The introduction of HDTV or HD television signifies the most significant development in the specification of broadcasting and TV ever since colour. For a flat panel widescreen television to receive and gain from a HDsignal it must have a screen resolution of 1280 x pixels 720 pixels and be labelled HD Ready.
What makes a Television 'HD Ready' ?
If a flat screen television carries the HD Ready label it will function with a HD signal and will be able to show a HD picture. televisions that are specified to meet the necessities of the HD Ready logo must have a minimum picture resolution of (1280 pixels x 720 pixels) i.e. 720 vertical lines in 16:9 widescreen, where the signal received is either 720p/50 or 1080i/25 picture formats and to be capable of accepting HD - the '50' or '25' is the quantity of frames per second. They must also able to accept HD inputs by either DVI or HDMI and on Component Inputs.
If a HD Ready television has a screen resolution of 1366 pixels x 768 pixels it will use internal scalers that will convert the signal down to 768 vertical lines when it receives a 1080i signal. With a 720p signal the TV has to upscale the picture (or oversample) to 768 vertical lines. These processes are carried out using advanced software that either crops the imageor oversamples the image to fill the screen.
If a HD Ready television receives a full HD signal of resolution 1920 X pixels 1080 pixels the picture signal has to be interpolated or altered down to display the image. One to one mapping of the pixels is not feasible.
'HD Ready 1080p' - What is it ?
If a plasma television or lcd television has a 'HD ready 1080p' badge it has sufficient pixels to display the full 1080p signal with pixel for pixel mapping with no interpolation. A 1080p flat screen lcd tv or plasma television is 1920 x pixels 1080 pixels where the 1080 is the vertical resolution and the 'p' is for progressive scan. A HD Ready 1080p widescreen lcd television or plasma television is the highest screen resolution in the UK for high definition and hence the term 'full'. Any plasma tv or lcd tv with this resolution can display 1080i and 1080p signals without up or down scaling, and with one to one pixel mapping. Connectivity ought to be by either HDMI or DVI inputs. HD Ready 1080p full hd televisions must be able to display a 1080p/24 or 1080p/50 signal where the 24 and the 50 correspond to the amount of frames per second.
If a 720p signal is received by a 1080p tv it is oversampled (or upscaled) to fill the resolution of the 1080p hi def TV by means of sophisticated software.
Full HD television - What is it ?
Before the HD ready 1080P specification was established some flat screen televisions were described as Full HD. These sets may not be compatible with the HD ready 1080P standard and may not display some inputs.
Interlaced or Progressive
Interlaced picture have two fields that are alternated to create a frame where every other line is shown on each frame. Accordingly the odd lines are on one field and the even lines are on the other field. When the two fields containing the odd and even lines are displayed consecutively for each frame at double the frame rate this is known as Interlacing.
One of the advantages of Interlacing is that when footage is shot of a moving image each of the fields of a frame are taken at different times making movements that appears more fluid. Picture Interlacing is a procedure that was originally used to improve the picture quality of a signal on CRT tvs without using extra signal bandwidth.
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 operates at half of that speed.
Standard definition LCD televisions and Plasma tvs displays aren't able to operate on an interlaced mode for footage shot with a TV or video camera. Because LCD tv displays and Plasma tv displays do not have an electron scan to create an image they cannot benefit from interlacing. So internal processing in the flat panel tv creates a progressive scan image from the interlaced signal.
Progressive scan delivers benefits.
This is also known as non-interlaced scanning. It is a technique of storing, displaying or transmitting a moving picture where all of the lines of each frame are shown sequentially instead of odd lines in one field and then even lines in the subsequent field as per Interlaced signals.
Progressive scan has the benefit of superior vertical resolution than interlaced images with the same frame rate and no interlace artifacts or blurring, and hence less eye strain. Also better results are possible for scaling to higher resolutions than the equivalent interlaced sources. For the finest scaling results full frames work the best but interlaced video sources have got to be deinterlaced before being scaled and this can produce extremely noticeable combing artifacts.
The differences between 720p/50 and 1080i/25 formats
When a 1080i/25 (1,920 x 1080 pixels resolution) signal displays a still image the horizontal resolution is marginally better than the 720p/50 (1,280 pixels x 720 pixels resolution) picture. When an image moves on an interlaced signal the subjective line resolution is reduced due to line twitter for the reason that the two fields that make up the frames are slightly different. Depending on the bandwidth availability broadcasters are at present using either 720p/50 or 1080i/25.
Progressive scanning 720p gives more fluid movement, particularly on slow-motion, than an interlaced 1080i signal. But interlaced 1080i signals give better static resolution. If the internal processing is competent enough a 1080i signal on a 1080 display will still appear better than the 720p material. The best one depends on whether you are to display more static pictures or more moving pictures and what is more important to you.
When a HD Ready tv receives a 1080p/50 signal it can change the picture into a 1080i/25 image much easier than a full HDTV can change a 1080i signal into 1080p.
What are the advantages of 1080p/24?
The definitive picture quality is available on films with a 1080p signal at 24 frames per second, when viewed via a Blu Ray player on a flat panel 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 television produces extra middle frames so that the frame rate is increased to 48 or 72 producing smoother on screen motion.
Sources of high def.
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 Blu ray players, Playstation 3 and by download on the internet. The games on an Xbox 360 are at 720P.
In conclusion
HD enhances the viewing experience and makes TV more engaging. If you don't expect to use a Blu ray player, Playstation 3, or to download films from the internet then a HD ready television will probably suffice. Then again if you would like to future proof yourself against the chance of future full high definition 1080p broadcasts then the full HD 1080p models are the ones to buy. Clearly, if you already have, or are going to buy a Blu ray player, Playstation 3 or to you are going to down load full high definition films then the full HD 1080p tv is the sensible choice.
What makes a Television 'HD Ready' ?
If a flat screen television carries the HD Ready label it will function with a HD signal and will be able to show a HD picture. televisions that are specified to meet the necessities of the HD Ready logo must have a minimum picture resolution of (1280 pixels x 720 pixels) i.e. 720 vertical lines in 16:9 widescreen, where the signal received is either 720p/50 or 1080i/25 picture formats and to be capable of accepting HD - the '50' or '25' is the quantity of frames per second. They must also able to accept HD inputs by either DVI or HDMI and on Component Inputs.
If a HD Ready television has a screen resolution of 1366 pixels x 768 pixels it will use internal scalers that will convert the signal down to 768 vertical lines when it receives a 1080i signal. With a 720p signal the TV has to upscale the picture (or oversample) to 768 vertical lines. These processes are carried out using advanced software that either crops the imageor oversamples the image to fill the screen.
If a HD Ready television receives a full HD signal of resolution 1920 X pixels 1080 pixels the picture signal has to be interpolated or altered down to display the image. One to one mapping of the pixels is not feasible.
'HD Ready 1080p' - What is it ?
If a plasma television or lcd television has a 'HD ready 1080p' badge it has sufficient pixels to display the full 1080p signal with pixel for pixel mapping with no interpolation. A 1080p flat screen lcd tv or plasma television is 1920 x pixels 1080 pixels where the 1080 is the vertical resolution and the 'p' is for progressive scan. A HD Ready 1080p widescreen lcd television or plasma television is the highest screen resolution in the UK for high definition and hence the term 'full'. Any plasma tv or lcd tv with this resolution can display 1080i and 1080p signals without up or down scaling, and with one to one pixel mapping. Connectivity ought to be by either HDMI or DVI inputs. HD Ready 1080p full hd televisions must be able to display a 1080p/24 or 1080p/50 signal where the 24 and the 50 correspond to the amount of frames per second.
If a 720p signal is received by a 1080p tv it is oversampled (or upscaled) to fill the resolution of the 1080p hi def TV by means of sophisticated software.
Full HD television - What is it ?
Before the HD ready 1080P specification was established some flat screen televisions were described as Full HD. These sets may not be compatible with the HD ready 1080P standard and may not display some inputs.
Interlaced or Progressive
Interlaced picture have two fields that are alternated to create a frame where every other line is shown on each frame. Accordingly the odd lines are on one field and the even lines are on the other field. When the two fields containing the odd and even lines are displayed consecutively for each frame at double the frame rate this is known as Interlacing.
One of the advantages of Interlacing is that when footage is shot of a moving image each of the fields of a frame are taken at different times making movements that appears more fluid. Picture Interlacing is a procedure that was originally used to improve the picture quality of a signal on CRT tvs without using extra signal bandwidth.
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 operates at half of that speed.
Standard definition LCD televisions and Plasma tvs displays aren't able to operate on an interlaced mode for footage shot with a TV or video camera. Because LCD tv displays and Plasma tv displays do not have an electron scan to create an image they cannot benefit from interlacing. So internal processing in the flat panel tv creates a progressive scan image from the interlaced signal.
Progressive scan delivers benefits.
This is also known as non-interlaced scanning. It is a technique of storing, displaying or transmitting a moving picture where all of the lines of each frame are shown sequentially instead of odd lines in one field and then even lines in the subsequent field as per Interlaced signals.
Progressive scan has the benefit of superior vertical resolution than interlaced images with the same frame rate and no interlace artifacts or blurring, and hence less eye strain. Also better results are possible for scaling to higher resolutions than the equivalent interlaced sources. For the finest scaling results full frames work the best but interlaced video sources have got to be deinterlaced before being scaled and this can produce extremely noticeable combing artifacts.
The differences between 720p/50 and 1080i/25 formats
When a 1080i/25 (1,920 x 1080 pixels resolution) signal displays a still image the horizontal resolution is marginally better than the 720p/50 (1,280 pixels x 720 pixels resolution) picture. When an image moves on an interlaced signal the subjective line resolution is reduced due to line twitter for the reason that the two fields that make up the frames are slightly different. Depending on the bandwidth availability broadcasters are at present using either 720p/50 or 1080i/25.
Progressive scanning 720p gives more fluid movement, particularly on slow-motion, than an interlaced 1080i signal. But interlaced 1080i signals give better static resolution. If the internal processing is competent enough a 1080i signal on a 1080 display will still appear better than the 720p material. The best one depends on whether you are to display more static pictures or more moving pictures and what is more important to you.
When a HD Ready tv receives a 1080p/50 signal it can change the picture into a 1080i/25 image much easier than a full HDTV can change a 1080i signal into 1080p.
What are the advantages of 1080p/24?
The definitive picture quality is available on films with a 1080p signal at 24 frames per second, when viewed via a Blu Ray player on a flat panel 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 television produces extra middle frames so that the frame rate is increased to 48 or 72 producing smoother on screen motion.
Sources of high def.
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 Blu ray players, Playstation 3 and by download on the internet. The games on an Xbox 360 are at 720P.
In conclusion
HD enhances the viewing experience and makes TV more engaging. If you don't expect to use a Blu ray player, Playstation 3, or to download films from the internet then a HD ready television will probably suffice. Then again if you would like to future proof yourself against the chance of future full high definition 1080p broadcasts then the full HD 1080p models are the ones to buy. Clearly, if you already have, or are going to buy a Blu ray player, Playstation 3 or to you are going to down load full high definition films then the full HD 1080p tv is the sensible choice.
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