As we all know, outdoor led display screens are widely used at present. Outdoor publicity, traffic guidance, advertising broadcasts, etc. will involve outdoor led display large screens. Outdoor led display screens are the most problematic among many led display screens, because the outdoor environment is inherently complicated. , Such as inclement weather, high temperature, etc., but today we are focusing on the water ripple phenomenon of outdoor led display screens.
Outdoor led display
1. Full-color LED display "Water ripple" scientific name "Moore"
When shooting with a digital camera, if there are dense grain textures, inexplicable water wave-like streaks will often appear. This is the moiré pattern. Simply put, the moiré pattern is a manifestation of the beat principle. Mathematically speaking, two equal-amplitude sine waves with close frequencies are superimposed, and the amplitude of the synthesized signal will change according to the difference between the two frequencies.
2. The difference between water ripple and scanning line phenomenon of full-color LED display
1. Water ripples: generally present an irregular arc-shaped diffusion state!
2. Scanning line: the horizontal black stripes are straight lines, mainly due to the low refresh of the display screen, which is captured and presented by the camera!
Outdoor led display
Third, the process of moiré generation in a full-color LED display
1. Two stripes with slightly different spatial frequencies have the same position of the black line at the left end. Due to the different spacing, the gradually line stripes to the right cannot be overlapped.
2. The two stripes overlap, and the white line can be seen because the black line overlaps on the left. The right side is gradually misplaced, the white line is facing the black line, and the overlap result becomes completely black. There are white lines and all black changes, forming a moiré pattern.
Fourth, the process of LED full-color display moiré phenomenon
The pixel distribution density of the full-color display is exactly in the interval that the CCD can distinguish. The inevitable digital camera will still interpret some of the recognizable results, but it will also add unrecognizable grayscale areas. The sum of the two Regular lines will be formed, and the reflection will be visually periodic ripples.
Five, the method to eliminate moiré
1. Change the camera angle. Since the angle of the camera shooting objects will cause moiré, slightly changing the angle of the camera, by rotating the camera, you can eliminate or change any moiré that exists.
2. Change the camera position. In addition, by moving left and right or up and down to change the angle relationship, moiré can be reduced.
3. Change the focus. Too sharp focus and high detail may cause moiré. Changing the focus slightly can change the sharpness and help eliminate moiré.
4. Change the focal length of the lens. Different lens or focal length settings can be used to change or eliminate moiré.
5. Use a front filter to install directly in front of the CCD to make the exposure conditions meet the spatial frequency, thoroughly filter the high spatial frequency part of the image, and reduce the chance of moiré on the LED display, but this will also reduce the sharpness of the image. Spend.
6. Use software to process. Such as NikonCapture or Photoshop plug-ins, etc., to eliminate any moiré on the final image.
Outdoor led display
The above is the treatment method and related knowledge of outdoor LED display water ripple phenomenon. I hope it will help you to further understand the LED display. The LED display has become the most popular large-screen display in the world, and it will be a long time in the future. Metropolis occupies a major position in the market, and related industries will also develop day by day and flourish.
