Basic Concepts of Real Pixels and Virtual Pixels
In LED display technology, "real pixels" and "virtual pixels" are two core pixel display technologies. Through different pixel composition logics and driving methods, they affect the resolution, cost, and applicable scenarios of the display screen. The differences and characteristics of the two are analyzed in detail below.
Definition and characteristics of real pixels
A real pixel is a physically countable, actual pixel on an LED display screen. Each real pixel can independently control its brightness and color, collectively constructing the image on the screen. In a real pixel display, there is a 1:1 correspondence between physical pixels and the actual displayed pixels; the number of pixels on the screen determines the amount of image information that can be displayed.
The light-emitting points of a real pixel are located on the LED tubes, exhibiting a cohesive characteristic. From a technical implementation perspective, each of the red, green, and blue LEDs in a real pixel display ultimately only participates in the imaging of one pixel to achieve sufficient brightness. This design ensures the independence and integrity of each pixel, making the display effect more stable and reliable.
The advantage of a real pixel display lies in the stability and consistency of its display effect. Because each pixel is independently controlled, there is no color mixing problem caused by pixel sharing, making it particularly suitable for applications requiring high-precision display, such as professional film and television production and high-end commercial displays.
Definition and characteristics of virtual pixels
A virtual pixel is a display technique implemented using specific algorithms and control technologies, enabling a display screen to visually present a higher resolution effect than actual physical pixels. Simply put, it "simulates" more pixels using technical means.
Virtual pixel displays utilize LED multiplexing technology. A single LED can be combined with adjacent LEDs up to four times (top, bottom, left, and right), allowing fewer LEDs to display more image information and achieve higher resolution. Virtual pixels are dispersed, with light-emitting points between the LEDs, forming virtual image points through the mixing of adjacent red, green, and blue sub-pixels.
The core of virtual pixels lies in the combination and distribution of physical pixels, allowing the display screen to show more image details and effects than actual pixels. It can display two or four times more image pixels than the actual pixels on the display. For example, when R, G, B are distributed in a 2:1:1 ratio, a single pixel consists of two red LEDs, one green LED, and one blue LED, thus making the displayed image four times the original.
Technical Principles and Implementation Methods
Technical Implementation Principle of Real Pixels
The technology of real-pixel LED displays is based on traditional display control methods, with its core feature being a 1:1 correspondence between physical pixels and display pixels. From a hardware perspective, an LED display consists of pixels composed of LED diodes and related control circuitry, enabling precise control over the brightness and darkness of each pixel to display rich information.
The core of an LED (Light Emitting Diode) is a PN junction composed of P-type and N-type semiconductors. When a forward voltage is applied to the PN junction, electrons and holes recombine at the junction, releasing energy as photons, thus emitting light. LEDs made of different materials emit different colors of light; for example, gallium phosphide (GaP) LEDs typically emit green light, while gallium arsenide (GaAs) LEDs emit red light.
In a full-color LED display, each pixel consists of three LEDs: red, green, and blue. By controlling the brightness and darkness of the different colored LEDs in each pixel, rich and varied images and videos can be created. To precisely control the brightness and color of each pixel on an LED display, a corresponding driving circuit is required. Common driving methods include static driving and dynamic driving. Static driving refers to each pixel having its own independent driver chip for control. This method produces good display results and uniform brightness, but the circuitry is complex and the cost is high. It is generally used in applications with a small number of pixels and extremely high display quality requirements. Dynamic driving, on the other hand, uses a scanning method, lighting up different rows and columns of pixels in turn, utilizing the persistence of vision in the human eye to achieve the display of a complete image.
Technical Implementation Principles of Virtual Pixels
Virtual pixel technology is a display control scheme that achieves an equivalent resolution increase by mapping physical pixels to display pixels (N=2 or 4). Its core technology lies in rearranging the LED tubes between physical pixels to form a combination of virtual pixels. Virtual pixels employ a distributed light-emitting structure, forming virtual pixels by mixing adjacent red, green, and blue sub-pixels.
In specific implementation, virtual pixel technology has several solutions. Taking the four-lamp RGGB dynamic sub-pixel rendering technology as an example, in a physical pixel arrangement, the three RGB sub-pixels within each black frame form a complete pixel for content display. However, in a four-lamp RGGB arrangement, each black frame contains only one sub-pixel. Through advanced dynamic sub-pixel rendering technology, surrounding sub-pixels can be flexibly borrowed according to the image content, allowing a single sub-pixel to achieve complete pixel content display.
Compared to physical pixels, in a four-lamp RGGB arrangement, each (RGB) pixel only needs to add one sub-pixel (G) to achieve a 4-fold increase in display effect. Similarly, the three-lamp Delta1 vertical dynamic sub-pixel rendering technology also achieves high-resolution display by flexibly borrowing surrounding sub-pixels.
Virtual pixels can be categorized by their control method (software virtual vs. hardware virtual), their multiplier (2x virtual vs. 4x virtual), and their LED arrangement (1R1G1B virtual vs. 2R1G1B virtual). In the 2R1G1B virtual pixel scheme, each diode can share four pixels, significantly improving display resolution.
Comparative Analysis of Technical Characteristics
Comparison of display effects
Because each pixel in a real-pixel display is independently controlled, the display effect is more stable and accurate. When displaying single-stroke text, a real-pixel display can present clear text, while a virtual-pixel display may show unclear text. This is because virtual pixels use time-division multiplexing, cyclically scanning the information of four adjacent pixels, which may result in less sharp edge details.
In terms of color performance, real-pixel displays have more accurate and consistent colors because each pixel's RGB subpixel is dedicated to that pixel. Virtual-pixel displays achieve color by mixing the subpixels of adjacent pixels, which may lead to color deviation or undersaturation under certain conditions.
From a viewing experience perspective, real-pixel displays maintain good display quality at any viewing distance, while the optimal viewing distance for virtual-pixel displays needs to be greater than 2048 times the physical pixel pitch of the monitor screen. At close-up viewing distances, virtual-pixel images may appear grainy, especially around static text where jagged edges may appear.
Cost and performance balance
Real-pixel displays are relatively expensive due to the need for more physical LEDs and driver circuitry. Especially in high-resolution applications, the cost of real-pixel solutions increases exponentially. Virtual pixel technology, by reusing LEDs, can provide higher resolution and clearer image quality with little or no increase in the number of LEDs, significantly reducing costs.
From a performance perspective, virtual pixel technology achieves higher resolution and clearer visual effects at a lower cost. For customers seeking high-resolution, high-definition, and cost-effective LED displays, virtual pixel displays are an excellent solution. Especially in applications with longer viewing distances, the display effect of virtual pixels can approach that of real pixels, but at a significantly lower cost.
However, virtual pixel technology does have inherent limitations in image quality; at suitable viewing distances, its display effect is acceptable. Existing manufacturers have products that achieve near-real-pixel display effects, especially in scenarios such as conference rooms, offices, and commercial applications where close-view display quality requirements are not high, where virtual pixel technology has a clear advantage.
Application Scenarios and Typical Cases
Application Scenarios of Real-Pixel Displays
Real-pixel displays, due to their stable display effect and accurate color, are widely used in professional fields with high image quality requirements:
High-end Commercial Displays:** In luxury retail, high-end hotels, and other venues, real-pixel LED displays can present accurate colors and delicate images, enhancing brand image and customer experience. For example, the 440-meter-long outdoor curved LED screen built by Visionox in Dubai, using real-pixel technology, became the longest outdoor fixed LED screen in the Middle East and even globally.
Film Production and Virtual Shooting:** The film and television industry has extremely high requirements for display precision, making real-pixel displays the preferred choice. For example, in the "Life Art-Immersive Digital Exhibition of Mawangdui Han Dynasty Culture" at the Hunan Provincial Museum, Unilumin Technology customized a 15-meter-diameter LED acoustically transparent immersive dome space using real-pixel technology, resulting in clear, delicate images and rich, vibrant colors.
Large-Scale Event Venues:** At large-scale events such as sporting events and concerts, audiences need clear and stable images on large screens. Real-pixel displays can meet the need for high definition even when viewed from a distance, such as the 490+ square meter screen installed by Absen at the Jingshan International Tennis Center.
Application Scenarios of Virtual Pixel Displays
Virtual pixel technology, with its high cost-effectiveness, has been widely applied in the following fields:
Virtual Shooting and XR Technology: Virtual pixel technology significantly lowers the cost barrier for virtual shooting. For example, the world's largest single-unit LED virtual studio, jointly built by Absen and Bocai Media, has a total screen area of approximately 1700 square meters and uses virtual pixel technology to break the global record for the number of pixels on a single screen with 600 million pixels. This technology enables film and television production to achieve a revolutionary experience of "zero post-production" and "what you see is what you get."
Mid-range Commercial Display: In shopping malls, exhibition halls, and other occasions requiring large display areas but with limited budgets, virtual pixel displays can achieve high-resolution effects at a lower cost. For example, Unilumin Technology's virtual shooting system and solutions have been applied in multiple projects such as Hengdian Studio No. 1 and Beijing Starlight VP Virtual Studio.
* **Education and Training: Virtual pixel technology is also widely used in the education sector. For example, Aoto Electronics built virtual shooting studios for universities such as Hubei University of Technology's Digital Art Industry College and Beijing Film Academy, providing convenience for teachers and students to learn and master virtual shooting technology.
Technical Parameters and Performance Indicators
Technical parameters of real pixel display
The technical parameters of a real-pixel display typically include the following aspects:
Pixel Density: This refers to the number of pixels per unit area, usually expressed in dots per square meter (dD/m²). For example, a real-pixel display with a physical dot pitch of 10mm has a physical density of 10,000 dots per square meter (m²). Higher pixel density results in finer image display, but requires more LEDs, increasing manufacturing costs.
Brightness: Real-pixel displays typically have high brightness. Indoor screens have a dot diameter of 3-8mm, while outdoor screens have a dot pitch range of PH10-PH37.5. Brightness needs to be adjusted according to the environment; outdoor light sources are strong, requiring over 5000 cd/m²; indoor light is weaker, requiring only 1800 cd/m².
Grayscale Level: This reflects the display's ability to control brightness levels. High grayscale is widely used in image processing, medical imaging, and other fields. A typical 14-bit display provides 16384 levels of grayscale (2^14), dividing the display from darkest to brightest into 16384 parts. Higher grayscale levels result in richer colors. Contrast ratio: This refers to the ratio of the maximum brightness of an LED display screen to the background brightness under a given ambient light level. For LED displays, a contrast ratio of 5000:1 or higher is recommended for optimal performance. High contrast ratio can make images more vivid, but excessively high contrast ratios may lead to a loss of image detail.
Technical parameters of the virtual pixel display screen
Virtual pixel displays, while maintaining core parameters, achieve performance improvements through technological optimization:
Equivalent Resolution: The number of physical pixels on a virtual pixel display is approximately 1 (N=2, 4) times the number of pixels actually displayed, meaning it can display 2 to 4 times more pixels than the actual pixels. For example, in a 2R1G1B virtual pixel solution, each diode can share 4 pixels.
Refresh Rate: High refresh rates shorten frame time and increase refresh frequency, resulting in smoother display. Virtual pixel displays typically employ ultra-high refresh rates of 7680Hz and 1/8 scan rates to effectively eliminate flicker and jitter in traditional photography.
Color Performance: Virtual pixel displays achieve full-color display through the combination of three primary colors (red, green, and blue). Pixel reuse control technology maintains a scan frequency above 240Hz to eliminate screen flicker while reducing energy consumption and cost, adapting to high dynamic range scenarios such as television broadcasting.
Power Consumption Control: Virtual pixel technology optimizes power consumption by reducing the number of physical LEDs. The average power consumption of a certain virtual pixel screen is about 600W/m2, and the maximum power consumption is ≤1000W/m2, which is significantly lower than that of a real pixel screen.
Industry Evaluation and Development Trends
Expert Evaluation of the Two Technologies
Industry experts offer objective assessments of real-pixel and virtual-pixel technologies: Carlette stated, "With the rapid development of display technology, users' demand for higher-definition products is increasing daily. The emergence of virtual pixels can increase product resolution without increasing costs, which is beneficial for promoting the industry's high-definition development." Virtual pixels are a method of pixel reuse that can provide higher resolution and clearer image quality without increasing or only by a small number of LEDs.
However, experts also point out the limitations of virtual pixel technology. Due to the sharing of pixels, the actual display effect of virtual pixels deteriorates as the virtual magnification increases. At close-up viewing distances, the image will appear grainy, especially static text, which will show jagged edges. This means that virtual pixel technology cannot completely replace real pixels in professional applications.
Regarding real-pixel technology, experts believe its advantages in display quality are undeniable, especially in high-end applications. However, with continuous optimization of virtual pixel technology, the gap between the two is narrowing. At appropriate viewing distances and application scenarios, virtual pixels can already provide a visual experience close to that of real pixels.
Future Development Trends
The development of LED display technology exhibits the following trends:
Continuous Optimization of Virtual Pixel Technology: In recent years, the four-lamp virtual pixel scheme has become increasingly common. In the virtual green four-lamp scheme, each pixel consists of four LEDs: red, green, blue, and virtual green. In a complete display cycle, each red/blue LED is reused four times, and each green/virtual green LED is reused twice. Combined with a 14-bit high-precision control system, the display quality of virtual pixels will be further improved.
Expanding Application Scenarios: The number of LED virtual shooting studios is rapidly increasing, reaching 41 nationwide, distributed across multiple provinces and cities including Beijing, Shanghai, and Guangdong. With the popularization of virtual production and 8K video, LED displays are upgrading from a single display function to a "shooting-friendly" solution.
Technological Integration and Innovation: Innovations such as intelligent synchronization technology, optical structure optimization, and adaptive control systems are constantly emerging. Developing refresh rate adjustment systems that dynamically match the frame rate of shooting equipment reduces flicker caused by frequency differences; and using technologies such as diffusion films and microstructure surface treatments reduces the probability of moiré patterns.
Further Innovation: The market continues to expand: Market research indicates that the global Micro LED market size is projected to grow from approximately $100 million in 2020 to over $1 billion in 2025, representing a compound annual growth rate (CAGR) of over 30%. Virtual pixel technology will be a significant driver of this growth, particularly in the consumer market.
