This year, many mobile phone manufacturers have worked hard on the screen and pursued high refresh rates and resolutions. This is another significant improvement after the popularization of “full screen”. OPPO’s upcoming Find X2 screen not only supports 3K @ 120Hz, but also uses a 10bit color depth panel, leading the way in terms of display effects.
Compared with parameters such as resolution and color gamut, the concept of color depth generally does not appear in mobile phone conferences. For most ordinary users, if you have not actually experienced the product, you may not be very impressed with this parameter.
What is color depth?
Most of the screens on the market use RGB and its derived RGB Pentile (P row) and other arrangements. Each pixel is composed of three colors: red, green, and blue.
Color depth refers to the gray value of the color of each channel, that is, the brightness information, which is represented by the power of n. With 1bit color depth, a single channel can only display 2 ^ 1 = 2 colors, that is, black and white. Under the aforementioned 10bit color depth, each channel of RGB can display 2 ^ 10 = 1024 colors, and then multiply the three 1024 to get all the colors that can be displayed, which is about 1 billion.
△ Low color depth processed picture
The more the color depth, the smoother the color transition of the screen, and the more natural the display of the gradation and other content, the less likely the screen to be broken. 10bit color depth is the current color requirement for ultra-high-definition Blu-ray movies, and it is also one of the common parameters of many high-end retouching displays.
The relationship between color depth and color gamut
We often see that a screen can cover 100% sRGB or 72% NTSC color gamut, which refers to the range of color types that this product can cover within a certain color gamut. According to the previous definition of color depth, some people may think that the display with more color depth will cover a larger color gamut.
However, there is no direct relationship between color gamut and color depth, and there is no definite relationship between different color gamut coverage areas. The more the color depth, the more colors the panel can display. However, each color gamut has a certain range. Only when the extra color of the panel is within this range can the color coverage be improved.
The types of colors that the system can output are limited by the color gamut. At present, sRGB and DCI-P3 are common. When the system outputs the screen, it will issue instructions to the panel through different codes, so the colors supported by the panel are not displayed but are not in the range supported by the system.
At the same time, the number of colors that the system can display is limited by the software and the conditions of the resources being played. For example, many old movies are lower in terms of various parameters due to the constraints of shooting and production. When viewing these contents, we will feel that the picture is not very transparent (film transcription and compression are not discussed here Time loss).
We often find that many displays are marked with 10bit, but the price is only two or three thousand yuan. Products that really use 10bit panels sell for at least five or six thousand yuan. This involves FRC technology, which is pixel jitter.
Pixel dithering can allow some pixels of the display to change quickly, use PWM signals to control the duration, and then use mixed colors to obtain colors that could not otherwise be displayed.
Source: Zhihu @Shieieiki
For example, the RGB value of a color is (133,133,133). The display panel itself cannot display this color, but you can quickly switch some pixels between (130,130,130) and (136,136,136) to get the desired color.
The entire switching process is very smooth, the screen backlight is always on, and only the color is constantly switching, so pixel jitter will not hurt the eyes like PWM dimming. At present, the common pixel dithering is “6 dithering 8” and “8 dithering 10”. The former uses a 6-bit color depth panel to achieve an effect similar to 8-bit.
Although the pixel dithering technology cannot make the display of the panel and the first-class product exactly the same, it can also effectively improve the actual display effect. Without the “8-shake 10” panel, many photography enthusiasts and small studios may not be able to edit and edit 10-bit images at all.
The meaning of 10bit color depth
Finally, let’s discuss what the significance of this 10-bit color screen for OPPO Find X2 for consumers is, can it bring a significant improvement to the user experience?
Earlier we mentioned that 10bit color depth is the current color requirement for high-definition Blu-ray movies, and many photos taken by cameras also support 10bit color depth, and common 8bit screens cannot accurately restore these contents.
△ OPPO Find X2 10bit color depth promotional video
Similar to high refresh rate displays, the parameters including video, photography and other fields have far exceeded the range supported by mainstream mobile phones. At this time, some manufacturers need to improve the configuration of their own products, and then adapt these new technologies to more products through software-level adaptation in order to bring users a better experience.