The Design Basics
Apologies for the delay in this post. It was a very busy few weeks of IBC 2006, Amsterdam.
Here are some basics of TV environment that will ready a designer for his next task - Design!
The TV Resolution:
NTSC Format: 640 X 480 pixels
PAL Format: 720 X 576 pixels
HDTV Format - 1280 X 720 pixels
These dimensions are full dimensions inclusive of safe area. Generally its good to assume 20% on all sides as a safe area. In case of PAL TV this dimension brings the actual viewable resolution to 576 x 440 pixels.
Pixels on TV:
The shape of TV pixels is a little bit rectangular. Its not a perfect square. For designers who design the TV user interfaces using Photoshop as a standard tool, please be sure to use "Image/Pixel Aspect Ratio/ " option to select the correct format you are designing for. If that is not the case, most of your designs will look different on TV than they look on your PC. For example if you have a circular object in your design, it will appear oval in actual on TV.
Interlacing:
Our generic computer screens use progressive scan - each frame is made up of the entire screen area from top to bottom.
On a CRT television set, however, each frame is made up of two fields that are interlaced. This makes thin horizontal lines vibrate or flicker.
TV sets that use plasma or LCD technology convert the interlaced picture to progressive frames before displaying them. (more details can of course be found on the eternal source -Wikipedia)
However LCD and HDTV technologies are still at their beginning and most users are still using TV's that use CRT technology. Thereby, the designer is now challenged with two sets of design - One for CRT format which is 4:3 resolution and one for HDTV format which is 16:9 resolution.
Color and Contrast modes on TV:
The range of colors is limited on TV's. However this trend is now changing fairly quickly. A designer should although be strongly aware of the color mode supported by the destination TV. The mode could be either 8 Bit or 16 Bit or 32 Bit depending on the middleware and the Set-top-box hardware being used.
Navigation Methods on a TV
The primary mode of navigation on a TV is a remote control. Although keyboards and roll mouse buttons have been in existence, remote control still remains the preferred way. The important pieces for a designer to consider here are - up/down/left/right is a "one click at a time" process. Most newer remotes have certain specific buttons for special functions such as bringing up an internet browser etc. The conventions of buttons on a remote are different in the America's and Europe. Hotkeys predominantly rule the way in Europe where as custom keys as needed by the service provider dominate the US interactive TV scene.
Special Effects and Animations
Depending on the type of middleware and the set-top-box being used, the special effects used to generate interactivity may differ.
For example the Microsoft TV UI uses a very fast performance STB with a heavy middleware. Thereby rendering the visual effects very crisp and smooth. However the price to performance ratio is a very critical factor and even though its for the business folks to worry about, it is important that a designer touches the aspects of it. In perspective, the designer should always have all the technical details of the STB and the middleware at hand before proposing performance intensive visual effects.
Here are some basics of TV environment that will ready a designer for his next task - Design!
The TV Resolution:
NTSC Format: 640 X 480 pixels
PAL Format: 720 X 576 pixels
HDTV Format - 1280 X 720 pixels
These dimensions are full dimensions inclusive of safe area. Generally its good to assume 20% on all sides as a safe area. In case of PAL TV this dimension brings the actual viewable resolution to 576 x 440 pixels.Pixels on TV:
The shape of TV pixels is a little bit rectangular. Its not a perfect square. For designers who design the TV user interfaces using Photoshop as a standard tool, please be sure to use "Image/Pixel Aspect Ratio/ " option to select the correct format you are designing for. If that is not the case, most of your designs will look different on TV than they look on your PC. For example if you have a circular object in your design, it will appear oval in actual on TV.
Interlacing:
Our generic computer screens use progressive scan - each frame is made up of the entire screen area from top to bottom.
On a CRT television set, however, each frame is made up of two fields that are interlaced. This makes thin horizontal lines vibrate or flicker.
TV sets that use plasma or LCD technology convert the interlaced picture to progressive frames before displaying them. (more details can of course be found on the eternal source -Wikipedia)
However LCD and HDTV technologies are still at their beginning and most users are still using TV's that use CRT technology. Thereby, the designer is now challenged with two sets of design - One for CRT format which is 4:3 resolution and one for HDTV format which is 16:9 resolution.Color and Contrast modes on TV:
The range of colors is limited on TV's. However this trend is now changing fairly quickly. A designer should although be strongly aware of the color mode supported by the destination TV. The mode could be either 8 Bit or 16 Bit or 32 Bit depending on the middleware and the Set-top-box hardware being used.
Navigation Methods on a TV
The primary mode of navigation on a TV is a remote control. Although keyboards and roll mouse buttons have been in existence, remote control still remains the preferred way. The important pieces for a designer to consider here are - up/down/left/right is a "one click at a time" process. Most newer remotes have certain specific buttons for special functions such as bringing up an internet browser etc. The conventions of buttons on a remote are different in the America's and Europe. Hotkeys predominantly rule the way in Europe where as custom keys as needed by the service provider dominate the US interactive TV scene.Special Effects and Animations
Depending on the type of middleware and the set-top-box being used, the special effects used to generate interactivity may differ.
For example the Microsoft TV UI uses a very fast performance STB with a heavy middleware. Thereby rendering the visual effects very crisp and smooth. However the price to performance ratio is a very critical factor and even though its for the business folks to worry about, it is important that a designer touches the aspects of it. In perspective, the designer should always have all the technical details of the STB and the middleware at hand before proposing performance intensive visual effects.
posted by AT at 10:04 AM
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