Picture Quality of a Component Cable Vs. HDMI

Component and HDMI cables support HD signals.

Component cables and HDMI both transmit full 1080p HD signals and are widely compatible with most home video equipment being made today. However, they are different formats, each with its own pros and cons. While many audio/video experts and home theater enthusiasts are quick to point out their preferred format, it's becoming clear that neither one is a clear winner when it comes to picture quality.

Component Definition

Component video cables transmit a video signal that is split across three separate cable components. These cables are called Y, Pb and Pr. The Y cable (which is green) transmit the brightness of the signal. The Pb (blue) and Pr (red) cables transmit the blue and red color information respectively. Information from all three cables create the green components of the signal. Component video is an advancement over composite video, which transmitted video via a single video cable--leading to heavy compression and picture interference. Most HDTVs and home video devices support component video.

HDMI Definition

HDMI is a digital video format, transmitting video signals via a digital-information binary code that is interpreted by a display device like an HDTV or computer monitor, and decoded into a visible picture. While component video splits a video signal into three separate cables, HDMI carries both audio and video on a single cable, leading many to prefer HDMI for its convenience and ease of use. HDMI has become standard on almost every HD-supported device made today. Outputs for the format are found on HDTVs, DVD players, Blu-ray players, video game consoles and even video cards for computers.

Component Weaknesses

Component video is analog, so any digital signal they are transmitting has to first be converted to analog. Some believe this conversion process can slightly degrade the video signal. Further hindering the picture quality of component video are its limitations in bandwidth. An analog signal cannot transmit as much data as a digital signal. This means the signal has to be compressed in order to fit on the analog signal, which can also hurt picture quality. Component cables, like all analog cables, can be subject to interference from outside radio waves or other video signals as well, although most newer cables are shielded to protect against this.

HDMI Weaknesses

Unlike an analog signal, HDMI is not subject to outside interference from radio waves or other signals, and it does not need to be compressed or transferred from one format to another. There are, however, specific issues that can damage the picture quality of a video signal that are unique to HDMI. Unlike component cables, the signal of an HDMI cable degrades over time and distance. The longer an HDMI cable is, the greater the chance that information in the digital signal will be "lost" due to errors in the transmission or connection issues. This can create visual glitches in the picture or create an overall degradation in picture quality.

HDMI or Component?

The question of which format has the better picture quality is hard to answer. While the general consensus seems to be that HDMI is better because it's a digital signal, some say that the difference between the analog component signal and the digital HDMI signal is nearly impossible to see with the naked eye. A guide at the online cable store Blue Jeans Cable says that there is no clear answer, and that it depends solely on the display device and source of the signal; some can transmit better via HDMI, while others do better with component cable. The fact that the debate continues to rage on seems to add credence to the idea that even if HDMI is truly better than component video, the difference is negligible.

References

• Crutchfield: Choosing Audio and Video Cables
• The DV Show: Which has better quality when transferring video: S-Video or composite?
• Projector Central: So what is "Component Video" anyway?
• Blue Jeans Cable: HDMI versus Component Video --Which is Better?
• Blue Jeans Cable: Digital Cables and Analog Cables-- What's the Difference?

Resources

• HDMI.org: Official HDMI Homepage