Technology
UncoveredTechnology
Uncovered
Modern Electronics usually come with confusing 'specifications' and extremely difficult technological terms and abbreviations. We try to keep things as simple as possible but some enjoy learning more about the jargon, the meanings, and the advances for the future. We hope you enjoy our collection of current hot topics.
High definition - Hi Def - HDTV stands for High Definition Television, the higher-resolution television of the future.
Standard definition - SDTV stands for Standard Definition Television, which is the basic PAL resolution here in the UK.
Resolution, Definition and Pixels
Analogue PAL TV pictures in the UK are made up of 625 horizontal lines, of which only 576 are for the final displayed picture. Conversion to digital video created required optimum screen resolutions of 720 x 576 dots or 'Pixels' to show the same 4:3 picture shape. Those who are good at maths may say "Why not 768 x 576 pixels?" which is the correct 4:3 ratio? Modern day Pixels are square in shape but older television dots were never square, so the actual digital screen resolution required is only 720(square pixels) width x 576 height. With the introduction of Widescreen pictures the standard PAL screen resolution required is 1024 x 576 square pixels, keeping with the 16:9 widescreen ratio. Standard Computer screens use 640 x 480, 800 x 600, 1024 x 768 pixels, or higher, but 'ratio conversion' means that they are able to show any shape TV picture, but obviously if you convert to a different resolution you can begin to lose picture quality or even stretch the picture out of shape.
HDTV is all about more pixels to provide more detail and definition. Keeping the 16:9 format the true High Definition resolution is 1920 x 1080 pixels. However, it has been agreed that a reduced 16:9 picture made of 1280 x 720 pixels can be described as High Definition.
Anyway, now we can make some understanding of technical data> 1080i and 720p HDTV video formats. Additionally, "p" stands for "progressive" and "i" for "interlaced" images which is a little more technical so to keep simple- a Computer screen uses 'progressive' to load a picture while Tube TV's use Interlaced method. Its hard for the human eye to tell the difference so the main point is, a panel/screen that has 1920 x 1080 pixels will have more definition than a panel that only has 1280 x 720 pixels, both have more than a Standard Definition TV at 720 x 576 pixels.
HD Ready & HD Compatible
Other in-between screen sizes need to process input signals further to create a final display. 852 x 480 resolution screens are common with Plasma & older LCD panels, but since they do not have as many 'dots' to create the picture they cannot be as defined as a standard TV and certainly not good enough to display HD pictures. However, some low resolution flat panel TV's can be 'HD Compatible' by offering HD connection inputs with an in-built processor to convert the picture signal into a display, but with reduced quality it certainly isn't anywhere near true HD.
<< This picture shows the look of a High Definition HDMI connection, which you will find on the rear of HD Ready screens. The component sockets shown are usually included on many screens, along with the very well known 'Scart' sockets, but these are only used for SD equipment.
PAL, MPEG4 and MPEG2
Simply, PAL is the old analogue TV signal which then evolved into 'Digital TV' with the use electronic digitising and a compression of signal, known technically as MPEG2 or PAL MPEG2. HDTV signals will use 'MPEG4' which is an improved modern compression process for digital television, a successor of MPEG2.
