm sequences in the scaler which systematically crops the image down to the resolution of the screen. If the signal is at 720p then the signal will be slightly upscaled to fill the 768 vertical lines using complicated algorithms.
When a Full HD signal (1920 x 1080 pixels) is received by a HD Ready TV one to one pixel mapping is not viable due to insufficient pixels so the picture has to be interpolated to the screen resolution.
What is 'HD ready 1080P' ?
Any TV that carries the 'HD ready 1080p' is naturally capable of displaying a 'full' 1080P signal with sufficient pixels to give true pixel-for-pixel mapping without interpolation. A HD ready 1080p flat panel television has a screen resolution of (1920 x1080 pixels) i.e. 1080P, where '1080' is the vertical resolution of the picture and the 'P' is for Progressive scan. HD ready 1080P is the highest resolution available in the UK on HD televisions hence the 'full' term. These sets can display 1080p and 1080i video without distortion i.e. with 1:1 pixel mapping. They also boast HDMI or DVI HD input at 1080p HD and display signals that are at either 24 or 50 frames per second.
As soon as a 1080p HD tv receives s 720p input it will upscale (or oversample) the signal to the resolution of the 1080p HDTV screen with complex internal software algorithms.
Full HD
Early high definition tv's didn't hold the 'HD Ready 1080p' logo and may well not be compatible with this specification and may not display selected signal inputs.
What is an Interlaced or Progressive picture ?
On an Interlaced Picture the scan lines of a frame are arranged in two fields each. One of the two fields contains the odd lines and the other field holds the even lines. Interlacing is when these two fields are shown in succession at twice the rate of the actual frame and at half the resolution.
When a image is interlaced, moving pictures on video seem to have smoother movement since each field of the frame are shot at different times. The system of picture interlacing was in the first place used to enhance the quality of the picture on CRT tvs using the same amount of bandwidth for the broadcast signal.
Televisions in the UK have a PAL picture system that have a rate of 25 frames per second or 50 fields per second. An Interlaced signal uses half the bandwidth of a Progressive signal i.e. the progressive scanning process needs to scan the picture 50 times per second whilst the interlaced scanning process works at half of that speed.
Interlaced pictures on recordings made for television or with a video camera aren't able to be displayed on normal definition LCD tvs and Plasma televisions. This is because the picture isn't created with an electron scan like CRT televisions so LCD televisions and Plama tvs don't benefit from the interlaced picture signal. Flat screen widescreen tv's have internal processing to create a progressive scanned image from a interlaced picture - i.e. Deinterlacing.
The advantagess of progressive scanning
This is in addition known as non-interlaced scanning. It is a technique of storing, displaying or transmitting a moving picture where all of the lines of every frame are shown sequentially instead of odd lines in one field and then even lines in the subsequent field as per Interlaced signals.
The vertical resolution when the frame rate is the same is greater for a progressive image than it is for an interlaced image and the image is free of interlace artifacts, blurring, and greatly lower eye strain. With a progressive image it can be scaled to a higher resolution than an interlaced image giving a higher quality image. This is due to the deinterlacing that is necessary on an interlaced image preceding any scaling resulting in combing artifacts that are perceptible.
What is the difference between the 720p/50 and 1080i/25 formats?
When a 1080i/25 (1,920 pixels x 1080 pixels resolution) signal displays a still picture the horizontal resolution is marginally better than the 720p/50 (1,280 x 720 pixels resolution) image. When an image moves on an interlaced signal the subjective line resolution is reduced due to line twitter because the two fields that make up the frames are a little different. Depending on the bandwidth availability broadcasters are at present using either 720p/50 or 1080i/25.
Smoother movement is produced with 720p progressive scanned pictures, particularly on slow-motion, compared to 1080i interlaced pictures. Better still images are produced with interlaced 1080i signals. By means of good quality built in processing a 1080i signal will appear superior on a 1080 television compared to a 720p source. The one you ought to choose, will depend on the type of pictures being predominantly displayed, either static or moving, and your preferences.
The conversion of a progressive source such as 1080p/50 into an interlaced configuration such as 1080i/25 is easier than the conversion of an interlaced signal to a progressive format.
What are the advantages of 1080p/24?
The ultimate picture quality is obtainable on films with a 1080p signal at 24 frames per second, when viewed via a BlueRay player on a flat screen high def tv. The frame rate of 24 per second is identical to the original cinema film instead of being increased to 25 frames per second. The internal circuitry in the TV produces added middle frames so that the frame rate is increased to 48 or 72 producing smoother on screen movement.
Sources of High definition.
A HD Ready television can accept all current broadcast formats of 720p/50 or 1080i/25. HD is obtainable on Freesat, Sky Digital HD, BT Vision, and Virgin media cable. The only sources of Full HD 1080P signals are Blueray players, Playstation 3 and by download on the internet. The games on an Xbox 360 are at 720P.
The conclusion
High definition enhances the viewing experience and makes TV more engaging. If you don't plan to use a Blueray player, Playstation 3, or to download films off the internet then a HD ready tv will probably suffice. Then again if you need to future proof yourself against the chance of future full HD 1080p broadcasts then the full HD 1080p models are the ones to purchase. Obviously, if you already own, or are going to buy a Blueray player, Playstation 3 or to you are going to down load full high definition films then the full HD 1080p television is the sensible choice. - 16492
What does 'HD ready' mean ?
For a television to be HD ready and display a HD signal it ought to have a minimum screen resolution of 1280 X pixels 720 pixels, where 720 is the number of vertical lines. It should also be capable to receive a signal of the specification of 720p/50 or 1080i/25; the amount of vertical lines is represented by the 720 and the 1080, Progessive or Interlaced signals are signified by the 'p' or 'i', and the number of frames per second is the 50 or 25. Connection for the HD signal is by either DVI or HDMI and Component inputs.
For a 1366 x 768 pixels HD ready TV, if it receives a 1080i signal then scalers within the flat screen tv will down convert the picture to fit the 768 lines flat screen television. This is done using complex algorithm sequences in the scaler which systematically crops the image down to the resolution of the screen. If the signal is at 720p then the signal will be slightly upscaled to fill the 768 vertical lines using complicated algorithms.
When a Full HD signal (1920 x 1080 pixels) is received by a HD Ready TV one to one pixel mapping is not viable due to insufficient pixels so the picture has to be interpolated to the screen resolution.
What is 'HD ready 1080P' ?
Any TV that carries the 'HD ready 1080p' is naturally capable of displaying a 'full' 1080P signal with sufficient pixels to give true pixel-for-pixel mapping without interpolation. A HD ready 1080p flat panel television has a screen resolution of (1920 x1080 pixels) i.e. 1080P, where '1080' is the vertical resolution of the picture and the 'P' is for Progressive scan. HD ready 1080P is the highest resolution available in the UK on HD televisions hence the 'full' term. These sets can display 1080p and 1080i video without distortion i.e. with 1:1 pixel mapping. They also boast HDMI or DVI HD input at 1080p HD and display signals that are at either 24 or 50 frames per second.
As soon as a 1080p HD tv receives s 720p input it will upscale (or oversample) the signal to the resolution of the 1080p HDTV screen with complex internal software algorithms.
Full HD
Early high definition tv's didn't hold the 'HD Ready 1080p' logo and may well not be compatible with this specification and may not display selected signal inputs.
What is an Interlaced or Progressive picture ?
On an Interlaced Picture the scan lines of a frame are arranged in two fields each. One of the two fields contains the odd lines and the other field holds the even lines. Interlacing is when these two fields are shown in succession at twice the rate of the actual frame and at half the resolution.
When a image is interlaced, moving pictures on video seem to have smoother movement since each field of the frame are shot at different times. The system of picture interlacing was in the first place used to enhance the quality of the picture on CRT tvs using the same amount of bandwidth for the broadcast signal.
Televisions in the UK have a PAL picture system that have a rate of 25 frames per second or 50 fields per second. An Interlaced signal uses half the bandwidth of a Progressive signal i.e. the progressive scanning process needs to scan the picture 50 times per second whilst the interlaced scanning process works at half of that speed.
Interlaced pictures on recordings made for television or with a video camera aren't able to be displayed on normal definition LCD tvs and Plasma televisions. This is because the picture isn't created with an electron scan like CRT televisions so LCD televisions and Plama tvs don't benefit from the interlaced picture signal. Flat screen widescreen tv's have internal processing to create a progressive scanned image from a interlaced picture - i.e. Deinterlacing.
The advantagess of progressive scanning
This is in addition known as non-interlaced scanning. It is a technique of storing, displaying or transmitting a moving picture where all of the lines of every frame are shown sequentially instead of odd lines in one field and then even lines in the subsequent field as per Interlaced signals.
The vertical resolution when the frame rate is the same is greater for a progressive image than it is for an interlaced image and the image is free of interlace artifacts, blurring, and greatly lower eye strain. With a progressive image it can be scaled to a higher resolution than an interlaced image giving a higher quality image. This is due to the deinterlacing that is necessary on an interlaced image preceding any scaling resulting in combing artifacts that are perceptible.
What is the difference between the 720p/50 and 1080i/25 formats?
When a 1080i/25 (1,920 pixels x 1080 pixels resolution) signal displays a still picture the horizontal resolution is marginally better than the 720p/50 (1,280 x 720 pixels resolution) image. When an image moves on an interlaced signal the subjective line resolution is reduced due to line twitter because the two fields that make up the frames are a little different. Depending on the bandwidth availability broadcasters are at present using either 720p/50 or 1080i/25.
Smoother movement is produced with 720p progressive scanned pictures, particularly on slow-motion, compared to 1080i interlaced pictures. Better still images are produced with interlaced 1080i signals. By means of good quality built in processing a 1080i signal will appear superior on a 1080 television compared to a 720p source. The one you ought to choose, will depend on the type of pictures being predominantly displayed, either static or moving, and your preferences.
The conversion of a progressive source such as 1080p/50 into an interlaced configuration such as 1080i/25 is easier than the conversion of an interlaced signal to a progressive format.
What are the advantages of 1080p/24?
The ultimate picture quality is obtainable on films with a 1080p signal at 24 frames per second, when viewed via a BlueRay player on a flat screen high def tv. The frame rate of 24 per second is identical to the original cinema film instead of being increased to 25 frames per second. The internal circuitry in the TV produces added middle frames so that the frame rate is increased to 48 or 72 producing smoother on screen movement.
Sources of High definition.
A HD Ready television can accept all current broadcast formats of 720p/50 or 1080i/25. HD is obtainable on Freesat, Sky Digital HD, BT Vision, and Virgin media cable. The only sources of Full HD 1080P signals are Blueray players, Playstation 3 and by download on the internet. The games on an Xbox 360 are at 720P.
The conclusion
High definition enhances the viewing experience and makes TV more engaging. If you don't plan to use a Blueray player, Playstation 3, or to download films off the internet then a HD ready tv will probably suffice. Then again if you need to future proof yourself against the chance of future full HD 1080p broadcasts then the full HD 1080p models are the ones to purchase. Obviously, if you already own, or are going to buy a Blueray player, Playstation 3 or to you are going to down load full high definition films then the full HD 1080p television is the sensible choice. - 16492
About the Author:
For almost 2 decades Armadeus Cornelius has built a wealth of knowledge in the electrical industry. For more advice and information go to his web site for HD Ready TV. Alternatively you can visit his on-line electrical store for discount on HD Televisions.
