What is the water ripple (moiré pattern) on the LED advertising screen car? The water ripple is different from the scan line, and it generally presents an irregular arc-shaped diffusion state. How did it come about? So why does the LED advertising screen appear water ripples? Is there any way to solve it? Don't worry, let's learn about it with Tuosheng Optoelectronics!

  The process of water ripple generation:

 (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 stripes gradually to the right cannot overlap.

 (2) The two stripes overlap, and the white line can be seen on the left because the black line overlaps. The right side is gradually dislocated, the white line is facing the black line, and the overlapping result becomes completely black. There are variations of white lines and full blacks, forming water ripples (moiré).

  The process of producing water ripples on the LED advertising screen: The pixel distribution density of the LED advertising screen is just within the interval that the CCD can distinguish. The inevitable digital camera will still interpret some of the identifiable results, but it will also add the unidentifiable results. The gray-scale area of the two will form a regular pattern, and the response is a periodic ripple visually.

  The process of water ripple generation and the reasons for the appearance of LED advertising screens are mentioned above. Let's talk about the method of eliminating moiré patterns:

  1. Change the camera angle. Since the angle at which the camera is shooting objects can cause moiré, changing the angle of the camera slightly, by rotating the camera, can remove or alter any moiré that is present.

  2. Change the camera position. Additionally, moiré can be reduced by changing the angular relationship by moving side to side or up and down.

  3. Change the focus. Too sharp focus and high detail can cause moiré, and a slight change in focus can change the sharpness, which in turn helps fire moiré.

  4. Change the focal length of the lens. Different lens or focal length settings can be used to change or eliminate moiré.

  5. Install the filter in front of the mirror directly in front of the CCD, so that the exposure conditions meet the spatial frequency, thoroughly filter the high spatial frequency part of the image, and reduce the chance of moiré, but it will also reduce the sharpness of the image.