LED grayscale can also be called LED brightness. Gray scale, also known as half tone, is mainly used to transmit pictures. The gray levels are 16, 32, and 64 respectively. It uses matrix processing to process file pixels to 16, 32, and 64 levels. With the improvement of technology, the current mainstream manufacturers use 256 levels. Make the transmission picture clearer. Whether it is a monochrome, two-color or three color screen, the image or animation needs to adjust the light intensity of each LED that constitutes the pixel. The accuracy of the adjustment is usually called the gray level. Do you know the difference between oled and led displays?
The gray level of led display screen mainly depends on the digital to analog conversion bits of the system.
Of course, the video processing chip, memory and transmission system of the system need to provide corresponding bit support. At present, LED display mainly adopts:
8-bit processing system
256 gray levels. There are 256 brightness changes from black to white.
10-bit processing system
1024 gray scale. There are 1024 brightness changes from black to white.
12-bit processing system
4096 gray scale. There are 4096 brightness changes from black to white.
14-bit processing system
16384 gray scale. There are 16384 brightness changes from black to white.
There are two ways to control LED gray: one is to change the current flow, the other is to adjust the pulse width.
Change the current flowing through the LED. Generally speaking, LED tubes allow continuous operating current of about 20 mA. Except for red LED saturation, the gray scale of other LEDs is basically proportional to the flow current;
The human visual inertia and pulse width adjustment are used to realize the gray level control, that is, the periodic change of the light pulse width (i.e., the space ratio). As long as the cycle of repeated illumination is short enough (that is, the refresh rate is high enough), the human eye will not feel that the luminous pixels are shaking. Because pulse width adjustment is more suitable for digital control, almost all LED screens use pulse width adjustment to control the gray level. LED control system is usually composed of main control box, scanning board and display device.
Some factory parameters are processed with 16 bits, but the current technology cannot reach this level.
This is a project of led transparent screen from canada, which is installed in the jungle and is being tested.
How to identify the brightness level of led display
The brightness discrimination level refers to the brightness level of the image that can be distinguished by the human eye from the blackest to the whitest. As mentioned earlier, some display screens have very high gray levels, which can reach 256 or even 1024. However, due to the limited sensitivity of human eyes to brightness, these gray levels cannot be fully recognized. That is to say, many neighboring gray-scale people look the same. And eye discrimination is different for everyone. For the display screen, the higher the level of human eye recognition, the better, because the displayed image is for people to see after all. The more brightness levels the human eye can distinguish, the larger the color space of the display screen, and the greater the potential to display rich colors. The brightness identification level can be tested with special software. Generally, the display screen can reach level 20 or above, which is a good level.
The higher the gray level of LED display screen is, the richer the color is, and the more colorful the color is; On the contrary, the display color is single and the change is simple. Of course, the higher the gray level of the display, the higher the cost. When the gray level of the display screen exceeds the perception limit of the human eye, the performance price ratio of the display screen will decline. When selecting the gray scale parameters of LED display screen, we can select the one that is suitable for us based on the playback effect and cost.
