Moiré pattern

About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.

Determining TV scan pattern distortions by means of line gratings

Abstract: A highly accurate method is presented for determining TV scan pattern linearity using a dot pattern transparency. This technique allows a standard scan pattern to be compared with both the camera scan pattern and display raster. It displays the difference as moire interference patterns.

Study on Reduction Methods of Moiré Noise in Image Acquisition of Periodic Gray‐Scale Pattern

Abstract: Creating valid digital images for display surfaces is vital for the quantification of display quality (defects, spots) for display devices. However, when imaging a spatially discrete display surface using individual acquisition elements, an acquisition moire appears in the acquisition image. In this paper the authors quantify the display acquisition image, then clarify how to find the acquisition moire from the dimensions of the display system and acquisition target using computations. Based on these results, the authors formulate a method for determining a pixel shift which inverts the moire phase in a pixel-shifted image. They then propose a method to compute the average in pixel units of gradations between a reference image and a pixel-shifted image given by a reference image and a pixel-shifted image created using the above method. Finally, they verify the effects of reducing the acquisition moire using simulations. © 2001 Scripta Technica, Syst Comp Jpn, 33(1): 27–37, 2002

Moiré pattern from a multiple Bragg–Laue interferometer

Abstract: In X-ray section topography of Si 220 diffraction in a multiple Bragg–Laue mode, a moire pattern is observed when the incident beam is divided into two parts by inserting a platinum wire in the middle of the beam. The moire pattern can be explained by the summation of two interference fringes corresponding to the two incident beams. The coherency of the X-rays from the bending-magnet beamline is estimated using the moire pattern.

Method for removing moire of picture data

Abstract: PURPOSE:To provide a method for removing the moire of picture data capable of removing the moire while evading the generation of blurs. CONSTITUTION:In this removing method, a moire pattern extraction process for specifying a part in moire generated pictures where the moire is conspicuous and density fluctuation is less and extracting a moire pattern from the part is executed first. Then, an approximation degree calculation process for allocating a window whose size is same as the moire pattern on the picture data of the moire generated pictures while shifting a position, calculating an approximation degree by collating the pattern of the picture data of the part where the window is allocated with the moire pattern and recording it is executed. Then, for the respective picture elements of the picture data, a correction process for superimposing the moire pattern on the position where the approximation degree obtained in the approximation degree calculation process is highest among window positions where the picture elements are provided, subtracting the value of the moire pattern at the position of the picture element from the density value of the picture element and defining it as the density value of corrected picture data is executed.

A novel micro-displacement measurement system of optic path modulation based on FPGA

Abstract: A method for measuring micro displacement using double gratings and two relative movable optical wedges is described. Based on the theoretic analysis in Talbot image region II in double gratings interferometer, we found that moire fringe only shifts with the optic path variation while its contrast does not decrease with both image distance and the thickness of phased object. A micro-displacement measurement sensor is designed based on this characteristic and verified by MATLAB simulation. In moire fringe hardware detecting system double-grating and phototransistors are employed, through which the moire fringe with the information of displacement is converted to sine electrical voltage in proportion to the intensity of moire fringe. Further than that, the signal process circuit, i.e. direction recognizing, eight-subdivision and counting circuit, is designed by using programmable logic device FPGA. And through the logical and timing simulation by VHDL software, the feasibility of method is proved.