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What is HDTV and how does it work?
WHAT IS HDTV; AND HOW DOES IT WORK
HDTV-high definition television-is a type of televising which has a particularly excellent display of picture. The picture is sharper, with much finer detail and quality. On an HDTV screen, you can see much better detail. How that works, is the screen’s picture is made out of tiny little dots called pixels. Those pixels create the picture. That’s how you can see the images on the screen. HDTV does that in a different way than most other televisions; it uses around two million pixels, making the screen’s picture detailed and very perfected.
Comparison of SDTV and HDTV
(HDTV: high definition television. SDTV: standard television.) SDTV and HDTV are both televisions, that operate and display completely differently. For starters, HDTV, as I said before, uses about two million pixels to create a finer picture. SDTV uses only around five hundred thousand pixels, four times less than HDTV, which means a worse picture quality.HDTV gives a much better picture because it can breakdown the picture into more pixels, giving it more quality and aspect. Also, the way that HDTV operates is much different than SDTV.
Usually, old TV’s don’t display the screen as soon as you turn it on. It builds up the picture one line at a time. During this process, the viewer would see the TV building the picture. SDTV does something a bit different; it “cheats” and scans three hundred lines, then later, another three hundred lines. That process is called interlacing. SDTV uses that, but that causes the screen to flicker when it gains lines and fine points. HDTV uses a different method, called progressive scanning. HDTV’s use about one thousand lines, rather than three hundred. The television stores the lines together,and displays the picture all at once after loading. Progressive scanning doesn't make the screen flicker, and is even more in depth because of the extra lines. Overall, the HDTV is much more defined and efficient than the SDTV, and loads the pixels in a different process.
On the left is an example of how many pixels could be on an HDTV screen, and on the right side of the picture; SDTV. You can see how many more pixels HDTV has. That makes HDTV's screen quality better, and more detailed than the SDTV.
Color Classification Systems
Some examples of classification systems are The Optical Society of America Uniform Color Scales and the Swedish Natural Color System. The NCS system organizes different colors based on perceptions. Each color has four perceptions like; purple may have white, black, red and blue within it. You can assign percentages to each perception. Having the different percentages for each picture on a screen could change how the entire screen looks. With different percentages on each pixel, the picture would look extremely detailed. Another system, called The Munsell system is used to arrange colors into three different groups; hue, value and Chroma Hue is basically the same as color, such as, red, blue and green. This system arranges the hue (colors) into categories. The categories are yellows, green-yellows, greens, blue-greens, blues, purple-blues, purples, red-purples, reds, and yellow-reds. Chroma tells you how much of one color is in each whole color. Value is defining the light and darkness in a color, or the shade. Colors vary in hue, value and Chroma The more variety to each of the three, the more complex and detailed the picture on the screen will come out looking.
There are many color classification systems, but the one displayed above is The Munsell System. The picture displays different types of hue.
History of the HDTV
By the time 2007 came, at least one hundred million television homes were using HD programming on their TVs. About sixteen million HDTV sets were sold that year. Prices were dropping, and the technology was continually evolving. This made people want the televisions even more. Lots of television channels air shows with HD programming, and movies on demand were broadcasted in association with HDTV. Some major channels that use HDTV are ABC, CBS, Fox, NBC, and PBS. More and more people are wanting to watch HD programs as time went on.
HDTV- high definition television
SDTV- standard definition television
Pixels- an area of illumination on a display screen, one of many from which an image is composed.
Interlacing-the process of binding intricately together; interweave. (In this case it would be lines being interlaced on a television screen.)
Progressive Scanning- a way of displaying, storing, or transmitting moving images on a screen, in which all of the lines of each frame are drawn into a sequence.
Hue- a color or shade.
Value- the lightness or darkness in a color.
Chroma- the purity or intensity of a color.
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Woodcock, Jon and Woodford, Chris. Cool Stuff Two Point Zero And How It Works.New York: DK Pub., 2007. Print.
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