The resolution of video sources
For Digital Future | September 11, 2008
The two resolutions of the most common sources of high definition video resolutions are 720p and 1080i. All broadcasts high-definition television, use one of these formats. 1080i is the most common, but both formats have their advantages and limitations:
- 1080i has more lines and pixels to display details, making it ideal for programs with slow movements, with many details such as documentaries. But the "i" says it is an interlaced format, which means fewer video frames per second, so it can not handle fast movements of the video as 720p.
- The "p" in 720p format said it was a progressive scan, which means introducing more quick clean. It is ideal for sports and action scenes.
As you can check not speak 1080p format. The reason is that it is a little used as a video source. Is mainly found in Blu-ray and video game consoles like the Xbox 360 and PS3, although you can also enjoy some 1080p sources on satellite television. However, when you hear talk of 1080p, is usually referring to the resolution of a television screen.
Another key thing to understand more about the resolution of video sources that can limit the final resolution of the screen. If you provide a source of TV a lower resolution, as an analog TV channel, a high definition screen can not transform a poor image resolution in a high-resolution image.
As mentioned before, "i" means interlaced scanning and "p" means progressive scan. These terms originated with tube televisions, which painted line at the images on the screen. Interlace scanning images requires two steps to create a full-frame video (a pint of lines and the other odd) while Progressive scan displays the entire frame with a single step. The frame rate for interlaced video is 30 frames per second, while the progressive scan is 60 frames per second.
Interlaced scanning divides each frame into two "camps", showing all the horizontal lines pairs (2,4,6 ...) 1 / 60 second, followed by the odd scanning lines (1,3,5. ..) during the next 1 / 60 of a second. This means that we will see 30 frames per second.
Progressive scan, on the other hand, shows all the lines in a single sweep (1,2,3,4 ...). We will see a full frame every 1 / 60 of a second, ie, 60 frames per second.
Today the majority of digital TV uses progressive scan, but is only relevant when connecting video sources on the TV screen as it should be in the format of the video source to the screen but now there are no problems.
The main thing to remember is that a progressive signal is twice as information interlaced image signal, and generally is a more solid and stable, with a more fluid movement on the screen.
This chart shows the total amount of information displayed in each resolution, per second. The combination of high-resolution screen and progressive scan to deliver twice the image information with the other options, which means a softer image.
Whatever the resolution of the video source material, low-VHS, DVD medium or high in HDTV, the screen automatically provided at the video signal to its resolution. Climb a lower-quality format to accommodate television signals higher resolution screen is called "upconversion" (on-scaling). But this escalation will not see better the original source, not only adapts to see the distorted image.
Similarly, if the source has more pixels than the screen, the video signal has to be "Downconverter" so we lose quality. That is one of the reasons why the 1080p displays are so popular, they can display all the available resolutions without losing information.
- High-definition TV broadcasts
- The resolution of TV screens. Introduction
- The resolution of TV screens
- The technology screens Rear
- Wireless High Definition Interface, the end of the video and audio cables