The Evolution of DVDs
The DVD format supports a natural video resolution of 720 x 480 (480i). When you put a disc into a DVD player, the player reads this resolution. Hence, DVD is classified as a standard resolution format. This worked well when the DVD format debuted in 1997, but DVD player manufacturers soon decided to improve DVD image quality. They implemented additional processing to the DVD signal after it was read off the disc but before it reached the TV. This process is called progressive scan. Progressive scan DVD players output the same resolution as other players but provide a smoother-looking image.
Introduction of DVD Upscaling
Although progressive scan improved image quality on compatible TVs, when HDTV came along, image quality needed more help. In response, DVD makers created a process called upscaling. Upscaling mathematically matches the pixel count of the DVD output signal to the physical pixel count on an HDTV, which is typically 1280 x 720 (720p), 1920 x 1080 (1080i or 1080p), or 3840 x 2160 (2160p or 4K).
720p represents 1,280 pixels displayed across the screen horizontally and 720 pixels down the screen vertically. This means there are 720 horizontal lines on the screen displayed progressively, or each line displayed following another.1080i represents 1,920 pixels displayed across a screen horizontally and 1,080 pixels down a screen vertically. This means there are 1,080 horizontal lines displayed alternately. All the odd lines are displayed, followed by all the even lines.1080p represents 1,080 horizontal lines displayed sequentially. This means all lines are displayed during the same pass.4K (or 2160p) represents 3,480 horizontal lines displayed sequentially. This means all lines are displayed during the same pass.
The Practical Effect of DVD Upscaling
Visually, for the average consumer, there’s not much difference between 720p and 1080i. However, 720p delivers a slightly smoother-looking image because lines and pixels display in a consecutive pattern, rather than in an alternate pattern. Upscaling does a good job of matching the upscaled pixel output of a DVD player to the natural pixel display resolution of an HDTV, resulting in better detail and color consistency. However, upscaling can’t convert standard DVD images into true high-definition (or 4K) images. Upscaling works best with fixed pixel displays, such as plasma, LCD, and OLED TVs. Results aren’t always consistent on CRT-based HDTVs (there aren’t too many of those still in use).
Points to Remember About DVD Upscaling
Here are a few things to keep in mind when working with a DVD player and a newer TV.
Do I Need an Upscaling DVD Player?
You can hook up any DVD player to an HDTV. Upscaling DVD players are better able to match the natural pixel resolution of an HDTV. Still, you may see good results on a standard DVD player that doesn’t have progressive scan or upscaling capability when it’s connected to an HDTV’s provided component or S-video inputs.
Connecting a DVD Player to an HDTV
If you have an HDTV (or 4K Ultra HD TV) and a standard DVD player, use the component video connection (red-blue-green) between the DVD player and the HDTV for best results. If your DVD player is progressive-scan capable, always use this option when connected to a progressive-scan capable TV. However, if your DVD player provides upscaling, it has an HDMI connection, so always use HDMI to access the DVD player’s upscaling capabilities.
True High-Definition Viewing
DVD upscaling is only an approximation of the high-definition viewing experience. To get true high-definition viewing from a disc format, use Blu-ray Disc content with a Blu-ray player connected to an HDTV or 4K Ultra HD TV using HDMI. The Blu-ray Disc format supports 720p, 1080i, and 1080p resolutions.
DVD Upscaling vs. Blu-ray
An upscaled DVD, even when it’s good, can’t match the quality of a natural Blu-ray Disc source. Compared to Blu-ray Disc, an upscaled DVD tends to look flatter and softer, especially in the background. There’s a difference when looking at reds and blues. With upscaled DVDs, reds and blues tend to override underlying detail. The same colors in Blu-ray are tight, with the detail visible under the color.
Blu-ray Makes Content Better
All Blu-ray Disc players can upscale standard DVDs, provided the player is connected to an HDTV or 4K Ultra HD TV using the HDMI connection option. Some Blu-ray Disc players have built-in 4K upscaling for both DVD and Blu-ray Disc playback. If a Blu-ray Disc player doesn’t provide this feature, the 4K Ultra HD TV further upscales the 1080p signal from the Blu-ray Disc player to 4K.
