Picture Size And Resolution - JVC LT-19HA22U Mode D'emploi

Picture size and resolution

Resolution and picture quality
Broadcast wide screen films in different resolutions. The following table shows the resolution options for
wide screen film broadcast media.
Resolution of the wide
screen signal
432i x 704 (Letterbox)
576i x 704 (anamorphic)
720 x 1280 (HD)
1080i x 1920 (HD)
* Digital Cable receiver with HDMI output required.
Best picture quality is achieved when the input signal has a resolution of 1920 x 1080i. If a signal with a lower
resolution is input (e.g. analogue cable TV), there is a visibly poorer picture quality.
This is understandable as, if the same picture quality were available at a lower resolution, the broadcasting
companies would not need to take the trouble to send the signal at the higher resolution.
Why are there different resolutions?
Analogue cable TV uses a standardised TV signal. Each analogue tube TV, however old it is, can process this
signal. That is the advantage of standardisation. The disadvantage is that the resolution has not changed since
the end of the Second World War. The resolution has been max. 576i x 768, or approx. 0.4 megapixels, for over
60 years. In comparison, modern cameras typically have a resolution of 12 megapixels, e.g. 4000 x 3000.
Why do cameras have high resolutions of 12 megapixels and more?
Photos are for printing. 0.4 megapixels are far too few for a good A4 picture. Even the most expensive printer
cannot make a good A4 picture from 0.4 megapixels.
For the same reason HD-TV sets cannot display a good picture from the signal of an analogue cable TV. 16:9
programmes have black frames. The resolution is only 432 x 704. That corresponds to 0.3 megapixels – far
too few for HD-TV sets!
Digital cable TVs show 16:9 programmes without black frames. Vertical resolution is increased from 432 lines
to 576 lines. This alone already gives a visible picture improvement. A digital cable receiver is necessary for
receiving digital cable TV. Please ask your cable provider.
A digital cable receiver with HDMI output allows HD-TV reception of the optimum HD signal at a resolution of
1920 x 1080i.
Picture quality and black bars
Wide screen films come in different formats. The format is the relationship
between the width and height of the picture. For example, with a 16:9 film
the width to height ratio is 16:9 or 1.78:1. Only 16:9 films can fill a HD-
ready screen without black bars. Therefore, black bars are always visible
when a format other than 16:9 is received. E.g. 4:3, A 4:3 displays vertical
black bars to the right and left.
If a 4:3 picture is increased to 16:9 format then it either appears distorted
(see illustration) or some parts of the picture are cropped off at the top and
the bottom. This is completely normal and is not a fault in the wide screen
TV.
Super Cinemascope films are wider than 16:9 films. They are in the format
2.4:1 or 22:9, for example. This is clearly wider than16:9. Therefore, Super
Cinemascope films display black bars at the top and bottom on any HD-
ready TV set.
Picture format and resolution
There is no connection between the picture format and the resolution received. For example, the Super
Cinemascope format can be received in all resolutions, even in the HD resolution1080ix1920. For HDTV
reception too an HD-ready set may display black bars at the top and bottom.
Broadcast media
Analogue Digital
cable TV cable TV
Yes Yes
No Yes
No Yes*
No Yes*
DVB-T Satellite DVD
(DVB-S)
Yes Yes Yes
Yes Yes Yes
No No No
No No No
HDTV Blu-ray-
Satellite Disc
(DVB-S2)
Yes No
Yes No
Yes Yes
Yes Yes
4:3 picture 1:1 on
16:9 screen
4:3 picture zoomed on
16:9 screen
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