Digital Displays Things Are Not Always As They Appear
By : David Little | ID: 41378 | Views : 62046 | Words: 769 | Rating : Not Rated The most obvious thing about digital signage is the display panel. It's the first thing you see, and probably the last thing you think about once it's hung and showing the content you want others to see.
But did you know that just because your digital signage messaging is playing back on a flat panel plasma or LCD that it's not necessarily being shown in HD quality? While they're somewhat less common today, for the past few years display makers have marketed right next to the HD panels- something known as ED panels or TVs. EDTV stands for "Enhanced Definition Television" -something that's better, to be sure, than the ordinary television in most homes across America, but nowhere near as good as HDTVs and HD monitors. So, what makes one panel "enhanced" and another "high-def"? Basically, its pixels, scanning and terminology.
Pixels first
If your interest in digital signage is more about what it can do for you than how it does it, you might not be very familiar with some of the basics. First, a pixel is a picture element. Many say it's the smallest picture element in a display, but maybe a better way to think of it is as the smallest whole picture element in a display. That's because just like Gaul, all pixels are divided into three parts -red, green and blue. Those parts are often referred to as sub-pixels. But for the sake of this discussion, let's stick with pixels.
In plasmas and LCDs, pixel count is pretty cut-and-dry. These displays are made up of rows and columns of picture elements or pixels. An SD panel -or standard definition panel, the closest thing to your ordinary home TV- will have 480 rows and 720 pixels across. EDTVs have the same number of rows, 480, and 853 pixels across.
Besides having about 20 percent more pixels across, another important distinction between the two is the type of scanning used. An SD display is interlaced just like your fingers are when you do "Here's the church, and here's the steeple...." Drawing one complete picture, or frame, in an interlaced display requires the monitor to scan the odd number rows in an image sequentially first, i.e. 1, 3, 5 etc. and then the even numbered rows 2, 4, 6 etc. Together those two interlaced "fields" make up a frame. There are about 60 fields per second, or about 30 frames per second in SD video. (I won't trouble you with the why regarding the term "about.")
These interlaced fields are displayed so quickly that the scanned odds are still aglow, although decaying, while the evens are being scanned. However, that decay in the glow and constant refresh account for a flicker that's visible to some.
ED monitors are progress scan displays. Like computer monitors, they scan lines, 1, 2, 3, etc. all the way to line 480. It's the greater number of pixels and this progressive scanning that makes them better than SD, or in other words, enhanced.
Enter HD
HD or high definition can produce a view of the world that's lifelike. If you doubt that, flip on the Discovery Channel and then flip over to Discovery HD on an HDTV. You will be amazed.
There are many different types of high definition standards, but you only have to be concerned about a few things when it comes to digital signage. First and foremost, HD is pixel count. If it's got at least 1280 x 720 pixels, it qualifies as HD. However, here's where things get a little confusing. HDTV and monitors also come with 1920 pixels across and 1080 pixels vertically, and they come with lots of different pixel counts in between. Those "tweeners" have more to do with the manufacturing capabilities and priorities of the company making the panel than they do with the actual HD standard.
Not quite as they seem
Without a doubt, HDTVs are burgeoning in the home and HD panels are becoming popular displays for digital signage. Their ability to reproduce lifelike images is breathtaking. That's powerful clay in the hands of digital signage sculptors.
But don't be confused. Just because a panel is flat, it's not necessarily HD. Look for the panel's resolution in pixels. Find out what type of scanning it uses. Together, those two pieces of information
can tell you what you're looking at, even if your eyeballs aren't sure. It can also save you the headache of mistakenly acquiring the ED monitors that seemed like a steal when you thought you were buying HD.
But did you know that just because your digital signage messaging is playing back on a flat panel plasma or LCD that it's not necessarily being shown in HD quality? While they're somewhat less common today, for the past few years display makers have marketed right next to the HD panels- something known as ED panels or TVs. EDTV stands for "Enhanced Definition Television" -something that's better, to be sure, than the ordinary television in most homes across America, but nowhere near as good as HDTVs and HD monitors. So, what makes one panel "enhanced" and another "high-def"? Basically, its pixels, scanning and terminology.
Pixels first
If your interest in digital signage is more about what it can do for you than how it does it, you might not be very familiar with some of the basics. First, a pixel is a picture element. Many say it's the smallest picture element in a display, but maybe a better way to think of it is as the smallest whole picture element in a display. That's because just like Gaul, all pixels are divided into three parts -red, green and blue. Those parts are often referred to as sub-pixels. But for the sake of this discussion, let's stick with pixels.
In plasmas and LCDs, pixel count is pretty cut-and-dry. These displays are made up of rows and columns of picture elements or pixels. An SD panel -or standard definition panel, the closest thing to your ordinary home TV- will have 480 rows and 720 pixels across. EDTVs have the same number of rows, 480, and 853 pixels across.
Besides having about 20 percent more pixels across, another important distinction between the two is the type of scanning used. An SD display is interlaced just like your fingers are when you do "Here's the church, and here's the steeple...." Drawing one complete picture, or frame, in an interlaced display requires the monitor to scan the odd number rows in an image sequentially first, i.e. 1, 3, 5 etc. and then the even numbered rows 2, 4, 6 etc. Together those two interlaced "fields" make up a frame. There are about 60 fields per second, or about 30 frames per second in SD video. (I won't trouble you with the why regarding the term "about.")
These interlaced fields are displayed so quickly that the scanned odds are still aglow, although decaying, while the evens are being scanned. However, that decay in the glow and constant refresh account for a flicker that's visible to some.
ED monitors are progress scan displays. Like computer monitors, they scan lines, 1, 2, 3, etc. all the way to line 480. It's the greater number of pixels and this progressive scanning that makes them better than SD, or in other words, enhanced.
Enter HD
HD or high definition can produce a view of the world that's lifelike. If you doubt that, flip on the Discovery Channel and then flip over to Discovery HD on an HDTV. You will be amazed.
There are many different types of high definition standards, but you only have to be concerned about a few things when it comes to digital signage. First and foremost, HD is pixel count. If it's got at least 1280 x 720 pixels, it qualifies as HD. However, here's where things get a little confusing. HDTV and monitors also come with 1920 pixels across and 1080 pixels vertically, and they come with lots of different pixel counts in between. Those "tweeners" have more to do with the manufacturing capabilities and priorities of the company making the panel than they do with the actual HD standard.
Not quite as they seem
Without a doubt, HDTVs are burgeoning in the home and HD panels are becoming popular displays for digital signage. Their ability to reproduce lifelike images is breathtaking. That's powerful clay in the hands of digital signage sculptors.
But don't be confused. Just because a panel is flat, it's not necessarily HD. Look for the panel's resolution in pixels. Find out what type of scanning it uses. Together, those two pieces of information
can tell you what you're looking at, even if your eyeballs aren't sure. It can also save you the headache of mistakenly acquiring the ED monitors that seemed like a steal when you thought you were buying HD.
Newsflash
 |
All Categories
|
|
Featured Partners
|
Olympic Games Tickets SEO Services Webcam Chat Car Hire Spain |