If you have a video running in standard definition, something like x and you want to display it on a screen that is a higher resolution like x the image needs to be scaled to fit the display. The image is taken from having rows of pixels and making it have rows of pixels and the number of columns is adjusted proportionately.
If scaling wasn't done the video would only fill up a small portion of the larger screen. It would still only take up out of the rows of pixels. Scaling is done all the time without us even thinking about it.
Computer monitors and HDTVs have built in scalers to scale any signal that isn't sent at the display's native generally maximum resolution. If they didn't we'd run into a lot of problems like the one i just mentioned. What your TV does is take that lower resolution signal and it scales it, effectively stretching it to the x resolution or whatever resolution your TV runs so that it can fill the entire screen.
If you've ever changed the resolution on your computer to a lower resolution, your computer monitor will do the same thing. It will scale it to fill the entire monitor.
This has to be done because there are a set physical number of pixels in the display and the image must be scaled to that resolution to be displayed properly. Scalers can be very helpful if you have several video sources and you want to run them all through a single connection on a display.
Also, they are often used when your source signal resolution doesn't match a resolution supported by your display. A scaler by itself does only this. It is not designed to improve the picture quality of a lower resolution image or enhance it in any other way. When a lot of people talk about a scaler they are referring to a device that will scale the resolution as we've just discussed and also has an image processor in it to try and clean up the image.
The first thing to be aware of is if you are starting with a low resolution image you can never make it look as nice as an image that started at a high resolution.
You cannot make your standard TV channels come through as sharp and with as much detail as an HD channel. A video processor will run the video signal through often many complex algorithms that adjust the video signal to clean up bad noise and to try and sharpen the image.
This will often help with the quality of the picture, but it will never be a substitute for true HD sources. Many HDTVs these days have some form of image processor in them to perform these functions. The same standard definition TV signal may look better on one TV than another because of the type of image processing that is done within the TV. If you want to squeeze the best quality you can out of your standard definition sources you would want to use a nice video processor and scaler that can clean up the image before sending it to your TV.
High Definition , Resolution and Scaling Explained High Definition capabilities have truly become ubiquitous, but understanding HD is still relegated to elite geeks, until now. Not yet. Seeing Pixels? Video Resolution and Scaling Explained. Added to your cart:. Conventional CRT sets display around visible lines of pixels. Broadcasters have been sending signals that work well with this resolution for years, and they can't fit enough resolution to fill a huge television into the analog signal.
Analog pictures are interlaced -- a CRT's electron gun paints only half the lines for each pass down the screen. On some TVs, interlacing makes the picture flicker.
Converting video to analog format lowers its quality. The picture, even when displayed on a small TV, is better quality. A digital signal can support a higher resolution, so the picture will still look good when shown on a larger TV screen.
The video can be progressive rather than interlaced -- the screen shows the entire picture for every frame instead of every other line of pixels. TV stations can broadcast several signals using the same bandwidth. This is called multicasting. If broadcasters choose to, they can include interactive content or additional information with the DTV signal. It can support high-definition HDTV broadcasts. Important Digital TV Dates. DTV vs.
HDTV " ". Aspect ratio - Standard television has a aspect ratio -- it is four units wide by three units high. HDTV has a aspect ratio, more like a movie screen. The highest HDTV resolution is x pixels. Frame rate - A set's frame rate describes how many times it creates a complete picture on the screen every second. DTV frame rates usually end in "i" or "p" to denote whether they are interlaced or progressive. DTV frame rates range from 24p 24 frames per second, progressive to 60p 60 frames per second, progressive.
Buying an HDTV " ". If a station near you is broadcasting in HDTV, you can attach an antenna to an integrated set and watch the station in high definition. This is the option for you if you want to have HDTV capabilities later on but aren't ready for the financial commitment now. Your picture quality will still be better than on your old TV, but it won't be high definition until you get an HDTV receiver. Equipment and Signal " ". If so, think of it this way. It takes that many lines of video information to put together such a detailed picture that appears lifelike.
But lines is standard definition. Today's high - definition televisions have vertical display resolutions of either or 1, lines! Such high resolution is what gives HD video its sharpness and eye-popping realism. To watch high - definition video , you need both a high - definition source and a high - definition monitor.
High - definition monitors usually come in the form of a wide variety of HD televisions. However, most computer monitors are also capable of displaying high - definition video. So, if you don't have an HDTV, you can usually still enjoy high - definition video on your computer. If you're in the market for an HDTV, should you definitely go for the most expensive television with the highest resolution? Not necessarily…electronics experts will tell you that all HD video looks great. Unless you buy a very large television, you probably won't be able to tell much difference between the different HDTV resolutions.
Do you live your life in SD or HD? We hope it's HD! Make the most of every day. And make the most of today's Wonder of the Day by exploring one or more of the following activities with a few friends or family members:. That's super cool, Alex! Thanks for sharing your comment with us - what an awesome connection! We like that you are really interested in learning about technology, Team McNeil 1! You sure know a lot and we think it's super cool that your dad teaches you what he knows about it, too!
Give technology a bit more time, and we're sure it will surpass the 1, line resolution mark! Hello, Holly! Thanks so much for sharing what you think about Wonderopolis! We appreciate your comment! Hello, Shawn! Thank you so much for sharing your thoughts about HD and other types of televisions! It's fun to watch television and play video games, Ninja Girl, but we're glad you let us know you still stay active! Thank you for sharing your personal connection to this Wonder, too!
High-definition really DOES make it look like you could reach out and touch what you are watching, Mak! We are undergoing some spring clearing site maintenance and need to temporarily disable the commenting feature.
Thanks for your patience. This is determined by the number of pixels on the screen—older television sets used cathode ray tubes lines of pixels to display images. To qualify as high definition, there should be up to lines of interlaced pixels across the screen. This means more pixels, which will be smaller and closer together. Watching TV used to involve analogue signals, which were often affected by the quality of both your TV set and the weather outside.
The digital signal also allows for more bandwidth than analogue signals, so it can send more audio and video data to our screens.
0コメント