TV’s are playing an increasingly powerful role in the lives of people around the world. A vehicle to inform, educate, and entertain, they are one of the most popular devices to help people get closer to reality and experience more of the world around them.
We can all agree that the pandemic increased our screen time and accelerated the demand for high quality video content. At a time when many parts of the globe are still out of reach, appetite for content continues to soar, TV’s are our gateway to discovering and connecting with culture and humanity.
Central to this—although it may not seem obvious at first—the colors we see on screen have a huge impact on how we experience what we are watching. Whether it is a movie, a documentary, or a daily news report, the more accurate the colors are on screen, the more we are empowered to explore new worlds in stunning detail and evoking deep emotional responses.
The three critical factors that create superior color accuracy are the smallest Delta E (ΔE) value, color gamut switching capability, and a strong picture quality tuning algorithm. When these three factors come together in harmony, a TV gets us closer to reality, allowing us to experience scenes as if we were actually there in person.
Limitations in Traditional TVs
In the early days, when TV’s were first developed, limitations in coding and decoding technology impacted the overall picture quality, making colors dimmer and less true-to-life than what we see in the real world. Advancements in technology, including the development of DCI-P3, a wide gamut color space for videos, enabled enhanced TV picture quality and colors that were more aligned to what was originally captured on TV and movie sets.
In response to this breakthrough, the display industry rolled out products supporting wide color gamut, leading to innovative TV technology which enabled people to record, distribute, and enjoy content that is closer to reality.
Achieving ΔE 0.86: The Best Color Accuracy in the TV Industry
ΔE is a metric for understanding how the human eye perceives color difference, which is a key indicator to measure the gap between the color displayed on TV and the original color in the TV industry. The smaller the number is, the more accurate the colors are and the more true-to-life the visuals are.
Currently, the smallest ΔE value achieved is 0.86, which is no easy feat, as professional display devices have a ΔE value of less than two, while only a few cutting-edge products in the entire industry have a ΔE value lower than one.
Achieving a ΔE value of below one requires significant investment by an engineering team in order to optimize the way the three primary colors are displayed on screen. The color accuracy of blue needs to be at 1.3 to deliver the same stunning deep blue hues that would originally be captured by a movie camera. For green, the value needs to be at 1.4 for a spot-on reflection of the original shade.
Now, red is the most challenging color to reproduce on screen and is one of the most important colors when it comes to TV’s. As the main color used to show off different skin tones, the shade of red that is displayed on screen has a major impact on overall picture quality. When the color accuracy of red is at 3.5, there is an obvious difference between the color that was captured and the color that is delivered on screen.
When the color accuracy decreases down to 1.5, the quality significantly improves and is more aligned to the original image.
Li Jian is CEO on Duty and General Manager of the Display Technology Division at SKYWORTH TV.
Color Gamut Switching: Smart Algorithms that Cater to Different Video Sources
With most TV programs shot using a BT.709 color gamut, and some movies supporting a DCI-P3 color gamut, playing content with different color gamut on TV’s which are incapable of conducting color gamut switching, can lead to noticeable color discrepancies and impact the overall viewing experience.
To adapt to video content with different color formats and reduce color deviation, it is crucial that a picture quality team constantly fine-tunes colors through various software algorithms, delivering optimized color standards. With smart color gamut switching, TV’s are capable of switching from one color gamut to another upon detecting the color standard in a video source, achieving accurate colors for all to play and watch.
Fine Tuning: Vibrant Picture Quality for an Enhanced Viewing Experience
Now onto the third critical factor: picture quality optimization. To do such fine-tuning, there are seven dimensions an engineering team needs to consider, including local dimming, noise reduction, clarity, color, contrast, MEMC and HDR.
This requires a comprehensive and professional library of picture quality test sequences that can guide engineers to carry out adjustments in such precision. The collection of raw materials should consist of color, noise, motion, clarity and contrast, in the form of pictures and videos in large quantities to train and enhance machine learning. Backed by stringent testing and advanced technologies, the resulting TV is able to auto-adjust colors no matter what the source file is.
One of the lessons we learnt from the pandemic was just how much we rely on technology. As such it is essential for the display industry to continue to innovate and work together to create smarter TV’s boasting brilliant picture quality and a wide variety of functions to make life more convenient, connected and colorful for people everywhere.
That will require more strategic investment from technology companies in research and development and production lines, as well as open dialogues among like-minded industry partners to chart the way forward.
