Understanding of Interlaced and Progressive Scanning on HD TVs

There have been many innovations in the TV industry over the years. From the first generation of TVs to thin， wider HDTV displays today, the industry has evolved and become more advanced. Today, HDTVs provide superior viewing experiences to audiences around the world and the incorporation certain technologies makes this possible. The way that HDTV televisions display content is determined by one of two major technologies, namely interlaced image scanning or progressive image scanning.

Interlaced image scanning has a long history with TV production. It was first used on the analog platform and on a number of SD (standard-definition) TVs. It had a number of benefits such as removing the flickering effect that made video and images hard to view. Interlaced scanning uses separate odd and even lines of images to stitch an image to together. The odd lines are drawn separately on the TV while the even lines are also drawn separately. This creates the stitched like effect. Progressive image scanning first came to light in the early 1990s and went mainstream with the DVD player because it could store and playback content in excellent quality. With progressive image scanning, the image lines are drawn sequentially to create a complete picture, similar to a paint brush effect.

There were a number of reasons why progressive scanning was used for the DVD player platform. Since most cinema and film production companies use the 24p (24 frames progressively per second) standard for recording and making movies, the technology was able to reproduce content without any deinterlacing or flickering of original content. This is not to say that progressive scanning is always better than interlaced scanning. For example, on most broadcast stations today, interlaced scanning is still being used for transmitted images in 1080i at a speed of 60 frames per second, which is the equivalent of 1080p at 30 frames per second.

This means that interlaced scanning uses less bandwidth to broadcast and is better suited for fast paced recording and broadcasting. Progressive scanning is able to display and upscale for stored and digital media better because of its ability to reproduce the content correctly.

Understanding HDTV Screen Sizes and Types

There are different types of HDTVs available today. These include different screen sizes and format types that range from plasmas, LCD/LED, projection and rear projector-based HDTV televisions.

The term HD is used to refer to high-definition and should not be confused with the other HD acronyms for hard drives, which are referred to as HDD. For most HD TV models, the high-definition resolution is used to describe the image quality of video content that is displayed at more than 1280 pixels per 720 lines of resolution. This means that DVD quality resolution, which maxes out at 640 pixels by 480 lines of resolution, is not really HD. HD resolution has been used on PC monitors and displays for a number of years before they were ever introduced for most standard TV viewing. The principle of HD is simple: The more pixels that a line of resolution can display, the more detailed and sharper the image quality. That means that HD resolutions such as 1080p allow for at least 1920 pixels per line compared to the 640 pixels per line used for DVD quality.

Also, the image is displayed natively, meaning that if the image is of lower resolution, it will be up scaled to fit the screen. For example, a 480p picture will be up scaled to fit a 720p HDTV screen. If the image has a higher resolution, it will be downscaled to fit the screen. Again, 1080p will be reduced to fit the 720p screen. Most HD TVs will support one native resolution and will upscale or downscale content to fit the screen. Here are several tips you can use when purchasing your next HD TV:

Consider that HD TV is not the same as HD-ready TV: While very few HD-ready TVs remain, the term refers to being able to display content at the basic HD resolution, which is 720p or 1280 plus pixels per line of resolution. HD TVs support 1080p resolution, which is the native Full HD resolution.

Screen size should not always be the deciding factor. Because the screen resolution is fixed on all HDTVs, there may not always be a benefit to buying a larger HD TV. It will of course depend on your specific requirements. On some HDTV models, the larger screen will be beneficial, such as on a plasma HD screen or a rear-projection HD TV.

Do You Really Need a New HDTV? The Benefits of Buying a Used HDTV

HDTV Televisions have been around for some time. Not only do they produce sharper, more detailed pictures and video but HDTV allows for more channels and features to be added to normal television. Around the world, it is being adopted and broadcasters are broadcasting in 720p, 1080i and 1080p HD resolutions. Each HD resolution is different but since most HDTVs are able to display one or all three native resolutions, having an HDTV today is still a smart option.

Although most consumers will go for new HDTVs, there are other options including buying used HD Televisions. Depending on one’s particular budget, selecting a used HDTV can be a better option than buying brand new for a number of reasons:

Used is the new kind of new: As prices of technology continue to fall and in some instances, grow. It can be difficult to determine what the best price point is for an HDTV especially if you are buying a new HDTV. With used HDTVs, it is possible to find a more feature packed, used or refurbished HDTV for far much less. For the consumer who is price conscious
HD Technology: Aside from newer backlight LED screens, wider screens and the emergence of 3D technology, there isn’t much that has changed in the last several years in the HDTV market. In fact some older generation HDTVs display a more clearer picture resolution than newer HD Televisions available today. This is an important point to consider when considering whether to go used or new.

Accessories still Adapt: If you have a lot of older generation or legacy electronics like older sound systems, A/V receivers, DVD players, cable set-up boxes and video game systems and other accessories, buying a refurbished or used HD television can be the smart option as the HD television may have the right connection ports for your television.

If you do decide to buy used and refurbished, consider HD Televisions that are not older than 4 years, because the average technology development cycle is about that period of time. It is a safe bet to choose a HDTV from the last 4 years because it will be compatible with most current systems (aside from 3D) and also some legacy systems.

All the facts about the evolution of HDTV

The term high definition was first discovered and used to describe television picture quality standards in the 20th century and HDTV televisions have a long history in the evolution of TV and broadcasting. Originally designed to replace then existing systems that were only able to produce 12 lines of picture resolution, different HD television systems were developed and implemented in different countries.

The US used NTSC using 525 lines of resolution while European countries used a PAL system that was capable of producing 625 interlaced lines instead. This led to having separate broadcasting platforms and format until the late 1990s when DVB (Digital Video Broadcasting) was formally introduced and mandated by regulators around the world. It required wide screen transmission creating the need for bigger televisions and the term HDTV was adopted. Formats used previously before the introduction of DVB are now considered Standard Definition although some countries still recognize those formats as high-definition.

Today most HDTVs are able to produce as average of 720 lines of progressive resolutions and full high-definition (Full HD) is recognized as 1080p or 1080 lines of progressive resolution.

Some computer manufacturers have introduced other versions of high definition including Extreme High definition (1440 lines of progressive resolution) and ultra high-definition Television (4320 lines of progressive resolution) although only extreme high definition is available to most consumers and is optimized for computer based LCD monitors, most notably the Apple iMac 27inch which has 1440p as its native resolution.
For most consumers 720 lines of resolution or 720p HD is satisfactory as it still has the benefits of HD and digital compression as full HD.

Lower prices HDTVs support 720p or HD-ready signals while others come with full HD 1080p support built in. While getting a 1080p HDTV or Full HD TV is the ideal option, most broadcasters are broadcasting using 720p HD so most consumers can still buy an HD-ready HDTV without losing out on the HD experience. For those with a big pocket, there are 3D ready Full HD Televisions available that can support 3D as well as 720p and 1080p resolutions. HDTV has evolved from its early days where 13 lines was considered high definition, to where today almost 100 times that is considered extreme high definition.